relations.test.js

// Copyright IBM Corp. 2013,2019. All Rights Reserved.
// Node module: loopback-datasource-juggler
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT

// This test written in mocha+should.js
'use strict';

/* global getSchema:false, connectorCapabilities:false */
const assert = require('assert');
const bdd = require('./helpers/bdd-if');
const should = require('./init.js');
const uid = require('./helpers/uid-generator');
const jdb = require('../');
const DataSource = jdb.DataSource;
const createPromiseCallback = require('../lib/utils.js').createPromiseCallback;

let db, tmp, Book, Chapter, Author, Reader, Article, Employee;
let Category, Job;
let Picture, PictureLink;
let Person, Address;
let Link;

const getTransientDataSource = function(settings) {
  return new DataSource('transient', settings, db.modelBuilder);
};

const getMemoryDataSource = function(settings) {
  return new DataSource('memory', settings, db.modelBuilder);
};

describe('relations', function() {
  before(function() {
    db = getSchema();
  });

  describe('hasMany', function() {
    before(function(done) {
      Book = db.define('Book', {name: String, type: String});
      Chapter = db.define('Chapter', {name: {type: String, index: true},
        bookType: String});
      Author = db.define('Author', {name: String});
      Reader = db.define('Reader', {name: String});

      db.automigrate(['Book', 'Chapter', 'Author', 'Reader'], done);
    });

    it('can be declared in different ways', function(done) {
      Book.hasMany(Chapter);
      Book.hasMany(Reader, {as: 'users'});
      Book.hasMany(Author, {foreignKey: 'projectId'});
      const b = new Book;
      b.chapters.should.be.an.instanceOf(Function);
      b.users.should.be.an.instanceOf(Function);
      b.authors.should.be.an.instanceOf(Function);
      Object.keys((new Chapter).toObject()).should.containEql('bookId');
      Object.keys((new Author).toObject()).should.containEql('projectId');

      db.automigrate(['Book', 'Chapter', 'Author', 'Reader'], done);
    });

    it('can be declared in short form', function(done) {
      Author = db.define('Author', {name: String});
      Reader = db.define('Reader', {name: String});
      Author.hasMany('readers');
      (new Author).readers.should.be.an.instanceOf(Function);
      Object.keys((new Reader).toObject()).should.containEql('authorId');

      db.autoupdate(['Author', 'Reader'], done);
    });

    describe('with scope', function() {
      before(function(done) {
        Book.hasMany(Chapter);
        done();
      });

      it('should build record on scope', function(done) {
        Book.create(function(err, book) {
          const chaps = book.chapters;
          const c = chaps.build();
          c.bookId.should.eql(book.id);
          c.save(done);
        });
      });

      it('should create record on scope', function(done) {
        Book.create(function(err, book) {
          book.chapters.create(function(err, c) {
            if (err) return done(err);
            should.exist(c);
            c.bookId.should.eql(book.id);
            done(err);
          });
        });
      });

      it('should not update FK', function(done) {
        Book.create(function(err, book) {
          book.chapters.create({name: 'chapter 1'}, function(err, c) {
            if (err) return done(err);
            should.exist(c);
            c.bookId.should.eql(book.id);
            c.name.should.eql('chapter 1');
            book.chapters.updateById(c.id, {name: 'chapter 0', bookId: 10}, function(err, cc) {
              should.exist(err);
              err.message.should.startWith('Cannot override foreign key');
              done();
            });
          });
        });
      });

      it('should create record on scope with promises', function(done) {
        Book.create()
          .then(function(book) {
            return book.chapters.create()
              .then(function(c) {
                should.exist(c);
                c.bookId.should.eql(book.id);
                done();
              });
          }).catch(done);
      });

      it('should create a batch of records on scope', function(done) {
        const chapters = [
          {name: 'a'},
          {name: 'z'},
          {name: 'c'},
        ];
        Book.create(function(err, book) {
          book.chapters.create(chapters, function(err, chs) {
            if (err) return done(err);
            should.exist(chs);
            chs.should.have.lengthOf(chapters.length);
            chs.forEach(function(c) {
              c.bookId.should.eql(book.id);
            });
            done();
          });
        });
      });

      it('should create a batch of records on scope with promises', function(done) {
        const chapters = [
          {name: 'a'},
          {name: 'z'},
          {name: 'c'},
        ];
        Book.create(function(err, book) {
          book.chapters.create(chapters)
            .then(function(chs) {
              should.exist(chs);
              chs.should.have.lengthOf(chapters.length);
              chs.forEach(function(c) {
                c.bookId.should.eql(book.id);
              });
              done();
            }).catch(done);
        });
      });

      it('should fetch all scoped instances', function(done) {
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function() {
            book.chapters.create({name: 'z'}, function() {
              book.chapters.create({name: 'c'}, function() {
                verify(book);
              });
            });
          });
        });
        function verify(book) {
          book.chapters(function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(3);

            const chapters = book.chapters();
            chapters.should.eql(ch);

            book.chapters(function(e, c) {
              should.not.exist(e);
              should.exist(c);
              ch.should.have.lengthOf(3);
              const acz = ['a', 'c', 'z'];
              acz.should.containEql(c[0].name);
              acz.should.containEql(c[1].name);
              acz.should.containEql(c[2].name);
              done();
            });
          });
        }
      });

      it('should fetch all scoped instances with promises', function(done) {
        Book.create()
          .then(function(book) {
            return book.chapters.create({name: 'a'})
              .then(function() {
                return book.chapters.create({name: 'z'});
              })
              .then(function() {
                return book.chapters.create({name: 'c'});
              })
              .then(function() {
                return verify(book);
              });
          }).catch(done);

        function verify(book) {
          return book.chapters.find()
            .then(function(ch) {
              should.exist(ch);
              ch.should.have.lengthOf(3);
              const chapters = book.chapters();
              chapters.should.eql(ch);
              return book.chapters.find()
                .then(function(c) {
                  should.exist(c);
                  ch.should.have.lengthOf(3);
                  const acz = ['a', 'c', 'z'];
                  acz.should.containEql(c[0].name);
                  acz.should.containEql(c[1].name);
                  acz.should.containEql(c[2].name);
                  done();
                });
            });
        }
      });

      it('should fetch all scoped instances with find() with callback and condition', function(done) {
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function() {
            book.chapters.create({name: 'z'}, function() {
              book.chapters.create({name: 'c'}, function() {
                verify(book);
              });
            });
          });
        });
        function verify(book) {
          book.chapters(function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(3);

            const chapters = book.chapters();
            chapters.should.eql(ch);
            book.chapters.find(function(e, c) {
              should.not.exist(e);
              should.exist(c);
              ch.should.have.lengthOf(3);
              const acz = ['a', 'c', 'z'];
              acz.should.containEql(c[0].name);
              acz.should.containEql(c[1].name);
              acz.should.containEql(c[2].name);
              done();
            });
          });
        }
      });

      it('should fetch all scoped instances with find() with callback and no condition', function(done) {
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function() {
            book.chapters.create({name: 'z'}, function() {
              book.chapters.create({name: 'c'}, function() {
                verify(book);
              });
            });
          });
        });
        function verify(book) {
          book.chapters(function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(3);

            const chapters = book.chapters();
            chapters.should.eql(ch);

            book.chapters.find(function(e, c) {
              should.not.exist(e);
              should.exist(c);
              should.exist(c.length);
              c.should.have.lengthOf(3);
              const acz = ['a', 'c', 'z'];
              acz.should.containEql(c[0].name);
              acz.should.containEql(c[1].name);
              acz.should.containEql(c[2].name);
              done();
            });
          });
        }
      });

      it('should find scoped record', function(done) {
        let id;
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function(err, ch) {
            id = ch.id;
            book.chapters.create({name: 'z'}, function() {
              book.chapters.create({name: 'c'}, function() {
                verify(book);
              });
            });
          });
        });

        function verify(book) {
          book.chapters.findById(id, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.id.should.eql(id);
            done();
          });
        }
      });

      it('should find scoped record with promises', function(done) {
        let id;
        Book.create()
          .then(function(book) {
            return book.chapters.create({name: 'a'})
              .then(function(ch) {
                id = ch.id;
                return book.chapters.create({name: 'z'});
              })
              .then(function() {
                return book.chapters.create({name: 'c'});
              })
              .then(function() {
                return verify(book);
              });
          }).catch(done);

        function verify(book) {
          return book.chapters.findById(id)
            .then(function(ch) {
              should.exist(ch);
              ch.id.should.eql(id);
              done();
            });
        }
      });

      it('should count scoped records - all and filtered', function(done) {
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function(err, ch) {
            book.chapters.create({name: 'b'}, function() {
              book.chapters.create({name: 'c'}, function() {
                verify(book);
              });
            });
          });
        });

        function verify(book) {
          book.chapters.count(function(err, count) {
            if (err) return done(err);
            count.should.equal(3);
            book.chapters.count({name: 'b'}, function(err, count) {
              if (err) return done(err);
              count.should.equal(1);
              done();
            });
          });
        }
      });

      it('should count scoped records - all and filtered with promises', function(done) {
        Book.create()
          .then(function(book) {
            book.chapters.create({name: 'a'})
              .then(function() {
                return book.chapters.create({name: 'b'});
              })
              .then(function() {
                return book.chapters.create({name: 'c'});
              })
              .then(function() {
                return verify(book);
              });
          }).catch(done);

        function verify(book) {
          return book.chapters.count()
            .then(function(count) {
              count.should.equal(3);
              return book.chapters.count({name: 'b'});
            })
            .then(function(count) {
              count.should.equal(1);
              done();
            });
        }
      });

      it('should set targetClass on scope property', function() {
        should.equal(Book.prototype.chapters._targetClass, 'Chapter');
      });

      it('should update scoped record', function(done) {
        let id;
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function(err, ch) {
            id = ch.id;
            book.chapters.updateById(id, {name: 'aa'}, function(err, ch) {
              verify(book);
            });
          });
        });

        function verify(book) {
          book.chapters.findById(id, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.id.should.eql(id);
            ch.name.should.equal('aa');
            done();
          });
        }
      });

      it('should update scoped record with promises', function(done) {
        let id;
        Book.create()
          .then(function(book) {
            return book.chapters.create({name: 'a'})
              .then(function(ch) {
                id = ch.id;
                return book.chapters.updateById(id, {name: 'aa'});
              })
              .then(function(ch) {
                return verify(book);
              });
          })
          .catch(done);

        function verify(book) {
          return book.chapters.findById(id)
            .then(function(ch) {
              should.exist(ch);
              ch.id.should.eql(id);
              ch.name.should.equal('aa');
              done();
            });
        }
      });

      it('should destroy scoped record', function(done) {
        let id;
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function(err, ch) {
            id = ch.id;
            book.chapters.destroy(id, function(err, ch) {
              verify(book);
            });
          });
        });

        function verify(book) {
          book.chapters.findById(id, function(err, ch) {
            should.exist(err);
            done();
          });
        }
      });

      it('should destroy scoped record with promises', function(done) {
        let id;
        Book.create()
          .then(function(book) {
            return book.chapters.create({name: 'a'})
              .then(function(ch) {
                id = ch.id;
                return book.chapters.destroy(id);
              })
              .then(function(ch) {
                return verify(book);
              });
          })
          .catch(done);

        function verify(book) {
          return book.chapters.findById(id)
            .catch(function(err) {
              should.exist(err);
              done();
            });
        }
      });

      it('should check existence of a scoped record', function(done) {
        let id;
        Book.create(function(err, book) {
          book.chapters.create({name: 'a'}, function(err, ch) {
            id = ch.id;
            book.chapters.create({name: 'z'}, function() {
              book.chapters.create({name: 'c'}, function() {
                verify(book);
              });
            });
          });
        });

        function verify(book) {
          book.chapters.exists(id, function(err, flag) {
            if (err) return done(err);
            flag.should.be.eql(true);
            done();
          });
        }
      });

      it('should check existence of a scoped record with promises', function(done) {
        let id;
        Book.create()
          .then(function(book) {
            return book.chapters.create({name: 'a'})
              .then(function(ch) {
                id = ch.id;
                return book.chapters.create({name: 'z'});
              })
              .then(function() {
                return book.chapters.create({name: 'c'});
              })
              .then(function() {
                return verify(book);
              });
          }).catch(done);

        function verify(book) {
          return book.chapters.exists(id)
            .then(function(flag) {
              flag.should.be.eql(true);
              done();
            });
        }
      });

      it('should check ignore related data on creation - array', function(done) {
        Book.create({chapters: []}, function(err, book) {
          if (err) return done(err);
          book.chapters.should.be.a.function;
          const obj = book.toObject();
          should.not.exist(obj.chapters);
          done();
        });
      });

      it('should check ignore related data on creation with promises - array', function(done) {
        Book.create({chapters: []})
          .then(function(book) {
            book.chapters.should.be.a.function;
            const obj = book.toObject();
            should.not.exist(obj.chapters);
            done();
          }).catch(done);
      });

      it('should check ignore related data on creation - object', function(done) {
        Book.create({chapters: {}}, function(err, book) {
          if (err) return done(err);
          book.chapters.should.be.a.function;
          const obj = book.toObject();
          should.not.exist(obj.chapters);
          done();
        });
      });

      it('should check ignore related data on creation with promises - object', function(done) {
        Book.create({chapters: {}})
          .then(function(book) {
            book.chapters.should.be.a.function;
            const obj = book.toObject();
            should.not.exist(obj.chapters);
            done();
          }).catch(done);
      });
    });
  });

  describe('hasMany through', function() {
    let Physician, Patient, Appointment, Address;

    before(function(done) {
      Physician = db.define('Physician', {name: String});
      Patient = db.define('Patient', {name: String, age: Number, realm: String,
        sequence: {type: Number, index: true}});
      Appointment = db.define('Appointment', {date: {type: Date,
        default: function() {
          return new Date();
        }}});
      Address = db.define('Address', {name: String});

      Physician.hasMany(Patient, {through: Appointment});
      Patient.hasMany(Physician, {through: Appointment});
      Patient.belongsTo(Address);
      Appointment.belongsTo(Patient);
      Appointment.belongsTo(Physician);

      db.automigrate(['Physician', 'Patient', 'Appointment', 'Address'], done);
    });

    it('should build record on scope', function(done) {
      Physician.create(function(err, physician) {
        const patient = physician.patients.build();
        patient.physicianId.should.eql(physician.id);
        patient.save(done);
      });
    });

    it('should create record on scope', function(done) {
      Physician.create(function(err, physician) {
        physician.patients.create(function(err, patient) {
          if (err) return done(err);
          should.exist(patient);
          Appointment.find({where: {physicianId: physician.id, patientId: patient.id}},
            function(err, apps) {
              if (err) return done(err);
              apps.should.have.lengthOf(1);
              done();
            });
        });
      });
    });

    it('should create record on scope with promises', function(done) {
      Physician.create()
        .then(function(physician) {
          return physician.patients.create()
            .then(function(patient) {
              should.exist(patient);
              return Appointment.find({where: {physicianId: physician.id, patientId: patient.id}})
                .then(function(apps) {
                  apps.should.have.lengthOf(1);
                  done();
                });
            });
        }).catch(done);
    });

    it('should create multiple records on scope', function(done) {
      const async = require('async');
      Physician.create(function(err, physician) {
        physician.patients.create([{}, {}], function(err, patients) {
          if (err) return done(err);
          should.exist(patients);
          patients.should.have.lengthOf(2);
          function verifyPatient(patient, next) {
            Appointment.find({where: {
              physicianId: physician.id,
              patientId: patient.id,
            }},
            function(err, apps) {
              if (err) return done(err);
              apps.should.have.lengthOf(1);
              next();
            });
          }
          async.forEach(patients, verifyPatient, done);
        });
      });
    });

    it('should create multiple records on scope with promises', function(done) {
      const async = require('async');
      Physician.create()
        .then(function(physician) {
          return physician.patients.create([{}, {}])
            .then(function(patients) {
              should.exist(patients);
              patients.should.have.lengthOf(2);
              function verifyPatient(patient, next) {
                Appointment.find({where: {
                  physicianId: physician.id,
                  patientId: patient.id,
                }})
                  .then(function(apps) {
                    apps.should.have.lengthOf(1);
                    next();
                  });
              }
              async.forEach(patients, verifyPatient, done);
            });
        }).catch(done);
    });

    it('should fetch all scoped instances', function(done) {
      Physician.create(function(err, physician) {
        physician.patients.create({name: 'a'}, function() {
          physician.patients.create({name: 'z'}, function() {
            physician.patients.create({name: 'c'}, function() {
              verify(physician);
            });
          });
        });
      });
      function verify(physician) {
        physician.patients(function(err, ch) {
          const patients = physician.patients();
          patients.should.eql(ch);

          if (err) return done(err);
          should.exist(ch);
          ch.should.have.lengthOf(3);
          done();
        });
      }
    });

    it('should fetch all scoped instances with promises', function(done) {
      Physician.create()
        .then(function(physician) {
          return physician.patients.create({name: 'a'})
            .then(function() {
              return physician.patients.create({name: 'z'});
            })
            .then(function() {
              return physician.patients.create({name: 'c'});
            })
            .then(function() {
              return verify(physician);
            });
        }).catch(done);
      function verify(physician) {
        return physician.patients.find()
          .then(function(ch) {
            const patients = physician.patients();
            should.equal(patients, ch);

            should.exist(ch);
            ch.should.have.lengthOf(3);
            done();
          });
      }
    });

    describe('fetch scoped instances with paging filters', function() {
      let samplePatientId;
      let physician;

      beforeEach(createSampleData);

      context('with filter skip', function() {
        bdd.itIf(connectorCapabilities.supportPagination !== false,
          'skips the first patient', function(done) {
            physician.patients({skip: 1, order: 'sequence'}, function(err, ch) {
              if (err) return done(err);
              should.exist(ch);
              ch.should.have.lengthOf(2);
              ch[0].name.should.eql('z');
              ch[1].name.should.eql('c');
              done();
            });
          });
      });
      context('with filter order', function() {
        it('orders the result by patient name', function(done) {
          const filter = connectorCapabilities.adhocSort !== false ? {order: 'name DESC'} : {};
          physician.patients(filter, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(3);
            if (connectorCapabilities.adhocSort !== false) {
              ch[0].name.should.eql('z');
              ch[1].name.should.eql('c');
              ch[2].name.should.eql('a');
            } else {
              const acz = ['a', 'c', 'z'];
              ch[0].name.should.be.oneOf(acz);
              ch[1].name.should.be.oneOf(acz);
              ch[2].name.should.be.oneOf(acz);
            }
            done();
          });
        });
      });
      context('with filter limit', function() {
        it('limits to 1 result', function(done) {
          physician.patients({limit: 1, order: 'sequence'}, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(1);
            if (connectorCapabilities.adhocSort !== false) {
              ch[0].name.should.eql('a');
            } else {
              ch[0].name.should.be.oneOf(['a', 'c', 'z']);
            }
            done();
          });
        });
      });
      context('with filter fields', function() {
        it('includes field \'name\' but not \'age\'', function(done) {
          const fieldsFilter = {
            fields: {name: true, age: false},
            order: 'sequence',
          };
          physician.patients(fieldsFilter, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            should.exist(ch[0].name);
            if (connectorCapabilities.adhocSort !== false) {
              ch[0].name.should.eql('a');
            } else {
              ch[0].name.should.be.oneOf(['a', 'c', 'z']);
            }
            should.not.exist(ch[0].age);
            done();
          });
        });
      });
      context('with filter include', function() {
        it('returns physicians included in patient', function(done) {
          const includeFilter = {include: 'physicians'};
          physician.patients(includeFilter, function(err, ch) {
            if (err) return done(err);
            ch.should.have.lengthOf(3);
            should.exist(ch[0].physicians);
            done();
          });
        });
      });
      context('with filter where', function() {
        it('returns patient where id equal to samplePatientId', function(done) {
          const whereFilter = {where: {id: samplePatientId}};
          physician.patients(whereFilter, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(1);
            ch[0].id.should.eql(samplePatientId);
            done();
          });
        });
        it('returns patient where name equal to samplePatient name', function(done) {
          const whereFilter = {where: {name: 'a'}};
          physician.patients(whereFilter, function(err, ch) {
            if (err) return done(err);
            should.exist(ch);
            ch.should.have.lengthOf(1);
            ch[0].name.should.eql('a');
            done();
          });
        });
        it('returns patients where id in an array', function(done) {
          const idArr = [];
          let whereFilter;
          physician.patients.create({name: 'b'}, function(err, p) {
            idArr.push(samplePatientId, p.id);
            whereFilter = {where: {id: {inq: idArr}}};
            physician.patients(whereFilter, function(err, ch) {
              if (err) return done(err);
              should.exist(ch);
              ch.should.have.lengthOf(2);
              if (typeof idArr[0] === 'object') {
                // mongodb returns `id` as an object
                idArr[0] = idArr[0].toString();
                idArr[1] = idArr[1].toString();
                idArr.indexOf(ch[0].id.toString()).should.not.equal(-1);
                idArr.indexOf(ch[1].id.toString()).should.not.equal(-1);
              } else {
                idArr.indexOf(ch[0].id).should.not.equal(-1);
                idArr.indexOf(ch[1].id).should.not.equal(-1);
              }
              done();
            });
          });
        });
        it('returns empty result when patientId does not belongs to physician', function(done) {
          Patient.create({name: 'x'}, function(err, p) {
            if (err) return done(err);
            should.exist(p);

            const wrongWhereFilter = {where: {id: p.id}};
            physician.patients(wrongWhereFilter, function(err, ch) {
              if (err) return done(err);
              should.exist(ch);
              ch.should.have.lengthOf(0);
              done();
            });
          });
        });
      });
      context('findById with filter include', function() {
        it('returns patient where id equal to \'samplePatientId\'' +
          'with included physicians', function(done) {
          const includeFilter = {include: 'physicians'};
          physician.patients.findById(samplePatientId,
            includeFilter, function(err, ch) {
              if (err) return done(err);
              should.exist(ch);
              ch.id.should.eql(samplePatientId);
              should.exist(ch.physicians);
              done();
            });
        });
      });
      context('findById with filter fields', function() {
        it('returns patient where id equal to \'samplePatientId\'' +
          'with field \'name\' but not \'age\'', function(done) {
          const fieldsFilter = {fields: {name: true, age: false}};
          physician.patients.findById(samplePatientId,
            fieldsFilter, function(err, ch) {
              if (err) return done(err);
              should.exist(ch);
              should.exist(ch.name);
              ch.name.should.eql('a');
              should.not.exist(ch.age);
              done();
            });
        });
      });
      context('findById with include filter that contains string fields', function() {
        it('should accept string and convert it to array', function(done) {
          const includeFilter = {include: {relation: 'patients', scope: {fields: 'name'}}};
          const physicianId = physician.id;
          Physician.findById(physicianId, includeFilter, function(err, result) {
            if (err) return done(err);
            should.exist(result);
            result.id.should.eql(physicianId);
            should.exist(result.patients);
            result.patients().should.be.an.instanceOf(Array);
            should.exist(result.patients()[0]);
            should.exist(result.patients()[0].name);
            should.not.exist(result.patients()[0].age);
            done();
          });
        });
      });

      function createSampleData(done) {
        Physician.create(function(err, result) {
          result.patients.create({name: 'a', age: '10', sequence: 1},
            function(err, p) {
              samplePatientId = p.id;
              result.patients.create({name: 'z', age: '20', sequence: 2},
                function() {
                  result.patients.create({name: 'c', sequence: 3}, function() {
                    physician = result;
                    done();
                  });
                });
            });
        });
      }
    });

    describe('find over related model with options', function() {
      after(function() {
        Physician.clearObservers('access');
        Patient.clearObservers('access');
      });
      before(function() {
        Physician.observe('access', beforeAccessFn);
        Patient.observe('access', beforeAccessFn);

        function beforeAccessFn(ctx, next) {
          ctx.query.where.realm = ctx.options.realm;
          next();
        }
      });
      it('should find be filtered from option', function(done) {
        let id;
        Physician.create(function(err, physician) {
          if (err) return done(err);
          physician.patients.create({name: 'a', realm: 'test'}, function(err, ch) {
            if (err) return done(err);
            id = ch.id;
            physician.patients.create({name: 'z', realm: 'test'}, function(err) {
              if (err) return done(err);
              physician.patients.create({name: 'c', realm: 'anotherRealm'}, function(err) {
                if (err) return done(err);
                verify(physician);
              });
            });
          });
        });

        function verify(physician) {
          physician.patients({order: 'name ASC'}, {realm: 'test'}, function(err, records) {
            if (err) return done(err);
            should.exist(records);
            records.length.should.eql(2);
            const expected = ['a:test', 'z:test'];
            const actual = records.map(function(r) { return r.name + ':' + r.realm; });
            actual.sort().should.eql(expected.sort());
            done();
          });
        }
      });
    });

    it('should find scoped record', function(done) {
      let id;
      Physician.create(function(err, physician) {
        physician.patients.create({name: 'a'}, function(err, ch) {
          id = ch.id;
          physician.patients.create({name: 'z'}, function() {
            physician.patients.create({name: 'c'}, function() {
              verify(physician);
            });
          });
        });
      });

      function verify(physician) {
        physician.patients.findById(id, function(err, ch) {
          if (err) return done(err);
          should.exist(ch);
          ch.id.should.eql(id);
          done();
        });
      }
    });

    it('should find scoped record with promises', function(done) {
      let id;
      Physician.create()
        .then(function(physician) {
          return physician.patients.create({name: 'a'})
            .then(function(ch) {
              id = ch.id;
              return physician.patients.create({name: 'z'});
            })
            .then(function() {
              return physician.patients.create({name: 'c'});
            })
            .then(function() {
              return verify(physician);
            });
        }).catch(done);

      function verify(physician) {
        return physician.patients.findById(id, function(err, ch) {
          if (err) return done(err);
          should.exist(ch);
          ch.id.should.eql(id);
          done();
        });
      }
    });

    it('should allow to use include syntax on related data', function(done) {
      Physician.create(function(err, physician) {
        physician.patients.create({name: 'a'}, function(err, patient) {
          Address.create({name: 'z'}, function(err, address) {
            if (err) return done(err);
            patient.address(address);
            patient.save(function() {
              verify(physician, address.id);
            });
          });
        });
      });
      function verify(physician, addressId) {
        physician.patients({include: 'address'}, function(err, ch) {
          if (err) return done(err);
          should.exist(ch);
          ch.should.have.lengthOf(1);
          ch[0].addressId.should.eql(addressId);
          const address = ch[0].address();
          should.exist(address);
          address.should.be.an.instanceof(Address);
          address.name.should.equal('z');
          done();
        });
      }
    });

    it('should allow to use include syntax on related data with promises', function(done) {
      Physician.create()
        .then(function(physician) {
          return physician.patients.create({name: 'a'})
            .then(function(patient) {
              return Address.create({name: 'z'})
                .then(function(address) {
                  patient.address(address);
                  return patient.save()
                    .then(function() {
                      return verify(physician, address.id);
                    });
                });
            });
        }).catch(done);

      function verify(physician, addressId) {
        return physician.patients.find({include: 'address'})
          .then(function(ch) {
            should.exist(ch);
            ch.should.have.lengthOf(1);
            ch[0].addressId.toString().should.eql(addressId.toString());
            const address = ch[0].address();
            should.exist(address);
            address.should.be.an.instanceof(Address);
            address.name.should.equal('z');
            done();
          });
      }
    });

    it('should set targetClass on scope property', function() {
      should.equal(Physician.prototype.patients._targetClass, 'Patient');
    });

    it('should update scoped record', function(done) {
      let id;
      Physician.create(function(err, physician) {
        physician.patients.create({name: 'a'}, function(err, ch) {
          id = ch.id;
          physician.patients.updateById(id, {name: 'aa'}, function(err, ch) {
            verify(physician);
          });
        });
      });

      function verify(physician) {
        physician.patients.findById(id, function(err, ch) {
          if (err) return done(err);
          should.exist(ch);
          ch.id.should.eql(id);
          ch.name.should.equal('aa');
          done();
        });
      }
    });

    it('should update scoped record with promises', function(done) {
      let id;
      Physician.create()
        .then(function(physician) {
          return physician.patients.create({name: 'a'})
            .then(function(ch) {
              id = ch.id;
              return physician.patients.updateById(id, {name: 'aa'})
                .then(function(ch) {
                  return verify(physician);
                });
            });
        }).catch(done);

      function verify(physician) {
        return physician.patients.findById(id)
          .then(function(ch) {
            should.exist(ch);
            ch.id.should.eql(id);
            ch.name.should.equal('aa');
            done();
          });
      }
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should destroy scoped record', function(done) {
        let id;
        Physician.create(function(err, physician) {
          physician.patients.create({name: 'a'}, function(err, ch) {
            id = ch.id;
            physician.patients.destroy(id, function(err, ch) {
              verify(physician);
            });
          });
        });

        function verify(physician) {
          physician.patients.findById(id, function(err, ch) {
            should.exist(err);
            done();
          });
        }
      });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should destroy scoped record with promises', function(done) {
        let id;
        Physician.create()
          .then(function(physician) {
            return physician.patients.create({name: 'a'})
              .then(function(ch) {
                id = ch.id;
                return physician.patients.destroy(id)
                  .then(function(ch) {
                    return verify(physician);
                  });
              });
          }).catch(done);

        function verify(physician) {
          return physician.patients.findById(id)
            .then(function(ch) {
              should.not.exist(ch);
              done();
            })
            .catch(function(err) {
              should.exist(err);
              done();
            });
        }
      });

    it('should check existence of a scoped record', function(done) {
      let id;
      Physician.create(function(err, physician) {
        physician.patients.create({name: 'a'}, function(err, ch) {
          if (err) return done(err);
          id = ch.id;
          physician.patients.create({name: 'z'}, function() {
            physician.patients.create({name: 'c'}, function() {
              verify(physician);
            });
          });
        });
      });

      function verify(physician) {
        physician.patients.exists(id, function(err, flag) {
          if (err) return done(err);
          flag.should.be.eql(true);
          done();
        });
      }
    });

    it('should check existence of a scoped record with promises', function(done) {
      let id;
      Physician.create()
        .then(function(physician) {
          return physician.patients.create({name: 'a'})
            .then(function(ch) {
              id = ch.id;
              return physician.patients.create({name: 'z'});
            })
            .then(function() {
              return physician.patients.create({name: 'c'});
            })
            .then(function() {
              return verify(physician);
            });
        }).catch(done);

      function verify(physician) {
        return physician.patients.exists(id)
          .then(function(flag) {
            flag.should.be.eql(true);
            done();
          });
      }
    });

    it('should allow to add connection with instance', function(done) {
      Physician.create({name: 'ph1'}, function(e, physician) {
        Patient.create({name: 'pa1'}, function(e, patient) {
          physician.patients.add(patient, function(e, app) {
            should.not.exist(e);
            should.exist(app);
            app.should.be.an.instanceOf(Appointment);
            app.physicianId.should.eql(physician.id);
            app.patientId.should.eql(patient.id);
            done();
          });
        });
      });
    });

    it('should allow to add connection with instance with promises', function(done) {
      Physician.create({name: 'ph1'})
        .then(function(physician) {
          return Patient.create({name: 'pa1'})
            .then(function(patient) {
              return physician.patients.add(patient)
                .then(function(app) {
                  should.exist(app);
                  app.should.be.an.instanceOf(Appointment);
                  app.physicianId.should.eql(physician.id);
                  app.patientId.should.eql(patient.id);
                  done();
                });
            });
        }).catch(done);
    });

    it('should allow to add connection with through data', function(done) {
      Physician.create({name: 'ph1'}, function(e, physician) {
        Patient.create({name: 'pa1'}, function(e, patient) {
          const now = Date.now();
          physician.patients.add(patient, {date: new Date(now)}, function(e, app) {
            should.not.exist(e);
            should.exist(app);
            app.should.be.an.instanceOf(Appointment);
            app.physicianId.should.eql(physician.id);
            app.patientId.should.eql(patient.id);
            app.patientId.should.eql(patient.id);
            app.date.getTime().should.equal(now);
            done();
          });
        });
      });
    });

    it('should allow to add connection with through data with promises', function(done) {
      Physician.create({name: 'ph1'})
        .then(function(physician) {
          return Patient.create({name: 'pa1'})
            .then(function(patient) {
              const now = Date.now();
              return physician.patients.add(patient, {date: new Date(now)})
                .then(function(app) {
                  should.exist(app);
                  app.should.be.an.instanceOf(Appointment);
                  app.physicianId.should.eql(physician.id);
                  app.patientId.should.eql(patient.id);
                  app.patientId.should.eql(patient.id);
                  app.date.getTime().should.equal(now);
                  done();
                });
            });
        }).catch(done);
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should allow to remove connection with instance', function(done) {
        let id;
        Physician.create(function(err, physician) {
          physician.patients.create({name: 'a'}, function(err, patient) {
            id = patient.id;
            physician.patients.remove(id, function(err, ch) {
              verify(physician);
            });
          });
        });

        function verify(physician) {
          physician.patients.exists(id, function(err, flag) {
            if (err) return done(err);
            flag.should.be.eql(false);
            done();
          });
        }
      });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should allow to remove connection with instance with promises', function(done) {
        let id;
        Physician.create()
          .then(function(physician) {
            return physician.patients.create({name: 'a'})
              .then(function(patient) {
                id = patient.id;
                return physician.patients.remove(id)
                  .then(function(ch) {
                    return verify(physician);
                  });
              });
          }).catch(done);

        function verify(physician) {
          return physician.patients.exists(id)
            .then(function(flag) {
              flag.should.be.eql(false);
              done();
            });
        }
      });

    beforeEach(function(done) {
      Appointment.destroyAll(function(err) {
        Physician.destroyAll(function(err) {
          Patient.destroyAll(done);
        });
      });
    });
  });

  describe('hasMany through - collect', function() {
    let Physician, Patient, Appointment, Address;
    let idPatient, idPhysician;

    beforeEach(function(done) {
      idPatient = uid.fromConnector(db) || 1234;
      idPhysician = uid.fromConnector(db) || 2345;
      Physician = db.define('Physician', {name: String});
      Patient = db.define('Patient', {name: String});
      Appointment = db.define('Appointment', {date: {type: Date,
        default: function() {
          return new Date();
        }}});
      Address = db.define('Address', {name: String});

      db.automigrate(['Physician', 'Patient', 'Appointment', 'Address'], done);
    });

    describe('with default options', function() {
      it('can determine the collect by modelTo\'s name as default', function() {
        Physician.hasMany(Patient, {through: Appointment});
        Patient.hasMany(Physician, {through: Appointment, as: 'yyy'});
        Patient.belongsTo(Address);
        Appointment.belongsTo(Physician);
        Appointment.belongsTo(Patient);
        const physician = new Physician({id: idPhysician});
        const scope1 = physician.patients._scope;
        scope1.should.have.property('collect', 'patient');
        scope1.should.have.property('include', 'patient');
        const patient = new Patient({id: idPatient});
        const scope2 = patient.yyy._scope;
        scope2.should.have.property('collect', 'physician');
        scope2.should.have.property('include', 'physician');
      });
    });

    describe('when custom reverse belongsTo names for both sides', function() {
      it('can determine the collect via keyThrough', function() {
        Physician.hasMany(Patient, {
          through: Appointment, foreignKey: 'fooId', keyThrough: 'barId',
        });
        Patient.hasMany(Physician, {
          through: Appointment, foreignKey: 'barId', keyThrough: 'fooId', as: 'yyy',
        });
        Appointment.belongsTo(Physician, {as: 'foo'});
        Appointment.belongsTo(Patient, {as: 'bar'});
        Patient.belongsTo(Address); // jam.
        Appointment.belongsTo(Patient, {as: 'car'}); // jam. Should we complain in this case???

        const physician = new Physician({id: idPhysician});
        const scope1 = physician.patients._scope;
        scope1.should.have.property('collect', 'bar');
        scope1.should.have.property('include', 'bar');
        const patient = new Patient({id: idPatient});
        const scope2 = patient.yyy._scope;
        scope2.should.have.property('collect', 'foo');
        scope2.should.have.property('include', 'foo');
      });

      it('can determine the collect via modelTo name', function() {
        Physician.hasMany(Patient, {through: Appointment});
        Patient.hasMany(Physician, {through: Appointment, as: 'yyy'});
        Appointment.belongsTo(Physician, {as: 'foo', foreignKey: 'physicianId'});
        Appointment.belongsTo(Patient, {as: 'bar', foreignKey: 'patientId'});
        Patient.belongsTo(Address); // jam.

        const physician = new Physician({id: idPhysician});
        const scope1 = physician.patients._scope;
        scope1.should.have.property('collect', 'bar');
        scope1.should.have.property('include', 'bar');
        const patient = new Patient({id: idPatient});
        const scope2 = patient.yyy._scope;
        scope2.should.have.property('collect', 'foo');
        scope2.should.have.property('include', 'foo');
      });

      it('can determine the collect via modelTo name (with jams)', function() {
        Physician.hasMany(Patient, {through: Appointment});
        Patient.hasMany(Physician, {through: Appointment, as: 'yyy'});
        Appointment.belongsTo(Physician, {as: 'foo', foreignKey: 'physicianId'});
        Appointment.belongsTo(Patient, {as: 'bar', foreignKey: 'patientId'});
        Patient.belongsTo(Address); // jam.
        Appointment.belongsTo(Physician, {as: 'goo', foreignKey: 'physicianId'}); // jam. Should we complain in this case???
        Appointment.belongsTo(Patient, {as: 'car', foreignKey: 'patientId'}); // jam. Should we complain in this case???

        const physician = new Physician({id: idPhysician});
        const scope1 = physician.patients._scope;
        scope1.should.have.property('collect', 'bar');
        scope1.should.have.property('include', 'bar');
        const patient = new Patient({id: idPatient});
        const scope2 = patient.yyy._scope;
        scope2.should.have.property('collect', 'foo'); // first matched relation
        scope2.should.have.property('include', 'foo'); // first matched relation
      });
    });

    describe('when custom reverse belongsTo name for one side only', function() {
      beforeEach(function() {
        Physician.hasMany(Patient, {as: 'xxx', through: Appointment, foreignKey: 'fooId'});
        Patient.hasMany(Physician, {as: 'yyy', through: Appointment, keyThrough: 'fooId'});
        Appointment.belongsTo(Physician, {as: 'foo'});
        Appointment.belongsTo(Patient);
        Patient.belongsTo(Address); // jam.
        Appointment.belongsTo(Physician, {as: 'bar'}); // jam. Should we complain in this case???
      });

      it('can determine the collect via model name', function() {
        const physician = new Physician({id: idPhysician});
        const scope1 = physician.xxx._scope;
        scope1.should.have.property('collect', 'patient');
        scope1.should.have.property('include', 'patient');
      });

      it('can determine the collect via keyThrough', function() {
        const patient = new Patient({id: idPatient});
        const scope2 = patient.yyy._scope;
        scope2.should.have.property('collect', 'foo');
        scope2.should.have.property('include', 'foo');
      });
    });
  });

  describe('hasMany through - customized relation name and foreign key', function() {
    let Physician, Patient, Appointment;

    beforeEach(function(done) {
      Physician = db.define('Physician', {name: String});
      Patient = db.define('Patient', {name: String});
      Appointment = db.define('Appointment', {date: {type: Date, defaultFn: 'now'}});

      db.automigrate(['Physician', 'Patient', 'Appointment'], done);
    });

    it('should use real target class', function() {
      Physician.hasMany(Patient, {through: Appointment, as: 'xxx', foreignKey: 'aaaId', keyThrough: 'bbbId'});
      Patient.hasMany(Physician, {through: Appointment, as: 'yyy', foreignKey: 'bbbId', keyThrough: 'aaaId'});
      Appointment.belongsTo(Physician, {as: 'aaa', foreignKey: 'aaaId'});
      Appointment.belongsTo(Patient, {as: 'bbb', foreignKey: 'bbbId'});
      const physician = new Physician({id: 1});
      physician.xxx.should.have.property('_targetClass', 'Patient');
      const patient = new Patient({id: 1});
      patient.yyy.should.have.property('_targetClass', 'Physician');
    });
  });

  describe('hasMany through bi-directional relations on the same model', function() {
    let User, Follow, Address;
    let idFollower, idFollowee;

    before(function(done) {
      idFollower = uid.fromConnector(db) || 3456;
      idFollowee = uid.fromConnector(db) || 4567;
      User = db.define('User', {name: String});
      Follow = db.define('Follow', {date: {type: Date,
        default: function() {
          return new Date();
        }}});
      Address = db.define('Address', {name: String});

      User.hasMany(User, {
        as: 'followers', foreignKey: 'followeeId', keyThrough: 'followerId', through: Follow,
      });
      User.hasMany(User, {
        as: 'following', foreignKey: 'followerId', keyThrough: 'followeeId', through: Follow,
      });
      User.belongsTo(Address);
      Follow.belongsTo(User, {as: 'follower'});
      Follow.belongsTo(User, {as: 'followee'});
      db.automigrate(['User', 'Follow'], done);
    });

    it('should set foreignKeys of through model correctly in first relation',
      function(done) {
        const follower = new User({id: idFollower});
        const followee = new User({id: idFollowee});
        followee.followers.add(follower, function(err, throughInst) {
          if (err) return done(err);
          should.exist(throughInst);
          throughInst.followerId.should.eql(follower.id);
          throughInst.followeeId.should.eql(followee.id);
          done();
        });
      });

    it('should set foreignKeys of through model correctly in second relation',
      function(done) {
        const follower = new User({id: idFollower});
        const followee = new User({id: idFollowee});
        follower.following.add(followee, function(err, throughInst) {
          if (err) return done(err);
          should.exist(throughInst);
          throughInst.followeeId.toString().should.eql(followee.id.toString());
          throughInst.followerId.toString().should.eql(follower.id.toString());
          done();
        });
      });
  });

  describe('hasMany through - between same models', function() {
    let User, Follow, Address;
    let idFollower, idFollowee;

    before(function(done) {
      idFollower = uid.fromConnector(db) || 3456;
      idFollowee = uid.fromConnector(db) || 4567;
      User = db.define('User', {name: String});
      Follow = db.define('Follow', {date: {type: Date,
        default: function() {
          return new Date();
        }}});
      Address = db.define('Address', {name: String});

      User.hasMany(User, {
        as: 'followers', foreignKey: 'followeeId', keyThrough: 'followerId', through: Follow,
      });
      User.hasMany(User, {
        as: 'following', foreignKey: 'followerId', keyThrough: 'followeeId', through: Follow,
      });
      User.belongsTo(Address);
      Follow.belongsTo(User, {as: 'follower'});
      Follow.belongsTo(User, {as: 'followee'});
      db.automigrate(['User', 'Follow', 'Address'], done);
    });

    it('should set the keyThrough and the foreignKey', function(done) {
      const user = new User({id: idFollower});
      const user2 = new User({id: idFollowee});
      user.following.add(user2, function(err, f) {
        if (err) return done(err);
        should.exist(f);
        f.followeeId.should.eql(user2.id);
        f.followerId.should.eql(user.id);
        done();
      });
    });

    it('can determine the collect via keyThrough for each side', function() {
      const user = new User({id: idFollower});
      const scope1 = user.followers._scope;
      scope1.should.have.property('collect', 'follower');
      scope1.should.have.property('include', 'follower');
      const scope2 = user.following._scope;
      scope2.should.have.property('collect', 'followee');
      scope2.should.have.property('include', 'followee');
    });
  });

  describe('hasMany with properties', function() {
    before(function(done) {
      Book = db.define('Book', {name: String, type: String});
      Chapter = db.define('Chapter', {name: {type: String, index: true},
        bookType: String});
      Book.hasMany(Chapter, {properties: {type: 'bookType'}});
      db.automigrate(['Book', 'Chapter'], done);
    });

    it('should create record on scope', function(done) {
      Book.create({type: 'fiction'}, function(err, book) {
        book.chapters.create(function(err, c) {
          if (err) return done(err);
          should.exist(c);
          c.bookId.should.eql(book.id);
          c.bookType.should.equal('fiction');
          done();
        });
      });
    });

    it('should create record on scope with promises', function(done) {
      Book.create({type: 'fiction'})
        .then(function(book) {
          return book.chapters.create()
            .then(function(c) {
              should.exist(c);
              c.bookId.should.eql(book.id);
              c.bookType.should.equal('fiction');
              done();
            });
        }).catch(done);
    });
  });

  describe('hasMany with scope and properties', function() {
    it('can be declared with properties', function(done) {
      Category = db.define('Category', {name: String, jobType: String});
      Job = db.define('Job', {name: String, type: String});

      Category.hasMany(Job, {
        properties: function(inst, target) {
          if (!inst.jobType) return; // skip
          return {type: inst.jobType};
        },
        scope: function(inst, filter) {
          const m = this.properties(inst); // re-use properties
          if (m) return {where: m};
        },
      });
      db.automigrate(['Category', 'Job'], done);
    });

    it('should create record on scope', function(done) {
      Category.create(function(err, c) {
        should.not.exists(err);
        c.jobs.create({type: 'book'}, function(err, p) {
          should.not.exists(err);
          p.categoryId.should.eql(c.id);
          p.type.should.equal('book');
          c.jobs.create({type: 'widget'}, function(err, p) {
            should.not.exists(err);
            p.categoryId.should.eql(c.id);
            p.type.should.equal('widget');
            done();
          });
        });
      });
    });

    it('should create record on scope with promises', function(done) {
      Category.create()
        .then(function(c) {
          return c.jobs.create({type: 'book'})
            .then(function(p) {
              p.categoryId.should.eql(c.id);
              p.type.should.equal('book');
              return c.jobs.create({type: 'widget'})
                .then(function(p) {
                  p.categoryId.should.eql(c.id);
                  p.type.should.equal('widget');
                  done();
                });
            });
        }).catch(done);
    });

    it('should find records on scope', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobs(function(err, jobs) {
          should.not.exists(err);
          jobs.should.have.length(2);
          done();
        });
      });
    });

    it('should find records on scope with promises', function(done) {
      Category.findOne()
        .then(function(c) {
          return c.jobs.find();
        })
        .then(function(jobs) {
          jobs.should.have.length(2);
          done();
        })
        .catch(done);
    });

    it('should find record on scope - filtered', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobs({where: {type: 'book'}}, function(err, jobs) {
          should.not.exists(err);
          jobs.should.have.length(1);
          jobs[0].type.should.equal('book');
          done();
        });
      });
    });

    it('should find record on scope with promises - filtered', function(done) {
      Category.findOne()
        .then(function(c) {
          return c.jobs.find({where: {type: 'book'}});
        })
        .then(function(jobs) {
          jobs.should.have.length(1);
          jobs[0].type.should.equal('book');
          done();
        })
        .catch(done);
    });

    // So why not just do the above? In LoopBack, the context
    // that gets passed into a beforeRemote handler contains
    // a reference to the parent scope/instance: ctx.instance
    // in order to enforce a (dynamic scope) at runtime
    // a temporary property can be set in the beforeRemoting
    // handler. Optionally,properties dynamic properties can be declared.
    //
    // The code below simulates this.

    it('should create record on scope - properties', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobType = 'tool'; // temporary
        c.jobs.create(function(err, p) {
          p.categoryId.should.eql(c.id);
          p.type.should.equal('tool');
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find records on scope', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobs(function(err, jobs) {
          should.not.exists(err);
          jobs.should.have.length(3);
          done();
        });
      });
    });

    it('should find record on scope - scoped', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobType = 'book'; // temporary, for scoping
        c.jobs(function(err, jobs) {
          should.not.exists(err);
          jobs.should.have.length(1);
          jobs[0].type.should.equal('book');
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find record on scope - scoped', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobType = 'tool'; // temporary, for scoping
        c.jobs(function(err, jobs) {
          should.not.exists(err);
          jobs.should.have.length(1);
          jobs[0].type.should.equal('tool');
          done();
        });
      });
    });

    it('should find count of records on scope - scoped', function(done) {
      Category.findOne(function(err, c) {
        should.not.exists(err);
        c.jobType = 'tool'; // temporary, for scoping
        c.jobs.count(function(err, count) {
          should.not.exists(err);
          count.should.equal(1);
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should delete records on scope - scoped', function(done) {
        Category.findOne(function(err, c) {
          should.not.exists(err);
          c.jobType = 'tool'; // temporary, for scoping
          c.jobs.destroyAll(function(err, result) {
            done(err);
          });
        });
      });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should find record on scope - verify', function(done) {
        Category.findOne(function(err, c) {
          should.not.exists(err);
          c.jobs(function(err, jobs) {
            should.not.exists(err);
            jobs.should.have.length(2);
            done(err);
          });
        });
      });
  });

  describe('relations validation', function() {
    let validationError;
    // define a mockup getRelationValidationMsg() method to log the validation error
    const logRelationValidationError = function(code, rType, rName) {
      validationError = {code, rType, rName};
    };

    it('rejects belongsTo relation if `model` is not provided', function() {
      try {
        const Picture = db.define('Picture', {name: String}, {relations: {
          author: {
            type: 'belongsTo',
            foreignKey: 'authorId'},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'BELONGS_TO_MISSING_MODEL',
          rType: 'belongsTo',
          rName: 'author'});
      }
    });

    it('rejects polymorphic belongsTo relation if `model` is provided', function() {
      try {
        const Picture = db.define('Picture', {name: String}, {relations: {
          imageable: {
            type: 'belongsTo',
            model: 'Picture',
            polymorphic: true},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'POLYMORPHIC_BELONGS_TO_MODEL',
          rType: 'belongsTo',
          rName: 'imageable'});
      }
    });

    it('rejects polymorphic non belongsTo relation if `model` is not provided', function() {
      try {
        const Article = db.define('Picture', {name: String}, {relations: {
          pictures: {
            type: 'hasMany',
            polymorphic: 'imageable'},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'POLYMORPHIC_NOT_BELONGS_TO_MISSING_MODEL',
          rType: 'hasMany',
          rName: 'pictures'});
      }
    });

    it('rejects polymorphic relation if `foreignKey` is provided but discriminator ' +
    'is missing', function() {
      try {
        const Article = db.define('Picture', {name: String}, {relations: {
          pictures: {
            type: 'hasMany',
            model: 'Picture',
            polymorphic: {foreignKey: 'imageableId'}},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'POLYMORPHIC_MISSING_DISCRIMINATOR',
          rType: 'hasMany',
          rName: 'pictures'});
      }
    });

    it('rejects polymorphic relation if `discriminator` is provided but foreignKey ' +
    'is missing', function() {
      try {
        const Article = db.define('Picture', {name: String}, {relations: {
          pictures: {
            type: 'hasMany',
            model: 'Picture',
            polymorphic: {discriminator: 'imageableType'}},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'POLYMORPHIC_MISSING_FOREIGN_KEY',
          rType: 'hasMany',
          rName: 'pictures'});
      }
    });

    it('rejects polymorphic relation if `polymorphic.as` is provided along ' +
    'with custom foreignKey/discriminator', function() {
      try {
        const Article = db.define('Picture', {name: String}, {relations: {
          pictures: {
            type: 'hasMany',
            model: 'Picture',
            polymorphic: {
              as: 'image',
              foreignKey: 'imageableId',
              discriminator: 'imageableType',
            }},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'POLYMORPHIC_EXTRANEOUS_AS',
          rType: 'hasMany',
          rName: 'pictures'});
      }
    });

    it('rejects polymorphic relation if `polymorphic.selector` is provided along ' +
    'with custom foreignKey/discriminator', function() {
      try {
        const Article = db.define('Picture', {name: String}, {relations: {
          pictures: {
            type: 'hasMany',
            model: 'Picture',
            polymorphic: {
              selector: 'image',
              foreignKey: 'imageableId',
              discriminator: 'imageableType',
            }},
        }});
        should.not.exist(Picture, 'relation validation should have thrown');
      } catch (err) {
        err.details.should.eql({
          code: 'POLYMORPHIC_EXTRANEOUS_SELECTOR',
          rType: 'hasMany',
          rName: 'pictures'});
      }
    });

    it('warns on use of deprecated `polymorphic.as` keyword in polymorphic relation', function() {
      let message = 'deprecation not reported';
      process.once('deprecation', function(err) { message = err.message; });

      const Article = db.define('Picture', {name: String}, {relations: {
        pictures: {type: 'hasMany', model: 'Picture', polymorphic: {as: 'imageable'}},
      }});

      message.should.match(/keyword `polymorphic.as` which will be DEPRECATED in LoopBack.next/);
    });
  });

  describe('polymorphic hasOne', function() {
    before(function(done) {
      Picture = db.define('Picture', {name: String});
      Article = db.define('Article', {name: String});
      Employee = db.define('Employee', {name: String});

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });

    it('can be declared using default polymorphic selector', function(done) {
      Article.hasOne(Picture, {as: 'packshot', polymorphic: 'imageable'});
      Employee.hasOne(Picture, {as: 'mugshot', polymorphic: 'imageable'});
      Picture.belongsTo('imageable', {polymorphic: true});

      Article.relations['packshot'].toJSON().should.eql({
        name: 'packshot',
        type: 'hasOne',
        modelFrom: 'Article',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'imageableId',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });

      Picture.relations['imageable'].toJSON().should.eql({
        name: 'imageable',
        type: 'belongsTo',
        modelFrom: 'Picture',
        keyFrom: 'imageableId',
        modelTo: '<polymorphic>',
        keyTo: 'id',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });

    it('should create polymorphic relation - Article', function(done) {
      Article.create({name: 'Article 1'}, function(err, article) {
        should.not.exists(err);
        article.packshot.create({name: 'Packshot'}, function(err, pic) {
          if (err) return done(err);
          should.exist(pic);
          pic.imageableId.should.eql(article.id);
          pic.imageableType.should.equal('Article');
          done();
        });
      });
    });

    it('should create polymorphic relation with promises - article', function(done) {
      Article.create({name: 'Article 1'})
        .then(function(article) {
          return article.packshot.create({name: 'Packshot'})
            .then(function(pic) {
              should.exist(pic);
              pic.imageableId.should.eql(article.id);
              pic.imageableType.should.equal('Article');
              done();
            });
        }).catch(done);
    });

    it('should create polymorphic relation - reader', function(done) {
      Employee.create({name: 'Employee 1'}, function(err, employee) {
        should.not.exists(err);
        employee.mugshot.create({name: 'Mugshot'}, function(err, pic) {
          if (err) return done(err);
          should.exist(pic);
          pic.imageableId.should.eql(employee.id);
          pic.imageableType.should.equal('Employee');
          done();
        });
      });
    });

    it('should find polymorphic relation - article', function(done) {
      Article.findOne(function(err, article) {
        should.not.exists(err);
        article.packshot(function(err, pic) {
          if (err) return done(err);

          const packshot = article.packshot();
          packshot.should.equal(pic);

          pic.name.should.equal('Packshot');
          pic.imageableId.toString().should.eql(article.id.toString());
          pic.imageableType.should.equal('Article');
          done();
        });
      });
    });

    it('should find polymorphic relation - employee', function(done) {
      Employee.findOne(function(err, employee) {
        should.not.exists(err);
        employee.mugshot(function(err, mugshot) {
          if (err) return done(err);
          mugshot.name.should.equal('Mugshot');
          mugshot.imageableId.toString().should.eql(employee.id.toString());
          mugshot.imageableType.should.equal('Employee');
          done();
        });
      });
    });

    it('should include polymorphic relation - article', function(done) {
      Article.findOne({include: 'packshot'}, function(err, article) {
        should.not.exists(err);
        const packshot = article.packshot();
        should.exist(packshot);
        packshot.name.should.equal('Packshot');
        done();
      });
    });

    it('should find polymorphic relation with promises - employee', function(done) {
      Employee.findOne()
        .then(function(employee) {
          return employee.mugshot.get()
            .then(function(pic) {
              pic.name.should.equal('Mugshot');
              pic.imageableId.toString().should.eql(employee.id.toString());
              pic.imageableType.should.equal('Employee');
              done();
            });
        }).catch(done);
    });

    it('should find inverse polymorphic relation - article', function(done) {
      Picture.findOne({where: {name: 'Packshot'}}, function(err, pic) {
        should.not.exists(err);
        pic.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Article);
          imageable.name.should.equal('Article 1');
          done();
        });
      });
    });

    it('should include inverse polymorphic relation - article', function(done) {
      Picture.findOne({where: {name: 'Packshot'}, include: 'imageable'},
        function(err, pic) {
          should.not.exists(err);
          const imageable = pic.imageable();
          should.exist(imageable);
          imageable.should.be.instanceof(Article);
          imageable.name.should.equal('Article 1');
          done();
        });
    });

    it('should find inverse polymorphic relation - employee', function(done) {
      Picture.findOne({where: {name: 'Mugshot'}}, function(err, pic) {
        should.not.exists(err);
        pic.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Employee);
          imageable.name.should.equal('Employee 1');
          done();
        });
      });
    });
  });

  describe('polymorphic hasOne with non standard ids', function() {
    before(function(done) {
      Picture = db.define('Picture', {name: String});
      Article = db.define('Article', {
        username: {type: String, id: true, generated: true},
        name: String,
      });
      Employee = db.define('Employee', {
        username: {type: String, id: true, generated: true},
        name: String,
      });

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });

    it('can be declared using custom foreignKey/discriminator', function(done) {
      Article.hasOne(Picture, {
        as: 'packshot',
        polymorphic: {
          foreignKey: 'oid',
          discriminator: 'type',
        },
      });
      Employee.hasOne(Picture, {
        as: 'mugshot',
        polymorphic: {
          foreignKey: 'oid',
          discriminator: 'type',
        },
      });
      Picture.belongsTo('imageable', {
        idName: 'username',
        polymorphic: {
          idType: Article.definition.properties.username.type,
          foreignKey: 'oid',
          discriminator: 'type',
        },
      });

      Article.relations['packshot'].toJSON().should.eql({
        name: 'packshot',
        type: 'hasOne',
        modelFrom: 'Article',
        keyFrom: 'username',
        modelTo: 'Picture',
        keyTo: 'oid',
        multiple: false,
        polymorphic: {
          selector: 'packshot',
          foreignKey: 'oid',
          discriminator: 'type',
        },
      });

      const imageableRel = Picture.relations['imageable'].toJSON();

      // assert idType independantly
      assert(typeof imageableRel.polymorphic.idType == 'function');

      // backup idType and remove it temporarily from the relation
      // object to ease the test
      const idType = imageableRel.polymorphic.idType;
      delete imageableRel.polymorphic.idType;

      imageableRel.should.eql({
        name: 'imageable',
        type: 'belongsTo',
        modelFrom: 'Picture',
        keyFrom: 'oid',
        modelTo: '<polymorphic>',
        keyTo: 'username',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'oid',
          discriminator: 'type',
        },
      });

      // restore idType for next tests
      imageableRel.polymorphic.idType = idType;

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });

    it('should create polymorphic relation - article', function(done) {
      Article.create({name: 'Article 1'}, function(err, article) {
        should.not.exists(err);
        article.packshot.create({name: 'Packshot'}, function(err, pic) {
          if (err) return done(err);
          should.exist(pic);
          pic.oid.toString().should.equal(article.username.toString());
          pic.type.should.equal('Article');
          done();
        });
      });
    });

    it('should create polymorphic relation with promises - article', function(done) {
      Article.create({name: 'Article 1'})
        .then(function(article) {
          return article.packshot.create({name: 'Packshot'})
            .then(function(pic) {
              should.exist(pic);
              pic.oid.toString().should.equal(article.username.toString());
              pic.type.should.equal('Article');
              done();
            });
        }).catch(done);
    });

    it('should create polymorphic relation - employee', function(done) {
      Employee.create({name: 'Employee 1'}, function(err, employee) {
        should.not.exists(err);
        employee.mugshot.create({name: 'Mugshot'}, function(err, pic) {
          if (err) return done(err);
          should.exist(pic);
          pic.oid.toString().should.equal(employee.username.toString());
          pic.type.should.equal('Employee');
          done();
        });
      });
    });

    it('should find polymorphic relation - article', function(done) {
      Article.findOne(function(err, article) {
        should.not.exists(err);
        article.packshot(function(err, pic) {
          if (err) return done(err);

          const packshot = article.packshot();
          packshot.should.equal(pic);

          pic.name.should.equal('Packshot');
          pic.oid.toString().should.equal(article.username.toString());
          pic.type.should.equal('Article');
          done();
        });
      });
    });

    it('should find polymorphic relation - employee', function(done) {
      Employee.findOne(function(err, employee) {
        should.not.exists(err);
        employee.mugshot(function(err, pic) {
          if (err) return done(err);
          pic.name.should.equal('Mugshot');
          pic.oid.toString().should.equal(employee.username.toString());
          pic.type.should.equal('Employee');
          done();
        });
      });
    });

    it('should find inverse polymorphic relation - article', function(done) {
      Picture.findOne({where: {name: 'Packshot'}}, function(err, pic) {
        should.not.exists(err);
        pic.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Article);
          imageable.name.should.equal('Article 1');
          done();
        });
      });
    });

    it('should find inverse polymorphic relation - employee', function(done) {
      Picture.findOne({where: {name: 'Mugshot'}}, function(err, p) {
        should.not.exists(err);
        p.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Employee);
          imageable.name.should.equal('Employee 1');
          done();
        });
      });
    });

    it('should include polymorphic relation - employee', function(done) {
      Employee.findOne({include: 'mugshot'},
        function(err, employee) {
          should.not.exists(err);
          const mugshot = employee.mugshot();
          should.exist(mugshot);
          mugshot.name.should.equal('Mugshot');
          done();
        });
    });

    it('should include inverse polymorphic relation - employee', function(done) {
      Picture.findOne({where: {name: 'Mugshot'}, include: 'imageable'},
        function(err, pic) {
          should.not.exists(err);
          const imageable = pic.imageable();
          should.exist(imageable);
          imageable.should.be.instanceof(Employee);
          imageable.name.should.equal('Employee 1');
          done();
        });
    });
  });

  describe('polymorphic hasMany', function() {
    before(function(done) {
      Picture = db.define('Picture', {name: String});
      Article = db.define('Article', {name: String});
      Employee = db.define('Employee', {name: String});

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });

    it('can be declared with model JSON definition when related model is already attached', function(done) {
      const ds = new DataSource('memory');

      // by defining Picture model before Article model we make sure Picture IS
      // already attached when defining Article. This way, datasource.defineRelations
      // WILL NOT use the async listener to call hasMany relation method
      const Picture = ds.define('Picture', {name: String}, {relations: {
        imageable: {type: 'belongsTo', polymorphic: true},
      }});
      const Article = ds.define('Article', {name: String}, {relations: {
        pictures: {type: 'hasMany', model: 'Picture', polymorphic: 'imageable'},
      }});

      assert(Article.relations['pictures']);
      assert.deepEqual(Article.relations['pictures'].toJSON(), {
        name: 'pictures',
        type: 'hasMany',
        modelFrom: 'Article',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'imageableId',
        multiple: true,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });

      assert(Picture.relations['imageable']);
      assert.deepEqual(Picture.relations['imageable'].toJSON(), {
        name: 'imageable',
        type: 'belongsTo',
        modelFrom: 'Picture',
        keyFrom: 'imageableId',
        modelTo: '<polymorphic>',
        keyTo: 'id',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });
      done();
    });

    it('can be declared with model JSON definition when related model is not yet attached', function(done) {
      const ds = new DataSource('memory');

      // by defining Author model before Picture model we make sure Picture IS NOT
      // already attached when defining Author. This way, datasource.defineRelations
      // WILL use the async listener to call hasMany relation method
      const Author = ds.define('Author', {name: String}, {relations: {
        pictures: {type: 'hasMany', model: 'Picture', polymorphic: 'imageable'},
      }});
      const Picture = ds.define('Picture', {name: String}, {relations: {
        imageable: {type: 'belongsTo', polymorphic: true},
      }});

      assert(Author.relations['pictures']);
      assert.deepEqual(Author.relations['pictures'].toJSON(), {
        name: 'pictures',
        type: 'hasMany',
        modelFrom: 'Author',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'imageableId',
        multiple: true,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });

      assert(Picture.relations['imageable']);
      assert.deepEqual(Picture.relations['imageable'].toJSON(), {
        name: 'imageable',
        type: 'belongsTo',
        modelFrom: 'Picture',
        keyFrom: 'imageableId',
        modelTo: '<polymorphic>',
        keyTo: 'id',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });
      done();
    });

    it('can be declared using default polymorphic selector', function(done) {
      Article.hasMany(Picture, {polymorphic: 'imageable'});
      Employee.hasMany(Picture, {polymorphic: { // alt syntax
        foreignKey: 'imageableId',
        discriminator: 'imageableType',
      }});
      Picture.belongsTo('imageable', {polymorphic: true});

      Article.relations['pictures'].toJSON().should.eql({
        name: 'pictures',
        type: 'hasMany',
        modelFrom: 'Article',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'imageableId',
        multiple: true,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });

      Picture.relations['imageable'].toJSON().should.eql({
        name: 'imageable',
        type: 'belongsTo',
        modelFrom: 'Picture',
        keyFrom: 'imageableId',
        modelTo: '<polymorphic>',
        keyTo: 'id',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageableId',
          discriminator: 'imageableType',
        },
      });

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });

    it('should create polymorphic relation - article', function(done) {
      Article.create({name: 'Article 1'}, function(err, article) {
        should.not.exists(err);
        article.pictures.create({name: 'Article Pic'}, function(err, pics) {
          if (err) return done(err);
          should.exist(pics);
          pics.imageableId.should.eql(article.id);
          pics.imageableType.should.equal('Article');
          done();
        });
      });
    });

    it('should create polymorphic relation - employee', function(done) {
      Employee.create({name: 'Employee 1'}, function(err, employee) {
        should.not.exists(err);
        employee.pictures.create({name: 'Employee Pic'}, function(err, pics) {
          if (err) return done(err);
          should.exist(pics);
          pics.imageableId.should.eql(employee.id);
          pics.imageableType.should.equal('Employee');
          done();
        });
      });
    });

    it('should find polymorphic items - article', function(done) {
      Article.findOne(function(err, article) {
        should.not.exists(err);
        if (!article) return done();
        article.pictures(function(err, pics) {
          if (err) return done(err);

          const pictures = article.pictures();
          pictures.should.eql(pics);

          pics.should.have.length(1);
          pics[0].name.should.equal('Article Pic');
          done();
        });
      });
    });

    it('should find polymorphic items - employee', function(done) {
      Employee.findOne(function(err, employee) {
        should.not.exists(err);
        employee.pictures(function(err, pics) {
          if (err) return done(err);
          pics.should.have.length(1);
          pics[0].name.should.equal('Employee Pic');
          done();
        });
      });
    });

    it('should find the inverse of polymorphic relation - article', function(done) {
      Picture.findOne({where: {name: 'Article Pic'}}, function(err, pics) {
        if (err) return done(err);
        pics.imageableType.should.equal('Article');
        pics.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Article);
          imageable.name.should.equal('Article 1');
          done();
        });
      });
    });

    it('should find the inverse of polymorphic relation - employee', function(done) {
      Picture.findOne({where: {name: 'Employee Pic'}}, function(err, pics) {
        if (err) return done(err);
        pics.imageableType.should.equal('Employee');
        pics.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Employee);
          imageable.name.should.equal('Employee 1');
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.adhocSort !== false,
      'should include the inverse of polymorphic relation', function(done) {
        Picture.find({include: 'imageable'}, function(err, pics) {
          if (err) return done(err);
          pics.should.have.length(2);

          const actual = pics.map(
            function(pic) {
              return {imageName: pic.name, name: pic.imageable().name};
            },
          );

          actual.should.containDeep([
            {name: 'Article 1', imageName: 'Article Pic'},
            {name: 'Employee 1', imageName: 'Employee Pic'},
          ]);

          done();
        });
      });

    bdd.itIf(connectorCapabilities.adhocSort === false,
      'should include the inverse of polymorphic relation w/o adhocSort', function(done) {
        Picture.find({include: 'imageable'}, function(err, pics) {
          if (err) return done(err);
          pics.should.have.length(2);
          const names = ['Article Pic', 'Employee Pic'];
          const imageables = ['Article 1', 'Employee 1'];
          names.should.containEql(pics[0].name);
          names.should.containEql(pics[1].name);
          imageables.should.containEql(pics[0].imageable().name);
          imageables.should.containEql(pics[1].imageable().name);
          done();
        });
      });

    it('should assign a polymorphic relation', function(done) {
      Article.create({name: 'Article 2'}, function(err, article) {
        should.not.exists(err);
        const p = new Picture({name: 'Sample'});
        p.imageable(article); // assign
        p.imageableId.should.eql(article.id);
        p.imageableType.should.equal('Article');
        p.save(done);
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find polymorphic items - article', function(done) {
      Article.findOne({where: {name: 'Article 2'}}, function(err, article) {
        should.not.exists(err);
        article.pictures(function(err, pics) {
          if (err) return done(err);
          pics.should.have.length(1);
          pics[0].name.should.equal('Sample');
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find the inverse of polymorphic relation - article', function(done) {
      Picture.findOne({where: {name: 'Sample'}}, function(err, p) {
        if (err) return done(err);
        p.imageableType.should.equal('Article');
        p.imageable(function(err, imageable) {
          if (err) return done(err);
          imageable.should.be.instanceof(Article);
          imageable.name.should.equal('Article 2');
          done();
        });
      });
    });

    it('should include the inverse of polymorphic relation - article',
      function(done) {
        Picture.findOne({where: {name: 'Sample'}, include: 'imageable'},
          function(err, p) {
            if (err) return done(err);
            const imageable = p.imageable();
            should.exist(imageable);
            imageable.should.be.instanceof(Article);
            imageable.name.should.equal('Article 2');
            done();
          });
      });

    it('can be declared using custom foreignKey/discriminator', function(done) {
      Article.hasMany(Picture, {polymorphic: {
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }});
      Employee.hasMany(Picture, {polymorphic: { // alt syntax
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }});
      Picture.belongsTo('imageable', {polymorphic: {
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }});

      Article.relations['pictures'].toJSON().should.eql({
        name: 'pictures',
        type: 'hasMany',
        modelFrom: 'Article',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'imageId',
        multiple: true,
        polymorphic: {
          selector: 'pictures',
          foreignKey: 'imageId',
          discriminator: 'imageType',
        },
      });

      Picture.relations['imageable'].toJSON().should.eql({
        name: 'imageable',
        type: 'belongsTo',
        modelFrom: 'Picture',
        keyFrom: 'imageId',
        modelTo: '<polymorphic>',
        keyTo: 'id',
        multiple: false,
        polymorphic: {
          selector: 'imageable',
          foreignKey: 'imageId',
          discriminator: 'imageType',
        },
      });

      db.automigrate(['Picture', 'Article', 'Employee'], done);
    });
  });

  describe('polymorphic hasAndBelongsToMany through', function() {
    let idArticle, idEmployee;

    before(function(done) {
      idArticle = uid.fromConnector(db) || 3456;
      idEmployee = uid.fromConnector(db) || 4567;
      Picture = db.define('Picture', {name: String});
      Article = db.define('Article', {name: String});
      Employee = db.define('Employee', {name: String});
      PictureLink = db.define('PictureLink', {});

      db.automigrate(['Picture', 'Article', 'Employee', 'PictureLink'], done);
    });

    it('can be declared using default polymorphic selector', function(done) {
      Article.hasAndBelongsToMany(Picture, {through: PictureLink, polymorphic: 'imageable'});
      Employee.hasAndBelongsToMany(Picture, {through: PictureLink, polymorphic: 'imageable'});
      // Optionally, define inverse relations:
      Picture.hasMany(Article, {through: PictureLink, polymorphic: 'imageable', invert: true});
      Picture.hasMany(Employee, {through: PictureLink, polymorphic: 'imageable', invert: true});
      db.automigrate(['Picture', 'Article', 'Employee', 'PictureLink'], done);
    });

    it('can determine the collect via modelTo name', function() {
      Article.hasAndBelongsToMany(Picture, {through: PictureLink, polymorphic: 'imageable'});
      Employee.hasAndBelongsToMany(Picture, {through: PictureLink, polymorphic: 'imageable'});
      // Optionally, define inverse relations:
      Picture.hasMany(Article, {through: PictureLink, polymorphic: 'imageable', invert: true});
      Picture.hasMany(Employee, {through: PictureLink, polymorphic: 'imageable', invert: true});
      const article = new Article({id: idArticle});
      const scope1 = article.pictures._scope;
      scope1.should.have.property('collect', 'picture');
      scope1.should.have.property('include', 'picture');
      const employee = new Employee({id: idEmployee});
      const scope2 = employee.pictures._scope;
      scope2.should.have.property('collect', 'picture');
      scope2.should.have.property('include', 'picture');
      const picture = new Picture({id: idArticle});
      const scope3 = picture.articles._scope;
      scope3.should.have.property('collect', 'imageable');
      scope3.should.have.property('include', 'imageable');
      const scope4 = picture.employees._scope;
      scope4.should.have.property('collect', 'imageable');
      scope4.should.have.property('include', 'imageable');
    });

    let article, employee;
    const pictures = [];
    it('should create polymorphic relation - article', function(done) {
      Article.create({name: 'Article 1'}, function(err, a) {
        if (err) return done(err);
        article = a;
        article.pictures.create({name: 'Article Pic 1'}, function(err, pic) {
          if (err) return done(err);
          pictures.push(pic);
          article.pictures.create({name: 'Article Pic 2'}, function(err, pic) {
            if (err) return done(err);
            pictures.push(pic);
            done();
          });
        });
      });
    });

    it('should create polymorphic relation - employee', function(done) {
      Employee.create({name: 'Employee 1'}, function(err, r) {
        if (err) return done(err);
        employee = r;
        employee.pictures.create({name: 'Employee Pic 1'}, function(err, pic) {
          if (err) return done(err);
          pictures.push(pic);
          done();
        });
      });
    });

    it('should create polymorphic through model', function(done) {
      PictureLink.findOne(function(err, link) {
        if (err) return done(err);
        if (connectorCapabilities.adhocSort !== false) {
          link.pictureId.should.eql(pictures[0].id);
          link.imageableId.should.eql(article.id);
          link.imageableType.should.equal('Article');
          link.imageable(function(err, imageable) {
            imageable.should.be.instanceof(Article);
            imageable.id.should.eql(article.id);
            done();
          });
        } else {
          const picIds = pictures.map(pic => pic.id.toString());
          picIds.should.containEql(link.pictureId.toString());
          link.imageableType.should.be.oneOf('Article', 'Employee');
          link.imageable(function(err, imageable) {
            imageable.id.should.be.oneOf(article.id, employee.id);
            done();
          });
        }
      });
    });

    it('should get polymorphic relation through model - article', function(done) {
      if (!article) return done();
      Article.findById(article.id, function(err, article) {
        if (err) return done(err);
        article.name.should.equal('Article 1');
        article.pictures(function(err, pics) {
          if (err) return done(err);
          pics.should.have.length(2);
          const names = pics.map(p => p.name);
          const expected = ['Article Pic 1', 'Article Pic 2'];
          if (connectorCapabilities.adhocSort !== false) {
            names.should.eql(expected);
          } else {
            names.should.containDeep(expected);
          }
          done();
        });
      });
    });

    it('should get polymorphic relation through model - employee', function(done) {
      Employee.findById(employee.id, function(err, employee) {
        if (err) return done(err);
        employee.name.should.equal('Employee 1');
        employee.pictures(function(err, pics) {
          if (err) return done(err);
          pics.should.have.length(1);
          pics[0].name.should.equal('Employee Pic 1');
          done();
        });
      });
    });

    it('should include polymorphic items', function(done) {
      Article.find({include: 'pictures'}, function(err, articles) {
        articles.should.have.length(1);
        if (!articles) return done();
        articles[0].pictures(function(err, pics) {
          pics.should.have.length(2);
          const names = pics.map(p => p.name);
          const expected = ['Article Pic 1', 'Article Pic 2'];
          if (connectorCapabilities.adhocSort !== false) {
            names.should.eql(expected);
          } else {
            names.should.containDeep(expected);
          }
          done();
        });
      });
    });

    let anotherPicture;
    it('should add to a polymorphic relation - article', function(done) {
      if (!article) return done();
      Article.findById(article.id, function(err, article) {
        Picture.create({name: 'Example'}, function(err, pic) {
          if (err) return done(err);
          pictures.push(pic);
          anotherPicture = pic;
          article.pictures.add(pic, function(err, link) {
            link.should.be.instanceof(PictureLink);
            link.pictureId.should.eql(pic.id);
            link.imageableId.should.eql(article.id);
            link.imageableType.should.equal('Article');
            done();
          });
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should create polymorphic through model', function(done) {
      if (!anotherPicture) return done();
      PictureLink.findOne({where: {pictureId: anotherPicture.id, imageableType: 'Article'}},
        function(err, link) {
          if (err) return done(err);
          link.pictureId.toString().should.eql(anotherPicture.id.toString());
          link.imageableId.toString().should.eql(article.id.toString());
          link.imageableType.should.equal('Article');
          done();
        });
    });

    let anotherArticle, anotherEmployee;
    // eslint-disable-next-line mocha/no-identical-title
    it('should add to a polymorphic relation - article', function(done) {
      Article.create({name: 'Article 2'}, function(err, article) {
        if (err) return done(err);
        anotherArticle = article;
        if (!anotherPicture) return done();
        article.pictures.add(anotherPicture.id, function(err, pic) {
          if (err) return done(err);
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should add to a polymorphic relation - article', function(done) {
      Employee.create({name: 'Employee 2'}, function(err, reader) {
        if (err) return done(err);
        anotherEmployee = reader;
        if (!anotherPicture) return done();
        reader.pictures.add(anotherPicture.id, function(err, pic) {
          if (err) return done(err);
          done();
        });
      });
    });

    it('should get the inverse polymorphic relation - article', function(done) {
      if (!anotherPicture) return done();
      Picture.findById(anotherPicture.id, function(err, pic) {
        pic.articles(function(err, articles) {
          articles.should.have.length(2);
          const names = articles.map(pic => pic.name);
          const expected = ['Article 1', 'Article 2'];
          if (connectorCapabilities.adhocSort !== false) {
            names.should.eql(expected);
          } else {
            names.should.containDeep(expected);
          }
          done();
        });
      });
    });

    it('should get the inverse polymorphic relation - reader', function(done) {
      if (!anotherPicture) return done();
      Picture.findById(anotherPicture.id, function(err, pic) {
        pic.employees(function(err, employees) {
          employees.should.have.length(1);
          if (connectorCapabilities.adhocSort !== false) {
            employees[0].name.should.equal('Employee 2');
          } else {
            const employeeNames = ['Employee 1', 'Employee 2'];
            employees[0].name.should.be.oneOf(employeeNames);
          }
          done();
        });
      });
    });

    it('should find polymorphic items - article', function(done) {
      if (!article) return done();
      Article.findById(article.id, function(err, article) {
        article.pictures(function(err, pics) {
          pics.should.have.length(3);
          const names = pics.map(pic => pic.name);
          const expected = ['Article Pic 1', 'Article Pic 2', 'Example'];
          if (connectorCapabilities.adhocSort !== false) {
            names.should.eql(expected);
          } else {
            names.should.containDeep(expected);
          }
          done();
        });
      });
    });

    it('should check if polymorphic relation exists - article', function(done) {
      if (!article) return done();
      Article.findById(article.id, function(err, article) {
        article.pictures.exists(anotherPicture.id, function(err, exists) {
          exists.should.be.true;
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should remove from a polymorphic relation - article', function(done) {
        if (!article || !anotherPicture) return done();
        Article.findById(article.id, function(err, article) {
          article.pictures.remove(anotherPicture.id, function(err) {
            if (err) return done(err);
            done();
          });
        });
      });

    bdd.itIf(connectorCapabilities.cloudantCompatible !== false,
      'should find polymorphic items - article', function(done) {
        if (!article) return done();
        Article.findById(article.id, function(err, article) {
          article.pictures(function(err, pics) {
            // If deleteWithOtherThanId is not implemented, the above test is skipped and
            // the remove did not take place.  Thus +1.
            const expectedLength = connectorCapabilities.deleteWithOtherThanId !== false ?
              2 : 3;
            pics.should.have.length(expectedLength);

            const names = pics.map(p => p.name);
            if (connectorCapabilities.adhocSort !== false) {
              names.should.eql(['Article Pic 1', 'Article Pic 2']);
            } else {
              names.should.containDeep(['Article Pic 1', 'Article Pic 2', 'Example']);
            }
            done();
          });
        });
      });

    // eslint-disable-next-line mocha/no-identical-title
    it('should check if polymorphic relation exists - article', function(done) {
      if (!article) return done();
      Article.findById(article.id, function(err, article) {
        article.pictures.exists(7, function(err, exists) {
          exists.should.be.false;
          done();
        });
      });
    });

    it('should create polymorphic item through relation scope', function(done) {
      if (!anotherPicture) return done();
      Picture.findById(anotherPicture.id, function(err, pic) {
        pic.articles.create({name: 'Article 3'}, function(err, prd) {
          if (err) return done(err);
          article = prd;
          should.equal(article.name, 'Article 3');
          done();
        });
      });
    });

    it('should create polymorphic through model - new article', function(done) {
      if (!article || !anotherPicture) return done();
      PictureLink.findOne({where: {
        pictureId: anotherPicture.id, imageableId: article.id, imageableType: 'Article',
      }}, function(err, link) {
        if (err) return done(err);
        link.pictureId.toString().should.eql(anotherPicture.id.toString());
        link.imageableId.toString().should.eql(article.id.toString());
        link.imageableType.should.equal('Article');
        done();
      });
    });

    it('should find polymorphic items - new article', function(done) {
      if (!article) return done();
      Article.findById(article.id, function(err, article) {
        article.pictures(function(err, pics) {
          pics.should.have.length(1);
          pics[0].id.should.eql(anotherPicture.id);
          pics[0].name.should.equal('Example');
          done();
        });
      });
    });

    it('should use author_pictures as modelThrough', function(done) {
      Article.hasAndBelongsToMany(Picture, {throughTable: 'article_pictures'});
      Article.relations['pictures'].toJSON().should.eql({
        name: 'pictures',
        type: 'hasMany',
        modelFrom: 'Article',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'articleId',
        multiple: true,
        modelThrough: 'article_pictures',
        keyThrough: 'pictureId',
      });
      done();
    });

    it('can be declared using custom foreignKey/discriminator', function(done) {
      Article.hasAndBelongsToMany(Picture, {through: PictureLink, polymorphic: {
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }});
      Employee.hasAndBelongsToMany(Picture, {through: PictureLink, polymorphic: {
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }});
      // Optionally, define inverse relations:
      Picture.hasMany(Article, {through: PictureLink, polymorphic: {
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }, invert: true});
      Picture.hasMany(Employee, {through: PictureLink, polymorphic: {
        foreignKey: 'imageId',
        discriminator: 'imageType',
      }, invert: true});

      Article.relations['pictures'].toJSON().should.eql({
        name: 'pictures',
        type: 'hasMany',
        modelFrom: 'Article',
        keyFrom: 'id',
        modelTo: 'Picture',
        keyTo: 'imageId',
        multiple: true,
        modelThrough: 'PictureLink',
        keyThrough: 'pictureId',
        polymorphic: {
          selector: 'pictures',
          foreignKey: 'imageId',
          discriminator: 'imageType',
        },
      });

      Picture.relations['articles'].toJSON().should.eql({
        name: 'articles',
        type: 'hasMany',
        modelFrom: 'Picture',
        keyFrom: 'id',
        modelTo: 'Article',
        keyTo: 'pictureId',
        multiple: true,
        modelThrough: 'PictureLink',
        keyThrough: 'imageId',
        polymorphic: {
          foreignKey: 'imageId',
          discriminator: 'imageType',
          selector: 'articles',
          invert: true,
        },
      });

      db.automigrate(['Picture', 'Article', 'Employee', 'PictureLink'], done);
    });
  });

  describe('belongsTo', function() {
    let List, Item, Fear, Mind;

    let listId, itemId;

    it('can be declared in different ways', function() {
      List = db.define('List', {name: String});
      Item = db.define('Item', {name: String});
      Fear = db.define('Fear');
      Mind = db.define('Mind');

      // syntax 1 (old)
      Item.belongsTo(List);
      Object.keys((new Item).toObject()).should.containEql('listId');
      (new Item).list.should.be.an.instanceOf(Function);

      // syntax 2 (new)
      Fear.belongsTo('mind', {
        methods: {check: function() { return true; }},
      });

      Object.keys((new Fear).toObject()).should.containEql('mindId');
      (new Fear).mind.should.be.an.instanceOf(Function);
      // (new Fear).mind.build().should.be.an.instanceOf(Mind);
    });

    it('should setup a custom method on accessor', function() {
      const rel = Fear.relations['mind'];
      rel.defineMethod('other', function() {
        return true;
      });
    });

    it('should have setup a custom method on accessor', function() {
      const f = new Fear();
      f.mind.check.should.be.a.function;
      f.mind.check().should.be.true;
      f.mind.other.should.be.a.function;
      f.mind.other().should.be.true;
    });

    it('can be used to query data', function(done) {
      List.hasMany('todos', {model: Item});
      db.automigrate(['List', 'Item', 'Fear', 'Mind'], function() {
        List.create({name: 'List 1'}, function(e, list) {
          listId = list.id;
          should.not.exist(e);
          should.exist(list);
          list.todos.create({name: 'Item 1'}, function(err, todo) {
            itemId = todo.id;
            todo.list(function(e, l) {
              should.not.exist(e);
              should.exist(l);
              l.should.be.an.instanceOf(List);
              todo.list().id.should.eql(l.id);
              todo.list().name.should.equal('List 1');
              done();
            });
          });
        });
      });
    });

    it('can be used to query data with get() with callback', function(done) {
      List.hasMany('todos', {model: Item});
      db.automigrate(['List', 'Item', 'Fear', 'Find'], function() {
        List.create({name: 'List 1'}, function(e, list) {
          listId = list.id;
          should.not.exist(e);
          should.exist(list);
          list.todos.create({name: 'Item 1'}, function(err, todo) {
            itemId = todo.id;
            todo.list.get(function(e, l) {
              should.not.exist(e);
              should.exist(l);
              l.should.be.an.instanceOf(List);
              todo.list().id.should.eql(l.id);
              todo.list().name.should.equal('List 1');
              done();
            });
          });
        });
      });
    });

    it('can be used to query data with promises', function(done) {
      List.hasMany('todos', {model: Item});
      db.automigrate(['List', 'Item', 'Fear', 'Find'], function() {
        List.create({name: 'List 1'})
          .then(function(list) {
            listId = list.id;
            should.exist(list);
            return list.todos.create({name: 'Item 1'});
          })
          .then(function(todo) {
            itemId = todo.id;
            return todo.list.get()
              .then(function(l) {
                should.exist(l);
                l.should.be.an.instanceOf(List);
                todo.list().id.should.eql(l.id);
                todo.list().name.should.equal('List 1');
                done();
              });
          })
          .catch(done);
      });
    });

    it('could accept objects when creating on scope', function(done) {
      List.create(function(e, list) {
        should.not.exist(e);
        should.exist(list);
        Item.create({list: list}, function(err, item) {
          if (err) return done(err);
          should.exist(item);
          should.exist(item.listId);
          item.listId.should.eql(list.id);
          item.__cachedRelations.list.should.equal(list);
          done();
        });
      });
    });

    it('should update related item on scope', function(done) {
      Item.findById(itemId, function(e, todo) {
        todo.list.update({name: 'List A'}, function(err, list) {
          if (err) return done(err);
          should.exist(list);
          list.name.should.equal('List A');
          done();
        });
      });
    });

    it('should not update related item FK on scope', function(done) {
      Item.findById(itemId, function(e, todo) {
        if (e) return done(e);
        todo.list.update({id: 10}, function(err, list) {
          should.exist(err);
          err.message.should.startWith('Cannot override foreign key');
          done();
        });
      });
    });

    it('should get related item on scope', function(done) {
      Item.findById(itemId, function(e, todo) {
        todo.list(function(err, list) {
          if (err) return done(err);
          should.exist(list);
          list.name.should.equal('List A');
          done();
        });
      });
    });

    it('should destroy related item on scope', function(done) {
      Item.findById(itemId, function(e, todo) {
        todo.list.destroy(function(err) {
          if (err) return done(err);
          done();
        });
      });
    });

    it('should get related item on scope - verify', function(done) {
      Item.findById(itemId, function(e, todo) {
        todo.list(function(err, list) {
          if (err) return done(err);
          should.not.exist(list);
          done();
        });
      });
    });

    it('should not have deleted related item', function(done) {
      List.findById(listId, function(e, list) {
        should.not.exist(e);
        should.exist(list);
        done();
      });
    });

    it('should allow to create belongsTo model in beforeCreate hook', function(done) {
      let mind;
      Fear.beforeCreate = function(next) {
        this.mind.create(function(err, m) {
          mind = m;
          if (err) next(err); else next();
        });
      };
      Fear.create(function(err, fear) {
        should.not.exists(err);
        should.exists(fear);
        fear.mindId.should.eql(mind.id);
        should.exists(fear.mind());
        done();
      });
    });

    it('should allow to create belongsTo model in beforeCreate hook with promises', function(done) {
      let mind;
      Fear.beforeCreate = function(next) {
        this.mind.create()
          .then(function(m) {
            mind = m;
            next();
          }).catch(next);
      };
      Fear.create()
        .then(function(fear) {
          should.exists(fear);
          fear.mindId.should.eql(mind.id);
          should.exists(fear.mind());
          done();
        }).catch(done);
    });
  });

  describe('belongsTo with scope', function() {
    let Person, Passport;

    it('can be declared with scope and properties', function(done) {
      Person = db.define('Person', {name: String, age: Number, passportNotes: String});
      Passport = db.define('Passport', {name: String, notes: String});
      Passport.belongsTo(Person, {
        properties: {notes: 'passportNotes'},
        scope: {fields: {id: true, name: true}},
      });
      db.automigrate(['Person', 'Passport'], done);
    });

    let personCreated;
    it('should create record on scope', function(done) {
      const p = new Passport({name: 'Passport', notes: 'Some notes...'});
      p.person.create({name: 'Fred', age: 36}, function(err, person) {
        personCreated = person;
        p.personId.toString().should.eql(person.id.toString());
        person.name.should.equal('Fred');
        person.passportNotes.should.equal('Some notes...');
        p.save(function(err, passport) {
          should.not.exists(err);
          done();
        });
      });
    });

    it('should find record on scope', function(done) {
      Passport.findOne(function(err, p) {
        p.personId.toString().should.eql(personCreated.id.toString());
        p.person(function(err, person) {
          person.name.should.equal('Fred');
          person.should.have.property('age', undefined);
          person.should.have.property('passportNotes', undefined);
          done();
        });
      });
    });

    it('should create record on scope with promises', function(done) {
      const p = new Passport({name: 'Passport', notes: 'Some notes...'});
      p.person.create({name: 'Fred', age: 36})
        .then(function(person) {
          p.personId.should.eql(person.id);
          person.name.should.equal('Fred');
          person.passportNotes.should.equal('Some notes...');
          return p.save();
        })
        .then(function(passport) {
          done();
        })
        .catch(done);
    });

    it('should find record on scope with promises', function(done) {
      Passport.findOne()
        .then(function(p) {
          if (connectorCapabilities.adhocSort !== false) {
          // We skip the check if adhocSort is not supported because
          // the first row returned may or may not be the same
            p.personId.should.eql(personCreated.id);
          }
          return p.person.get();
        })
        .then(function(person) {
          person.name.should.equal('Fred');
          person.should.have.property('age', undefined);
          person.should.have.property('passportNotes', undefined);
          done();
        })
        .catch(done);
    });
  });

  // Disable the tests until the issue in
  // https://github.com/strongloop/loopback-datasource-juggler/pull/399
  // is fixed
  describe.skip('belongsTo with embed', function() {
    let Person, Passport;

    it('can be declared with embed and properties', function(done) {
      Person = db.define('Person', {name: String, age: Number});
      Passport = db.define('Passport', {name: String, notes: String});
      Passport.belongsTo(Person, {
        properties: ['name'],
        options: {embedsProperties: true, invertProperties: true},
      });
      db.automigrate(['Person', 'Passport'], done);
    });

    it('should create record with embedded data', function(done) {
      Person.create({name: 'Fred', age: 36}, function(err, person) {
        const p = new Passport({name: 'Passport', notes: 'Some notes...'});
        p.person(person);
        p.personId.should.eql(person.id);
        const data = p.toObject(true);
        data.person.id.should.eql(person.id);
        data.person.name.should.equal('Fred');
        p.save(function(err) {
          should.not.exists(err);
          done();
        });
      });
    });

    it('should find record with embedded data', function(done) {
      Passport.findOne(function(err, p) {
        should.not.exists(err);
        const data = p.toObject(true);
        data.person.id.should.eql(p.personId);
        data.person.name.should.equal('Fred');
        done();
      });
    });

    it('should find record with embedded data with promises', function(done) {
      Passport.findOne()
        .then(function(p) {
          const data = p.toObject(true);
          data.person.id.should.eql(p.personId);
          data.person.name.should.equal('Fred');
          done();
        }).catch(done);
    });
  });

  describe('hasOne', function() {
    let Supplier, Account;
    let supplierId, accountId;

    before(function() {
      Supplier = db.define('Supplier', {name: String});
      Account = db.define('Account', {accountNo: String, supplierName: String});
    });

    it('can be declared using hasOne method', function() {
      Supplier.hasOne(Account, {
        properties: {name: 'supplierName'},
        methods: {check: function() { return true; }},
      });
      Object.keys((new Account()).toObject()).should.containEql('supplierId');
      (new Supplier()).account.should.be.an.instanceOf(Function);
    });

    it('should setup a custom method on accessor', function() {
      const rel = Supplier.relations['account'];
      rel.defineMethod('other', function() {
        return true;
      });
    });

    it('should have setup a custom method on accessor', function() {
      const s = new Supplier();
      s.account.check.should.be.a.function;
      s.account.check().should.be.true;
      s.account.other.should.be.a.function;
      s.account.other().should.be.true;
    });

    it('can be used to query data', function(done) {
      db.automigrate(['Supplier', 'Account'], function() {
        Supplier.create({name: 'Supplier 1'}, function(e, supplier) {
          supplierId = supplier.id;
          should.not.exist(e);
          should.exist(supplier);
          supplier.account.create({accountNo: 'a01'}, function(err, account) {
            supplier.account(function(e, act) {
              accountId = act.id;
              should.not.exist(e);
              should.exist(act);
              act.should.be.an.instanceOf(Account);
              supplier.account().id.should.eql(act.id);
              act.supplierName.should.equal(supplier.name);
              done();
            });
          });
        });
      });
    });

    it('can be used to query data with get() with callback', function(done) {
      db.automigrate(['Supplier', 'Account'], function() {
        Supplier.create({name: 'Supplier 1'}, function(e, supplier) {
          supplierId = supplier.id;
          should.not.exist(e);
          should.exist(supplier);
          supplier.account.create({accountNo: 'a01'}, function(err, account) {
            supplier.account.get(function(e, act) {
              accountId = act.id;
              should.not.exist(e);
              should.exist(act);
              act.should.be.an.instanceOf(Account);
              supplier.account().id.should.eql(act.id);
              act.supplierName.should.equal(supplier.name);
              done();
            });
          });
        });
      });
    });

    it('can be used to query data with promises', function(done) {
      db.automigrate(['Supplier', 'Account'], function() {
        Supplier.create({name: 'Supplier 1'})
          .then(function(supplier) {
            supplierId = supplier.id;
            should.exist(supplier);
            return supplier.account.create({accountNo: 'a01'})
              .then(function(account) {
                return supplier.account.get();
              })
              .then(function(act) {
                accountId = act.id;
                should.exist(act);
                act.should.be.an.instanceOf(Account);
                supplier.account().id.should.eql(act.id);
                act.supplierName.should.equal(supplier.name);
                done();
              });
          })
          .catch(done);
      });
    });

    it('should set targetClass on scope property', function() {
      should.equal(Supplier.prototype.account._targetClass, 'Account');
    });

    it('should update the related item on scope', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        supplier.account.update({supplierName: 'Supplier A'}, function(err, act) {
          should.not.exist(e);
          act.supplierName.should.equal('Supplier A');
          done();
        });
      });
    });

    it('should not update the related item FK on scope', function(done) {
      Supplier.findById(supplierId, function(err, supplier) {
        if (err) return done(err);
        should.exist(supplier);
        supplier.account.update({supplierName: 'Supplier A', supplierId: 10}, function(err, acct) {
          should.exist(err);
          err.message.should.containEql('Cannot override foreign key');
          done();
        });
      });
    });

    it('should update the related item on scope with promises', function(done) {
      Supplier.findById(supplierId)
        .then(function(supplier) {
          should.exist(supplier);
          return supplier.account.update({supplierName: 'Supplier B'});
        })
        .then(function(act) {
          act.supplierName.should.equal('Supplier B');
          done();
        })
        .catch(done);
    });

    it('should error trying to change the foreign key in the update', function(done) {
      Supplier.create({name: 'Supplier 2'}, function(e, supplier) {
        const sid = supplier.id;
        Supplier.findById(supplierId, function(e, supplier) {
          should.not.exist(e);
          should.exist(supplier);
          supplier.account.update({supplierName: 'Supplier A',
            supplierId: sid},
          function(err, act) {
            should.exist(err);
            err.message.should.startWith('Cannot override foreign key');
            done();
          });
        });
      });
    });

    it('should update the related item on scope with same foreign key', function(done) {
      Supplier.create({name: 'Supplier 2'}, function(err, supplier) {
        Supplier.findById(supplierId, function(err, supplier) {
          if (err) return done(err);
          should.exist(supplier);
          supplier.account.update({supplierName: 'Supplier A',
            supplierId: supplierId},
          function(err, act) {
            if (err) return done(err);
            act.supplierName.should.equal('Supplier A');
            act.supplierId.toString().should.eql(supplierId.toString());
            done();
          });
        });
      });
    });

    it('should get the related item on scope', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        supplier.account(function(err, act) {
          should.not.exist(e);
          should.exist(act);
          act.supplierName.should.equal('Supplier A');
          done();
        });
      });
    });

    it('should get the related item on scope with promises', function(done) {
      Supplier.findById(supplierId)
        .then(function(supplier) {
          should.exist(supplier);
          return supplier.account.get();
        })
        .then(function(act) {
          should.exist(act);
          act.supplierName.should.equal('Supplier A');
          done();
        })
        .catch(done);
    });

    it('should destroy the related item on scope', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        supplier.account.destroy(function(err) {
          should.not.exist(e);
          done();
        });
      });
    });

    it('should destroy the related item on scope with promises', function(done) {
      Supplier.findById(supplierId)
        .then(function(supplier) {
          should.exist(supplier);
          return supplier.account.create({accountNo: 'a01'})
            .then(function(account) {
              return supplier.account.destroy();
            })
            .then(function(err) {
              done();
            });
        })
        .catch(done);
    });

    it('should get the related item on scope - verify', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        supplier.account(function(err, act) {
          should.not.exist(e);
          should.not.exist(act);
          done();
        });
      });
    });

    it('should get the related item on scope with promises - verify', function(done) {
      Supplier.findById(supplierId)
        .then(function(supplier) {
          should.exist(supplier);
          return supplier.account.get();
        })
        .then(function(act) {
          should.not.exist(act);
          done();
        })
        .catch(done);
    });

    it('should have deleted related item', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        done();
      });
    });
  });

  describe('hasOne with scope', function() {
    let Supplier, Account;
    let supplierId, accountId;

    before(function() {
      Supplier = db.define('Supplier', {name: String});
      Account = db.define('Account', {accountNo: String, supplierName: String, block: Boolean});
      Supplier.hasOne(Account, {scope: {where: {block: false}}, properties: {name: 'supplierName'}});
    });

    it('can be used to query data', function(done) {
      db.automigrate(['Supplier', 'Account'], function() {
        Supplier.create({name: 'Supplier 1'}, function(e, supplier) {
          supplierId = supplier.id;
          should.not.exist(e);
          should.exist(supplier);
          supplier.account.create({accountNo: 'a01', block: false}, function(err, account) {
            supplier.account(function(e, act) {
              accountId = act.id;
              should.not.exist(e);
              should.exist(act);
              act.should.be.an.instanceOf(Account);
              should.exist(act.block);
              act.block.should.be.false;
              supplier.account().id.should.eql(act.id);
              act.supplierName.should.equal(supplier.name);
              done();
            });
          });
        });
      });
    });

    it('should include record that matches scope', function(done) {
      Supplier.findById(supplierId, {include: 'account'}, function(err, supplier) {
        should.exists(supplier.toJSON().account);
        supplier.account(function(err, account) {
          should.exists(account);
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.supportUpdateWithoutId !== false,
      'should not find record that does not match scope', function(done) {
        Account.updateAll({block: true}, function(err) {
          if (err) return done(err);
          Supplier.findById(supplierId, function(err, supplier) {
            supplier.account(function(err, account) {
              should.not.exists(account);
              done();
            });
          });
        });
      });

    bdd.itIf(connectorCapabilities.supportUpdateWithoutId !== false,
      'should not include record that does not match scope', function(done) {
        Account.updateAll({block: true}, function(err) {
          if (err) return done(err);
          Supplier.findById(supplierId, {include: 'account'}, function(err, supplier) {
            should.not.exists(supplier.toJSON().account);
            supplier.account(function(err, account) {
              should.not.exists(account);
              done();
            });
          });
        });
      });

    it('can be used to query data with promises', function(done) {
      db.automigrate(['Supplier', 'Account'], function() {
        Supplier.create({name: 'Supplier 1'})
          .then(function(supplier) {
            supplierId = supplier.id;
            should.exist(supplier);
            return supplier.account.create({accountNo: 'a01', block: false})
              .then(function(account) {
                return supplier.account.get();
              })
              .then(function(act) {
                accountId = act.id;
                should.exist(act);
                act.should.be.an.instanceOf(Account);
                should.exist(act.block);
                act.block.should.be.false;
                supplier.account().id.should.eql(act.id);
                act.supplierName.should.equal(supplier.name);
                done();
              });
          })
          .catch(done);
      });
    });

    bdd.itIf(connectorCapabilities.supportUpdateWithoutId !== false,
      'should find record that match scope with promises', function(done) {
        Account.updateAll({block: true})
          .then(function() {
            return Supplier.findById(supplierId);
          })
          .then(function(supplier) {
            return supplier.account.get();
          })
          .then(function(account) {
            should.not.exist(account);
            done();
          })
          .catch(function(err) {
            done();
          });
      });
  });

  describe('hasOne with non standard id', function() {
    let Supplier, Account;
    let supplierId, accountId;

    before(function() {
      Supplier = db.define('Supplier', {
        sid: {
          type: String,
          id: true,
          generated: true,
        },
        name: String,
      });
      Account = db.define('Account', {
        accid: {
          type: String,
          id: true,
          generated: false,
        },
        supplierName: String,
      });
    });

    it('can be declared with non standard foreignKey', function() {
      Supplier.hasOne(Account, {
        properties: {name: 'supplierName'},
        foreignKey: 'sid',
      });
      Object.keys((new Account()).toObject()).should.containEql('sid');
      (new Supplier()).account.should.be.an.instanceOf(Function);
    });

    it('can be used to query data', function(done) {
      db.automigrate(['Supplier', 'Account'], function() {
        Supplier.create({name: 'Supplier 1'}, function(e, supplier) {
          supplierId = supplier.sid;
          should.not.exist(e);
          should.exist(supplier);
          supplier.account.create({accid: 'a01'}, function(err, account) {
            supplier.account(function(e, act) {
              accountId = act.accid;
              should.not.exist(e);
              should.exist(act);
              act.should.be.an.instanceOf(Account);
              supplier.account().accid.should.eql(act.accid);
              act.supplierName.should.equal(supplier.name);
              done();
            });
          });
        });
      });
    });

    it('should destroy the related item on scope', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        supplier.account.destroy(function(err) {
          should.not.exist(e);
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.cloudantCompatible !== false,
      'should get the related item on scope - verify', function(done) {
        Supplier.findById(supplierId, function(e, supplier) {
          should.not.exist(e);
          should.exist(supplier);
          supplier.account(function(err, act) {
            should.not.exist(e);
            should.not.exist(act);
            done();
          });
        });
      });

    it('should have deleted related item', function(done) {
      Supplier.findById(supplierId, function(e, supplier) {
        should.not.exist(e);
        should.exist(supplier);
        done();
      });
    });
  });

  describe('hasOne with primaryKey different from model PK', function() {
    let CompanyBoard, Boss;
    let companyBoardId, bossId;

    before(function() {
      CompanyBoard = db.define('CompanyBoard', {
        membersNumber: Number,
        companyId: String,
      });
      Boss = db.define('Boss', {
        id: {type: String, id: true, generated: false},
        boardMembersNumber: Number,
        companyId: String,
      });
    });

    it('relation can be declared with primaryKey', function() {
      CompanyBoard.hasOne(Boss, {
        properties: {membersNumber: 'boardMembersNumber'},
        primaryKey: 'companyId',
        foreignKey: 'companyId',
      });
      Object.keys((new Boss()).toObject()).should.containEql('companyId');
      (new CompanyBoard()).boss.should.be.an.instanceOf(Function);
    });

    it('can be used to query data', function(done) {
      db.automigrate(['CompanyBoard', 'Boss'], function() {
        CompanyBoard.create({membersNumber: 7, companyId: 'Company1'}, function(e, companyBoard) {
          companyBoardId = companyBoard.id;
          should.not.exist(e);
          should.exist(companyBoard);
          companyBoard.boss.create({id: 'bossa01'}, function(err, account) {
            companyBoard.boss(function(e, boss) {
              bossId = boss.id;
              should.not.exist(e);
              should.exist(boss);
              boss.should.be.an.instanceOf(Boss);
              companyBoard.boss().id.should.eql(boss.id);
              boss.boardMembersNumber.should.eql(companyBoard.membersNumber);
              boss.companyId.should.eql(companyBoard.companyId);
              done();
            });
          });
        });
      });
    });

    it('should destroy the related item on scope', function(done) {
      CompanyBoard.findById(companyBoardId, function(e, companyBoard) {
        should.not.exist(e);
        should.exist(companyBoard);
        companyBoard.boss.destroy(function(err) {
          should.not.exist(e);
          done();
        });
      });
    });

    it('should get the related item on scope - verify', function(done) {
      CompanyBoard.findById(companyBoardId, function(e, companyBoard) {
        should.not.exist(e);
        should.exist(companyBoard);
        companyBoard.boss(function(err, act) {
          should.not.exist(e);
          should.not.exist(act);
          done();
        });
      });
    });
  });

  describe('hasMany with primaryKey different from model PK', function() {
    let Employee, Boss;
    const COMPANY_ID = 'Company1';

    before(function() {
      Employee = db.define('Employee', {name: String, companyId: String});
      Boss = db.define('Boss', {address: String, companyId: String});
    });

    it('relation can be declared with primaryKey', function() {
      Boss.hasMany(Employee, {
        primaryKey: 'companyId',
        foreignKey: 'companyId',
      });
      (new Boss()).employees.should.be.an.instanceOf(Function);
    });

    it('can be used to query employees for boss', function() {
      return db.automigrate(['Employee', 'Boss']).then(function() {
        return Boss.create({address: 'testAddress', companyId: COMPANY_ID})
          .then(function(boss) {
            should.exist(boss);
            should.exist(boss.employees);
            return boss.employees.create([{name: 'a01'}, {name: 'a02'}])
              .then(function(employees) {
                should.exists(employees);
                return boss.employees();
              }).then(function(employees) {
                const employee = employees[0];
                should.exist(employee);
                employees.length.should.equal(2);
                employee.should.be.an.instanceOf(Employee);
                employee.companyId.should.eql(boss.companyId);
                return employees;
              });
          });
      });
    });

    it('can be used to query employees for boss2', function() {
      return db.automigrate(['Employee', 'Boss']).then(function() {
        return Boss.create({address: 'testAddress', companyId: COMPANY_ID})
          .then(function(boss) {
            return Employee.create({name: 'a01', companyId: COMPANY_ID})
              .then(function(employee) {
                should.exist(employee);
                return boss.employees.find();
              }).then(function(employees) {
                should.exists(employees);
                employees.length.should.equal(1);
              });
          });
      });
    });
  });

  describe('belongsTo with primaryKey different from model PK', function() {
    let Employee, Boss;
    const COMPANY_ID = 'Company1';
    let bossId;

    before(function() {
      Employee = db.define('Employee', {name: String, companyId: String});
      Boss = db.define('Boss', {address: String, companyId: String});
    });

    it('relation can be declared with primaryKey', function() {
      Employee.belongsTo(Boss, {
        primaryKey: 'companyId',
        foreignKey: 'companyId',
      });
      (new Employee()).boss.should.be.an.instanceOf(Function);
    });

    it('can be used to query data', function() {
      return db.automigrate(['Employee', 'Boss']).then(function() {
        return Boss.create({address: 'testAddress', companyId: COMPANY_ID})
          .then(function(boss) {
            bossId = boss.id;
            return Employee.create({name: 'a', companyId: COMPANY_ID});
          })
          .then(function(employee) {
            should.exists(employee);
            return employee.boss.get();
          })
          .then(function(boss) {
            should.exists(boss);
            boss.id.should.eql(bossId);
          });
      });
    });
  });

  describe('hasAndBelongsToMany', function() {
    let Article, TagName, ArticleTag;
    it('can be declared', function(done) {
      Article = db.define('Article', {title: String});
      TagName = db.define('TagName', {name: String, flag: String});
      Article.hasAndBelongsToMany('tagNames');
      ArticleTag = db.models.ArticleTagName;
      db.automigrate(['Article', 'TagName', 'ArticleTagName'], done);
    });

    it('should allow to create instances on scope', function(done) {
      Article.create(function(e, article) {
        article.tagNames.create({name: 'popular'}, function(e, t) {
          t.should.be.an.instanceOf(TagName);
          ArticleTag.findOne(function(e, at) {
            should.exist(at);
            at.tagNameId.toString().should.eql(t.id.toString());
            at.articleId.toString().should.eql(article.id.toString());
            done();
          });
        });
      });
    });

    it('should allow to fetch scoped instances', function(done) {
      Article.findOne(function(e, article) {
        article.tagNames(function(e, tags) {
          should.not.exist(e);
          should.exist(tags);

          article.tagNames().should.eql(tags);

          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should destroy all related instances', function(done) {
        Article.create(function(err, article) {
          if (err) return done(err);
          article.tagNames.create({name: 'popular'}, function(err, t) {
            if (err) return done(err);
            article.tagNames.destroyAll(function(err) {
              if (err) return done(err);
              article.tagNames(true, function(err, list) {
                if (err) return done(err);
                list.should.have.length(0);
                done();
              });
            });
          });
        });
      });

    it('should allow to add connection with instance', function(done) {
      Article.findOne(function(e, article) {
        TagName.create({name: 'awesome'}, function(e, tag) {
          article.tagNames.add(tag, function(e, at) {
            should.not.exist(e);
            should.exist(at);
            at.should.be.an.instanceOf(ArticleTag);
            at.tagNameId.should.eql(tag.id);
            at.articleId.should.eql(article.id);
            done();
          });
        });
      });
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should allow to remove connection with instance', function(done) {
        Article.findOne(function(e, article) {
          article.tagNames(function(e, tags) {
            const len = tags.length;
            tags.should.not.be.empty;
            article.tagNames.remove(tags[0], function(e) {
              should.not.exist(e);
              article.tagNames(true, function(e, tags) {
                tags.should.have.lengthOf(len - 1);
                done();
              });
            });
          });
        });
      });

    it('should allow to create instances on scope with promises', function(done) {
      db.automigrate(['Article', 'TagName', 'ArticleTagName'], function() {
        Article.create()
          .then(function(article) {
            return article.tagNames.create({name: 'popular'})
              .then(function(t) {
                t.should.be.an.instanceOf(TagName);
                return ArticleTag.findOne()
                  .then(function(at) {
                    should.exist(at);
                    at.tagNameId.toString().should.eql(t.id.toString());
                    at.articleId.toString().should.eql(article.id.toString());
                    done();
                  });
              });
          }).catch(done);
      });
    });

    it('should allow to fetch scoped instances with promises', function(done) {
      Article.findOne()
        .then(function(article) {
          return article.tagNames.find()
            .then(function(tags) {
              should.exist(tags);
              article.tagNames().should.eql(tags);
              done();
            });
        }).catch(done);
    });

    it('should allow to add connection with instance with promises', function(done) {
      Article.findOne()
        .then(function(article) {
          return TagName.create({name: 'awesome'})
            .then(function(tag) {
              return article.tagNames.add(tag)
                .then(function(at) {
                  should.exist(at);
                  at.should.be.an.instanceOf(ArticleTag);
                  at.tagNameId.should.eql(tag.id);
                  at.articleId.should.eql(article.id);
                  done();
                });
            });
        })
        .catch(done);
    });

    bdd.itIf(connectorCapabilities.deleteWithOtherThanId !== false,
      'should allow to remove connection with instance with promises', function(done) {
        Article.findOne()
          .then(function(article) {
            return article.tagNames.find()
              .then(function(tags) {
                const len = tags.length;
                tags.should.not.be.empty;
                return article.tagNames.remove(tags[0])
                  .then(function() {
                    return article.tagNames.find();
                  })
                  .then(function(tags) {
                    tags.should.have.lengthOf(len - 1);
                    done();
                  });
              });
          })
          .catch(done);
      });

    it('should set targetClass on scope property', function() {
      should.equal(Article.prototype.tagNames._targetClass, 'TagName');
    });

    it('should apply inclusion fields to the target model', function(done) {
      Article.create({title: 'a1'}, function(e, article) {
        should.not.exist(e);
        article.tagNames.create({name: 't1', flag: '1'}, function(e, t) {
          should.not.exist(e);
          Article.find({
            where: {id: article.id},
            include: {relation: 'tagNames', scope: {fields: ['name']}}},
          function(e, articles) {
            should.not.exist(e);
            articles.should.have.property('length', 1);
            const a = articles[0].toJSON();
            a.should.have.property('title', 'a1');
            a.should.have.property('tagNames');
            a.tagNames.should.have.property('length', 1);
            const n = a.tagNames[0];
            n.should.have.property('name', 't1');
            n.should.have.property('flag', undefined);
            n.id.should.eql(t.id);
            done();
          });
        });
      });
    });

    it('should apply inclusion where to the target model', function(done) {
      Article.create({title: 'a2'}, function(e, article) {
        should.not.exist(e);
        article.tagNames.create({name: 't2', flag: '2'}, function(e, t2) {
          should.not.exist(e);
          article.tagNames.create({name: 't3', flag: '3'}, function(e, t3) {
            Article.find({
              where: {id: article.id},
              include: {relation: 'tagNames', scope: {where: {flag: '2'}}}},
            function(e, articles) {
              should.not.exist(e);
              articles.should.have.property('length', 1);
              const a = articles[0].toJSON();
              a.should.have.property('title', 'a2');
              a.should.have.property('tagNames');
              a.tagNames.should.have.property('length', 1);
              const n = a.tagNames[0];
              n.should.have.property('name', 't2');
              n.should.have.property('flag', '2');
              n.id.should.eql(t2.id);
              done();
            });
          });
        });
      });
    });
  });

  describe('embedsOne', function() {
    let person;
    let Passport;
    let Other;

    before(function() {
      tmp = getTransientDataSource();
      Person = db.define('Person', {name: String});
      Passport = tmp.define('Passport',
        {name: {type: 'string', required: true}},
        {idInjection: false});
      Address = tmp.define('Address', {street: String}, {idInjection: false});
      Other = db.define('Other', {name: String});
      Person.embedsOne(Passport, {
        default: {name: 'Anonymous'}, // a bit contrived
        methods: {check: function() { return true; }},
        options: {
          property: {
            postgresql: {
              columnName: 'passport_item',
            },
          },
        },
      });
    });

    it('can be declared using embedsOne method', function(done) {
      Person.embedsOne(Address); // all by default
      db.automigrate(['Person'], done);
    });

    it('should have setup a property and accessor', function() {
      const p = new Person();
      p.passport.should.be.an.object; // because of default
      p.passportItem.should.be.a.function;
      p.passportItem.create.should.be.a.function;
      p.passportItem.build.should.be.a.function;
      p.passportItem.destroy.should.be.a.function;
    });

    it('respects property options on the embedded property', function() {
      Person.definition.properties.passport.should.have.property('postgresql');
      Person.definition.properties.passport.postgresql.should.eql({columnName: 'passport_item'});
    });

    it('should setup a custom method on accessor', function() {
      const rel = Person.relations['passportItem'];
      rel.defineMethod('other', function() {
        return true;
      });
    });

    it('should have setup a custom method on accessor', function() {
      const p = new Person();
      p.passportItem.check.should.be.a.function;
      p.passportItem.check().should.be.true;
      p.passportItem.other.should.be.a.function;
      p.passportItem.other().should.be.true;
    });

    it('should behave properly without default or being set', function(done) {
      const p = new Person();
      should.not.exist(p.address);
      const a = p.addressItem();
      should.not.exist(a);
      Person.create({}, function(err, p) {
        should.not.exist(p.address);
        const a = p.addressItem();
        should.not.exist(a);
        done();
      });
    });

    it('should return an instance with default values', function() {
      const p = new Person();
      p.passport.toObject().should.eql({name: 'Anonymous'});
      p.passportItem().should.equal(p.passport);
      p.passportItem(function(err, passport) {
        should.not.exist(err);
        passport.should.equal(p.passport);
      });
    });

    it('should embed a model instance', function() {
      const p = new Person();
      p.passportItem(new Passport({name: 'Fred'}));
      p.passport.toObject().should.eql({name: 'Fred'});
      p.passport.should.be.an.instanceOf(Passport);
    });

    it('should not embed an invalid model type', function() {
      const p = new Person();
      p.passportItem(new Other());
      p.passport.toObject().should.eql({name: 'Anonymous'});
      p.passport.should.be.an.instanceOf(Passport);
    });

    let personId;
    it('should create an embedded item on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        if (err) return done(err);
        personId = p.id;
        p.passportItem.create({name: 'Fredric'}, function(err, passport) {
          if (err) return done(err);
          p.passport.toObject().should.eql({name: 'Fredric'});
          p.passport.should.be.an.instanceOf(Passport);
          done();
        });
      });
    });

    it('should get an embedded item on scope', function(done) {
      Person.findById(personId, function(err, p) {
        if (err) return done(err);
        const passport = p.passportItem();
        passport.toObject().should.eql({name: 'Fredric'});
        passport.should.be.an.instanceOf(Passport);
        passport.should.equal(p.passport);
        passport.should.equal(p.passportItem.value());
        done();
      });
    });

    it('should validate an embedded item on scope - on creation', function(done) {
      const p = new Person({name: 'Fred'});
      p.passportItem.create({}, function(err, passport) {
        should.exist(err);
        err.name.should.equal('ValidationError');
        err.details.messages.name.should.eql(['can\'t be blank']);
        done();
      });
    });

    it('should validate an embedded item on scope - on update', function(done) {
      Person.findById(personId, function(err, p) {
        const passport = p.passportItem();
        passport.name = null;
        p.save(function(err) {
          should.exist(err);
          err.name.should.equal('ValidationError');
          err.details.messages.passportItem
            .should.eql(['is invalid: `name` can\'t be blank']);
          done();
        });
      });
    });

    it('should update an embedded item on scope', function(done) {
      Person.findById(personId, function(err, p) {
        p.passportItem.update({name: 'Freddy'}, function(err, passport) {
          if (err) return done(err);
          passport = p.passportItem();
          passport.toObject().should.eql({name: 'Freddy'});
          passport.should.be.an.instanceOf(Passport);
          passport.should.equal(p.passport);
          done();
        });
      });
    });

    it('should get an embedded item on scope - verify', function(done) {
      Person.findById(personId, function(err, p) {
        if (err) return done(err);
        const passport = p.passportItem();
        passport.toObject().should.eql({name: 'Freddy'});
        done();
      });
    });

    it('should destroy an embedded item on scope', function(done) {
      Person.findById(personId, function(err, p) {
        p.passportItem.destroy(function(err) {
          if (err) return done(err);
          should.equal(p.passport, null);
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should get an embedded item on scope - verify', function(done) {
      Person.findById(personId, function(err, p) {
        if (err) return done(err);
        should.equal(p.passport, null);
        done();
      });
    });

    it('should save an unsaved model', function(done) {
      const p = new Person({name: 'Fred'});
      p.isNewRecord().should.be.true;
      p.passportItem.create({name: 'Fredric'}, function(err, passport) {
        if (err) return done(err);
        p.passport.should.equal(passport);
        p.isNewRecord().should.be.false;
        done();
      });
    });

    it('should create an embedded item on scope with promises', function(done) {
      Person.create({name: 'Fred'})
        .then(function(p) {
          personId = p.id;
          p.passportItem.create({name: 'Fredric'})
            .then(function(passport) {
              p.passport.toObject().should.eql({name: 'Fredric'});
              p.passport.should.be.an.instanceOf(Passport);
              done();
            });
        }).catch(done);
    });

    it('should get an embedded item on scope with promises', function(done) {
      Person.findById(personId)
        .then(function(p) {
          const passport = p.passportItem();
          passport.toObject().should.eql({name: 'Fredric'});
          passport.should.be.an.instanceOf(Passport);
          passport.should.equal(p.passport);
          passport.should.equal(p.passportItem.value());
          done();
        }).catch(done);
    });

    it('should validate an embedded item on scope with promises - on creation', function(done) {
      const p = new Person({name: 'Fred'});
      p.passportItem.create({})
        .then(function(passport) {
          should.not.exist(passport);
          done();
        })
        .catch(function(err) {
          should.exist(err);
          err.name.should.equal('ValidationError');
          err.details.messages.name.should.eql(['can\'t be blank']);
          done();
        }).catch(done);
    });

    it('should validate an embedded item on scope with promises - on update', function(done) {
      Person.findById(personId)
        .then(function(p) {
          const passport = p.passportItem();
          passport.name = null;
          return p.save()
            .then(function(p) {
              should.not.exist(p);
              done();
            })
            .catch(function(err) {
              should.exist(err);
              err.name.should.equal('ValidationError');
              err.details.messages.passportItem
                .should.eql(['is invalid: `name` can\'t be blank']);
              done();
            });
        }).catch(done);
    });

    it('should update an embedded item on scope with promises', function(done) {
      Person.findById(personId)
        .then(function(p) {
          return p.passportItem.update({name: 'Jason'})
            .then(function(passport) {
              passport = p.passportItem();
              passport.toObject().should.eql({name: 'Jason'});
              passport.should.be.an.instanceOf(Passport);
              passport.should.equal(p.passport);
              done();
            });
        }).catch(done);
    });

    it('should get an embedded item on scope with promises - verify', function(done) {
      Person.findById(personId)
        .then(function(p) {
          const passport = p.passportItem();
          passport.toObject().should.eql({name: 'Jason'});
          done();
        }).catch(done);
    });

    it('should destroy an embedded item on scope with promises', function(done) {
      Person.findById(personId)
        .then(function(p) {
          return p.passportItem.destroy()
            .then(function() {
              should.equal(p.passport, null);
              done();
            });
        }).catch(done);
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should get an embedded item on scope with promises - verify', function(done) {
      Person.findById(personId)
        .then(function(p) {
          should.equal(p.passport, null);
          done();
        }).catch(done);
    });

    it('should also save changes when directly saving the embedded model', function(done) {
      // Passport should normally have an id for the direct save to work. For now override the check
      const originalHasPK = Passport.definition.hasPK;
      Passport.definition.hasPK = function() { return true; };
      Person.findById(personId)
        .then(function(p) {
          return p.passportItem.create({name: 'Mitsos'});
        })
        .then(function(passport) {
          passport.name = 'Jim';
          return passport.save();
        })
        .then(function() {
          return Person.findById(personId);
        })
        .then(function(person) {
          person.passportItem().toObject().should.eql({name: 'Jim'});
          // restore original hasPk
          Passport.definition.hasPK = originalHasPK;
          done();
        })
        .catch(function(err) {
          Passport.definition.hasPK = originalHasPK;
          done(err);
        });
    });

    it('should delete the embedded document and also update parent', function(done) {
      const originalHasPK = Passport.definition.hasPK;
      Passport.definition.hasPK = function() { return true; };
      Person.findById(personId)
        .then(function(p) {
          return p.passportItem().destroy();
        })
        .then(function() {
          return Person.findById(personId);
        })
        .then(function(person) {
          person.should.have.property('passport', null);
          done();
        })
        .catch(function(err) {
          Passport.definition.hasPK = originalHasPK;
          done(err);
        });
    });
  });

  describe('embedsOne - persisted model', function() {
    // This test spefically uses the Memory connector
    // in order to test the use of the auto-generated
    // id, in the sequence of the related model.
    let Passport, Person;
    before(function() {
      db = getMemoryDataSource();
      Person = db.define('Person', {name: String});
      Passport = db.define('Passport',
        {name: {type: 'string', required: true}});
    });

    it('can be declared using embedsOne method', function(done) {
      Person.embedsOne(Passport, {
        options: {persistent: true},
      });
      db.automigrate(['Person', 'Passport'], done);
    });

    it('should create an item - to offset id', function(done) {
      Passport.create({name: 'Wilma'}, function(err, p) {
        if (err) return done(err);
        p.id.should.equal(1);
        p.name.should.equal('Wilma');
        done();
      });
    });

    it('should create an embedded item on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        if (err) return done(err);
        p.passportItem.create({name: 'Fredric'}, function(err, passport) {
          if (err) return done(err);
          p.passport.id.should.eql(2);
          p.passport.name.should.equal('Fredric');
          done();
        });
      });
    });

    it('should create an embedded item on scope with promises', function(done) {
      Person.create({name: 'Barney'})
        .then(function(p) {
          return p.passportItem.create({name: 'Barnabus'})
            .then(function(passport) {
              p.passport.id.should.eql(3);
              p.passport.name.should.equal('Barnabus');
              done();
            });
        }).catch(done);
    });
  });

  describe('embedsOne - generated id', function() {
    let Passport;
    before(function() {
      tmp = getTransientDataSource();
      Person = db.define('Person', {name: String});
      Passport = tmp.define('Passport',
        {
          id: {type: 'string', id: true, generated: true},
          name: {type: 'string', required: true},
        });
    });

    it('can be declared using embedsOne method', function(done) {
      Person.embedsOne(Passport);
      db.automigrate(['Person'], done);
    });

    it('should create an embedded item on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        if (err) return done(err);
        p.passportItem.create({name: 'Fredric'}, function(err, passport) {
          if (err) return done(err);
          passport.id.should.match(/^[0-9a-fA-F]{24}$/);
          p.passport.name.should.equal('Fredric');
          done();
        });
      });
    });
  });

  describe('embedsMany', function() {
    let address1, address2;

    before(function(done) {
      tmp = getTransientDataSource({defaultIdType: Number});
      Person = db.define('Person', {name: String});
      Address = tmp.define('Address', {street: String});
      Address.validatesPresenceOf('street');

      db.automigrate(['Person'], done);
    });

    it('can be declared', function(done) {
      Person.embedsMany(Address, {
        options: {
          property: {
            postgresql: {
              dataType: 'json',
            },
          },
        },
      });
      db.automigrate(['Person'], done);
    });

    it('should have setup embedded accessor/scope', function() {
      const p = new Person({name: 'Fred'});
      p.addresses.should.be.an.array;
      p.addresses.should.have.length(0);
      p.addressList.should.be.a.function;
      p.addressList.findById.should.be.a.function;
      p.addressList.updateById.should.be.a.function;
      p.addressList.destroy.should.be.a.function;
      p.addressList.exists.should.be.a.function;
      p.addressList.create.should.be.a.function;
      p.addressList.build.should.be.a.function;
    });

    it('should create embedded items on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        p.addressList.create({street: 'Street 1'}, function(err, address) {
          if (err) return done(err);
          address1 = address;
          should.exist(address1.id);
          address1.street.should.equal('Street 1');
          done();
        });
      });
    });

    it('respects property options on the embedded property', function() {
      Person.definition.properties.addresses.should.have.property('postgresql');
      Person.definition.properties.addresses.postgresql.should.eql({dataType: 'json'});
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should create embedded items on scope', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.create({street: 'Street 2'}, function(err, address) {
          if (err) return done(err);
          address2 = address;
          should.exist(address2.id);
          address2.street.should.equal('Street 2');
          done();
        });
      });
    });

    it('should return embedded items from scope', function(done) {
      Person.findOne(function(err, p) {
        p.addressList(function(err, addresses) {
          if (err) return done(err);

          const list = p.addressList();
          list.should.equal(addresses);
          list.should.equal(p.addresses);

          p.addressList.value().should.equal(list);

          addresses.should.have.length(2);
          addresses[0].id.should.eql(address1.id);
          addresses[0].street.should.equal('Street 1');
          addresses[1].id.should.eql(address2.id);
          addresses[1].street.should.equal('Street 2');
          done();
        });
      });
    });

    it('should filter embedded items on scope', function(done) {
      Person.findOne(function(err, p) {
        p.addressList({where: {street: 'Street 2'}}, function(err, addresses) {
          if (err) return done(err);
          addresses.should.have.length(1);
          addresses[0].id.should.eql(address2.id);
          addresses[0].street.should.equal('Street 2');
          done();
        });
      });
    });

    it('should validate embedded items', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.create({}, function(err, address) {
          should.exist(err);
          should.not.exist(address);
          err.name.should.equal('ValidationError');
          err.details.codes.street.should.eql(['presence']);
          done();
        });
      });
    });

    it('should find embedded items by id', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.findById(address2.id, function(err, address) {
          address.should.be.instanceof(Address);
          address.id.should.eql(address2.id);
          address.street.should.equal('Street 2');
          done();
        });
      });
    });

    it('should check if item exists', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.exists(address2.id, function(err, exists) {
          if (err) return done(err);
          exists.should.be.true;
          done();
        });
      });
    });

    it('should update embedded items by id', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.updateById(address2.id, {street: 'New Street'}, function(err, address) {
          address.should.be.instanceof(Address);
          address.id.should.eql(address2.id);
          address.street.should.equal('New Street');
          done();
        });
      });
    });

    it('should validate the update of embedded items', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.updateById(address2.id, {street: null}, function(err, address) {
          err.name.should.equal('ValidationError');
          err.details.codes.street.should.eql(['presence']);
          done();
        });
      });
    });

    it('should find embedded items by id - verify', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.findById(address2.id, function(err, address) {
          address.should.be.instanceof(Address);
          address.id.should.eql(address2.id);
          address.street.should.equal('New Street');
          done();
        });
      });
    });

    it('should have accessors: at, get, set', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.at(0).id.should.eql(address1.id);
        p.addressList.get(address1.id).id.should.eql(address1.id);
        p.addressList.set(address1.id, {street: 'Changed 1'});
        p.addresses[0].street.should.equal('Changed 1');
        p.addressList.at(1).id.should.eql(address2.id);
        p.addressList.get(address2.id).id.should.eql(address2.id);
        p.addressList.set(address2.id, {street: 'Changed 2'});
        p.addresses[1].street.should.equal('Changed 2');
        done();
      });
    });

    it('should remove embedded items by id', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(2);
        p.addressList.destroy(address1.id, function(err) {
          if (err) return done(err);
          p.addresses.should.have.length(1);
          done();
        });
      });
    });

    it('should have removed embedded items - verify', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(1);
        done();
      });
    });

    it('should pass options when removed by id', function(done) {
      const verifyOptions = function(ctx, next) {
        if (!ctx.options || !ctx.options.verify) {
          return next(new Error('options or options.verify is missing'));
        }
        return next();
      };
      Person.observe('before save', verifyOptions);
      Person.findOne(function(err, p) {
        p.addressList.create({street: 'options 1'}, {verify: true}, function(err, address) {
          if (err) {
            Person.clearObservers('before save');
            return done(err);
          }
          p.addressList.destroy(address.id, {verify: true}, function(err) {
            if (err) {
              Person.clearObservers('before save');
              return done(err);
            }
            Person.findById(p.id, function(err, verify) {
              if (err) {
                Person.clearObservers('before save');
                return done(err);
              }
              verify.addresses.should.have.length(1);
              Person.clearObservers('before save');
              done();
            });
          });
        });
      });
    });

    it('should pass options when removed by where', function(done) {
      const verifyOptions = function(ctx, next) {
        if (!ctx.options || !ctx.options.verify) {
          return next(new Error('options or options.verify is missing'));
        }
        return next();
      };
      Person.observe('before save', verifyOptions);
      Person.findOne(function(err, p) {
        p.addressList.create({street: 'options 2'}, {verify: true}, function(err, address) {
          if (err) {
            Person.clearObservers('before save');
            return done(err);
          }
          p.addressList.destroyAll({street: 'options 2'}, {verify: true}, function(err) {
            if (err) {
              Person.clearObservers('before save');
              return done(err);
            }
            Person.findById(p.id, function(err, verify) {
              if (err) {
                Person.clearObservers('before save');
                return done(err);
              }
              verify.addresses.should.have.length(1);
              Person.clearObservers('before save');
              done();
            });
          });
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should create embedded items on scope', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.create({street: 'Street 3'}, function(err, address) {
          if (err) return done(err);
          address.street.should.equal('Street 3');
          done();
        });
      });
    });

    it('should remove embedded items - filtered', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(2);
        p.addressList.destroyAll({street: 'Street 3'}, function(err) {
          if (err) return done(err);
          p.addresses.should.have.length(1);
          done();
        });
      });
    });

    it('should remove all embedded items', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(1);
        p.addressList.destroyAll(function(err) {
          if (err) return done(err);
          p.addresses.should.have.length(0);
          done();
        });
      });
    });

    it('should have removed all embedded items - verify', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(0);
        done();
      });
    });

    it('should save an unsaved model', function(done) {
      const p = new Person({name: 'Fred'});
      p.isNewRecord().should.be.true;
      p.addressList.create({street: 'Street 4'}, function(err, address) {
        if (err) return done(err);
        address.street.should.equal('Street 4');
        p.isNewRecord().should.be.false;
        done();
      });
    });
  });

  describe('embedsMany - omit default value for embedded item', function() {
    before(function(done) {
      tmp = getTransientDataSource({defaultIdType: Number});
      Person = db.define('Person', {name: String});
      Address = tmp.define('Address', {street: String});
      Address.validatesPresenceOf('street');

      db.automigrate(['Person'], done);
    });

    it('can be declared', function(done) {
      Person.embedsMany(Address, {
        options: {
          omitDefaultEmbeddedItem: true,
          property: {
            postgresql: {
              dataType: 'json',
            },
          },
        },
      });
      db.automigrate(['Person'], done);
    });

    it('should not set default value for embedded item', function() {
      const p = new Person({name: 'Fred'});
      p.should.have.property('addresses', undefined);
    });

    it('should create embedded items on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        p.addressList.create({street: 'Street 1'}, function(err, address) {
          if (err) return done(err);
          should.exist(address.id);
          address.street.should.equal('Street 1');
          p.addresses.should.be.array;
          p.addresses.should.have.length(1);
          done();
        });
      });
    });

    it('should build embedded items', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(1);
        p.addressList.build({id: 'home', street: 'Home'});
        p.addressList.build({id: 'work', street: 'Work'});
        p.addresses.should.have.length(3);
        done();
      });
    });

    it('should not create embedded from attributes - relation name', function(done) {
      const addresses = [
        {id: 'home', street: 'Home Street'},
        {id: 'work', street: 'Work Street'},
      ];
      Person.create({name: 'Wilma', addressList: addresses}, function(err, p) {
        if (err) return done(err);
        p.should.have.property('addresses', undefined);
        done();
      });
    });
  });

  describe('embedsMany - numeric ids + forceId', function() {
    before(function(done) {
      tmp = getTransientDataSource();
      Person = db.define('Person', {name: String});
      Address = tmp.define('Address', {
        id: {type: Number, id: true},
        street: String,
      });

      db.automigrate(['Person'], done);
    });

    it('can be declared', function(done) {
      Person.embedsMany(Address, {options: {forceId: true}});
      db.automigrate(['Person'], done);
    });

    it('should create embedded items on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        p.addressList.create({street: 'Street 1'}, function(err, address) {
          if (err) return done(err);
          address.id.should.equal(1);
          p.addressList.create({street: 'Street 2'}, function(err, address) {
            address.id.should.equal(2);
            p.addressList.create({id: 12345, street: 'Street 3'}, function(err, address) {
              address.id.should.equal(3);
              done();
            });
          });
        });
      });
    });
  });

  describe('embedsMany - explicit ids', function() {
    before(function(done) {
      tmp = getTransientDataSource();
      Person = db.define('Person', {name: String});
      Address = tmp.define('Address', {street: String}, {forceId: false});
      Address.validatesPresenceOf('street');

      db.automigrate(['Person'], done);
    });

    it('can be declared', function(done) {
      Person.embedsMany(Address);
      db.automigrate(['Person'], done);
    });

    it('should create embedded items on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        p.addressList.create({id: 'home', street: 'Street 1'}, function(err, address) {
          if (err) return done(err);
          p.addressList.create({id: 'work', street: 'Work Street 2'}, function(err, address) {
            if (err) return done(err);
            address.id.should.equal('work');
            address.street.should.equal('Work Street 2');
            done();
          });
        });
      });
    });

    it('should find embedded items by id', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.findById('work', function(err, address) {
          address.should.be.instanceof(Address);
          address.id.should.equal('work');
          address.street.should.equal('Work Street 2');
          done();
        });
      });
    });

    it('should check for duplicate ids', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.create({id: 'home', street: 'Invalid'}, function(err, addresses) {
          should.exist(err);
          err.name.should.equal('ValidationError');
          err.details.codes.addresses.should.eql(['uniqueness']);
          done();
        });
      });
    });

    it('should update embedded items by id', function(done) {
      Person.findOne(function(err, p) {
        p.addressList.updateById('home', {street: 'New Street'}, function(err, address) {
          address.should.be.instanceof(Address);
          address.id.should.equal('home');
          address.street.should.equal('New Street');
          done();
        });
      });
    });

    it('should remove embedded items by id', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(2);
        p.addressList.destroy('home', function(err) {
          if (err) return done(err);
          p.addresses.should.have.length(1);
          done();
        });
      });
    });

    it('should have embedded items - verify', function(done) {
      Person.findOne(function(err, p) {
        p.addresses.should.have.length(1);
        done();
      });
    });

    it('should validate all embedded items', function(done) {
      const addresses = [];
      addresses.push({id: 'home', street: 'Home Street'});
      addresses.push({id: 'work', street: ''});
      Person.create({name: 'Wilma', addresses: addresses}, function(err, p) {
        err.name.should.equal('ValidationError');
        err.details.messages.addresses.should.eql([
          'contains invalid item: `work` (`street` can\'t be blank)',
        ]);
        done();
      });
    });

    it('should build embedded items', function(done) {
      Person.create({name: 'Wilma'}, function(err, p) {
        p.addressList.build({id: 'home', street: 'Home'});
        p.addressList.build({id: 'work', street: 'Work'});
        p.addresses.should.have.length(2);
        p.save(function(err, p) {
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should have embedded items - verify', function(done) {
      Person.findOne({where: {name: 'Wilma'}}, function(err, p) {
        p.name.should.equal('Wilma');
        p.addresses.should.have.length(2);
        p.addresses[0].id.should.equal('home');
        p.addresses[0].street.should.equal('Home');
        p.addresses[1].id.should.equal('work');
        p.addresses[1].street.should.equal('Work');
        done();
      });
    });

    it('should have accessors: at, get, set', function(done) {
      Person.findOne({where: {name: 'Wilma'}}, function(err, p) {
        p.name.should.equal('Wilma');
        p.addresses.should.have.length(2);
        p.addressList.at(0).id.should.equal('home');
        p.addressList.get('home').id.should.equal('home');
        p.addressList.set('home', {id: 'den'}).id.should.equal('den');
        p.addressList.at(1).id.should.equal('work');
        p.addressList.get('work').id.should.equal('work');
        p.addressList.set('work', {id: 'factory'}).id.should.equal('factory');
        done();
      });
    });

    it('should create embedded from attributes - property name', function(done) {
      const addresses = [
        {id: 'home', street: 'Home Street'},
        {id: 'work', street: 'Work Street'},
      ];
      Person.create({name: 'Wilma', addresses: addresses}, function(err, p) {
        if (err) return done(err);
        p.addressList.at(0).id.should.equal('home');
        p.addressList.at(1).id.should.equal('work');
        done();
      });
    });

    it('should not create embedded from attributes - relation name', function(done) {
      const addresses = [
        {id: 'home', street: 'Home Street'},
        {id: 'work', street: 'Work Street'},
      ];
      Person.create({name: 'Wilma', addressList: addresses}, function(err, p) {
        if (err) return done(err);
        p.addresses.should.have.length(0);
        done();
      });
    });

    it('should create embedded items with auto-generated id', function(done) {
      Person.create({name: 'Wilma'}, function(err, p) {
        p.addressList.create({street: 'Home Street 1'}, function(err, address) {
          if (err) return done(err);
          address.id.should.match(/^[0-9a-fA-F]{24}$/);
          address.street.should.equal('Home Street 1');
          done();
        });
      });
    });
  });

  describe('embedsMany - persisted model', function() {
    let address0, address1, address2;
    let person;

    // This test spefically uses the Memory connector
    // in order to test the use of the auto-generated
    // id, in the sequence of the related model.

    before(function(done) {
      db = getMemoryDataSource();
      Person = db.define('Person', {name: String});
      Address = db.define('Address', {street: String});
      Address.validatesPresenceOf('street');

      db.automigrate(['Person', 'Address'], done);
    });

    it('can be declared', function(done) {
      // to save related model itself, set
      // persistent: true
      Person.embedsMany(Address, {
        scope: {order: 'street'},
        options: {persistent: true},
      });
      db.automigrate(['Person', 'Address'], done);
    });

    it('should create individual items (0)', function(done) {
      Address.create({street: 'Street 0'}, function(err, inst) {
        inst.id.should.equal(1); // offset sequence
        address0 = inst;
        done();
      });
    });

    it('should create individual items (1)', function(done) {
      Address.create({street: 'Street 1'}, function(err, inst) {
        inst.id.should.equal(2);
        address1 = inst;
        done();
      });
    });

    it('should create individual items (2)', function(done) {
      Address.create({street: 'Street 2'}, function(err, inst) {
        inst.id.should.equal(3);
        address2 = inst;
        done();
      });
    });

    it('should create individual items (3)', function(done) {
      Address.create({street: 'Street 3'}, function(err, inst) {
        inst.id.should.equal(4); // offset sequence
        done();
      });
    });

    it('should add embedded items on scope', function(done) {
      Person.create({name: 'Fred'}, function(err, p) {
        person = p;
        p.addressList.create(address1.toObject(), function(err, address) {
          if (err) return done(err);
          address.id.should.eql(2);
          address.street.should.equal('Street 1');
          p.addressList.create(address2.toObject(), function(err, address) {
            if (err) return done(err);
            address.id.should.eql(3);
            address.street.should.equal('Street 2');
            done();
          });
        });
      });
    });

    it('should create embedded items on scope', function(done) {
      Person.findById(person.id, function(err, p) {
        p.addressList.create({street: 'Street 4'}, function(err, address) {
          if (err) return done(err);
          address.id.should.equal(5); // in Address sequence, correct offset
          address.street.should.equal('Street 4');
          done();
        });
      });
    });

    it('should have embedded items on scope', function(done) {
      Person.findById(person.id, function(err, p) {
        p.addressList(function(err, addresses) {
          if (err) return done(err);
          addresses.should.have.length(3);
          addresses[0].street.should.equal('Street 1');
          addresses[1].street.should.equal('Street 2');
          addresses[2].street.should.equal('Street 4');
          done();
        });
      });
    });

    it('should validate embedded items on scope - id', function(done) {
      Person.create({name: 'Wilma'}, function(err, p) {
        p.addressList.create({id: null, street: 'Street 1'}, function(err, address) {
          if (err) return done(err);
          address.street.should.equal('Street 1');
          done();
        });
      });
    });

    it('should validate embedded items on scope - street', function(done) {
      const newId = uid.fromConnector(db) || 1234;
      Person.create({name: 'Wilma'}, function(err, p) {
        p.addressList.create({id: newId}, function(err, address) {
          should.exist(err);
          err.name.should.equal('ValidationError');
          err.details.codes.street.should.eql(['presence']);
          let expected = 'The `Address` instance is not valid. ';
          expected += 'Details: `street` can\'t be blank (value: undefined).';
          err.message.should.equal(expected);
          done();
        });
      });
    });
  });

  describe('embedsMany - relations, scope and properties', function() {
    let category, job1, job2, job3;

    before(function() {
      Category = db.define('Category', {name: String});
      Job = db.define('Job', {name: String});
      Link = db.define('Link', {name: String, notes: String}, {forceId: false});
    });

    it('can be declared', function(done) {
      Category.embedsMany(Link, {
        as: 'items', // rename
        scope: {include: 'job'}, // always include
        options: {belongsTo: 'job'}, // optional, for add()/remove()
      });
      Link.belongsTo(Job, {
        foreignKey: 'id', // re-use the actual job id
        properties: {id: 'id', name: 'name'}, // denormalize, transfer id
        options: {invertProperties: true},
      });
      db.automigrate(['Category', 'Job', 'Link'], function() {
        Job.create({name: 'Job 0'}, done); // offset ids for tests
      });
    });

    it('should setup related items', function(done) {
      Job.create({name: 'Job 1'}, function(err, p) {
        if (err) return done(err);
        job1 = p;
        Job.create({name: 'Job 2'}, function(err, p) {
          if (err) return done(err);
          job2 = p;
          Job.create({name: 'Job 3'}, function(err, p) {
            if (err) return done(err);
            job3 = p;
            done();
          });
        });
      });
    });

    it('should associate items on scope', function(done) {
      Category.create({name: 'Category A'}, function(err, cat) {
        if (err) return done(err);
        let link = cat.items.build();
        link.job(job1);
        link = cat.items.build();
        link.job(job2);
        cat.save(function(err, cat) {
          if (err) return done(err);
          let job = cat.items.at(0);
          job.should.be.instanceof(Link);
          job.should.not.have.property('jobId');
          job.id.should.eql(job1.id);
          job.name.should.equal(job1.name);
          job = cat.items.at(1);
          job.id.should.eql(job2.id);
          job.name.should.equal(job2.name);
          done();
        });
      });
    });

    it('should include related items on scope', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(2);

        // denormalized properties:
        cat.items.at(0).should.be.instanceof(Link);
        cat.items.at(0).id.should.eql(job1.id);
        cat.items.at(0).name.should.equal(job1.name);
        cat.items.at(1).id.should.eql(job2.id);
        cat.items.at(1).name.should.equal(job2.name);

        // lazy-loaded relations
        should.not.exist(cat.items.at(0).job());
        should.not.exist(cat.items.at(1).job());

        cat.items(function(err, items) {
          if (err) return done(err);
          cat.items.at(0).job().should.be.instanceof(Job);
          cat.items.at(1).job().should.be.instanceof(Job);
          cat.items.at(1).job().name.should.equal('Job 2');
          done();
        });
      });
    });

    it('should remove embedded items by id', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(2);
        cat.items.destroy(job1.id, function(err) {
          if (err) return done(err);
          if (err) return done(err);
          cat.links.should.have.length(1);
          done();
        });
      });
    });

    it('should find items on scope', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(1);
        cat.items.at(0).id.should.eql(job2.id);
        cat.items.at(0).name.should.equal(job2.name);

        // lazy-loaded relations
        should.not.exist(cat.items.at(0).job());

        cat.items(function(err, items) {
          if (err) return done(err);
          cat.items.at(0).job().should.be.instanceof(Job);
          cat.items.at(0).job().name.should.equal('Job 2');
          done();
        });
      });
    });

    it('should add related items to scope', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(1);
        cat.items.add(job3, function(err, link) {
          if (err) return done(err);
          link.should.be.instanceof(Link);
          link.id.should.eql(job3.id);
          link.name.should.equal('Job 3');

          cat.links.should.have.length(2);
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find items on scope', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(2);

        cat.items.at(0).should.be.instanceof(Link);
        cat.items.at(0).id.should.eql(job2.id);
        cat.items.at(0).name.should.equal(job2.name);
        cat.items.at(1).id.should.eql(job3.id);
        cat.items.at(1).name.should.equal(job3.name);

        done();
      });
    });

    it('should remove embedded items by reference id', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(2);
        cat.items.remove(job2.id, function(err) {
          if (err) return done(err);
          if (err) return done(err);
          cat.links.should.have.length(1);
          done();
        });
      });
    });

    it('should have removed embedded items by reference id', function(done) {
      Category.findOne(function(err, cat) {
        if (err) return done(err);
        cat.links.should.have.length(1);
        done();
      });
    });

    let jobId;

    it('should create items on scope', function(done) {
      Category.create({name: 'Category B'}, function(err, cat) {
        if (err) return done(err);
        category = cat;
        const link = cat.items.build({notes: 'Some notes...'});
        link.job.create({name: 'Job 1'}, function(err, p) {
          if (err) return done(err);
          jobId = p.id;
          cat.links[0].id.should.eql(p.id);
          cat.links[0].name.should.equal('Job 1'); // denormalized
          cat.links[0].notes.should.equal('Some notes...');
          cat.items.at(0).should.equal(cat.links[0]);
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find items on scope', function(done) {
      Category.findById(category.id, function(err, cat) {
        if (err) return done(err);
        cat.name.should.equal('Category B');
        cat.links.toObject().should.eql([
          {id: jobId, name: 'Job 1', notes: 'Some notes...'},
        ]);
        cat.items.at(0).should.equal(cat.links[0]);
        cat.items(function(err, items) { // alternative access
          if (err) return done(err);
          items.should.be.an.array;
          items.should.have.length(1);
          items[0].job(function(err, p) {
            p.name.should.equal('Job 1'); // actual value
            done();
          });
        });
      });
    });

    it('should update items on scope - and save parent', function(done) {
      Category.findById(category.id, function(err, cat) {
        if (err) return done(err);
        const link = cat.items.at(0);
        // use 'updateById' instead as a replacement as it is one of the embedsMany methods,
        // that works with all connectors. `updateAttributes` does not recognize the query done on
        // the Category Model, resulting with an error in three connectors: mssql, oracle, postgresql
        cat.items.updateById(link.id, {notes: 'Updated notes...'}, function(err, link) {
          if (err) return done(err);
          link.notes.should.equal('Updated notes...');
          done();
        });
      });
    });

    it('should find items on scope - verify update', function(done) {
      Category.findById(category.id, function(err, cat) {
        if (err) return done(err);
        cat.name.should.equal('Category B');
        cat.links.toObject().should.eql([
          {id: jobId, name: 'Job 1', notes: 'Updated notes...'},
        ]);
        done();
      });
    });

    it('should remove items from scope - and save parent', function(done) {
      Category.findById(category.id, function(err, cat) {
        if (err) return done(err);
        cat.items.at(0).destroy(function(err, link) {
          if (err) return done(err);
          cat.links.should.have.lengthOf(0);
          done();
        });
      });
    });

    it('should find items on scope - verify destroy', function(done) {
      Category.findById(category.id, function(err, cat) {
        if (err) return done(err);
        cat.name.should.equal('Category B');
        cat.links.should.have.lengthOf(0);
        done();
      });
    });
  });

  describe('embedsMany - polymorphic relations', function() {
    let person1, person2;

    before(function(done) {
      tmp = getTransientDataSource();

      Book = db.define('Book', {name: String});
      Author = db.define('Author', {name: String});
      Reader = db.define('Reader', {name: String});

      Link = tmp.define('Link', {
        id: {type: Number, id: true},
        name: String, notes: String,
      }); // generic model
      Link.validatesPresenceOf('linkedId');
      Link.validatesPresenceOf('linkedType');

      db.automigrate(['Book', 'Author', 'Reader'], done);
    });

    it('can be declared', function(done) {
      const idType = db.connector.getDefaultIdType();

      Book.embedsMany(Link, {as: 'people',
        polymorphic: 'linked',
        scope: {include: 'linked'},
      });
      Link.belongsTo('linked', {
        polymorphic: {idType: idType}, // native type
        properties: {name: 'name'}, // denormalized
        options: {invertProperties: true},
      });
      db.automigrate(['Book', 'Author', 'Reader'], done);
    });

    it('should setup related items', function(done) {
      Author.create({name: 'Author 1'}, function(err, p) {
        person1 = p;
        Reader.create({name: 'Reader 1'}, function(err, p) {
          person2 = p;
          done();
        });
      });
    });

    it('should create items on scope', function(done) {
      Book.create({name: 'Book'}, function(err, book) {
        let link = book.people.build({notes: 'Something ...'});
        link.linked(person1);
        link = book.people.build();
        link.linked(person2);
        book.save(function(err, book) {
          if (err) return done(err);

          let link = book.people.at(0);
          link.should.be.instanceof(Link);
          link.id.should.equal(1);
          link.linkedId.should.eql(person1.id);
          link.linkedType.should.equal('Author');
          link.name.should.equal('Author 1');

          link = book.people.at(1);
          link.should.be.instanceof(Link);
          link.id.should.equal(2);
          link.linkedId.should.eql(person2.id);
          link.linkedType.should.equal('Reader');
          link.name.should.equal('Reader 1');

          done();
        });
      });
    });

    it('should include related items on scope', function(done) {
      Book.findOne(function(err, book) {
        book.links.should.have.length(2);

        let link = book.people.at(0);
        link.should.be.instanceof(Link);
        link.id.should.eql(1);
        link.linkedId.should.eql(person1.id);
        link.linkedType.should.equal('Author');
        link.notes.should.equal('Something ...');

        link = book.people.at(1);
        link.should.be.instanceof(Link);
        link.id.should.eql(2);
        link.linkedId.should.eql(person2.id);
        link.linkedType.should.equal('Reader');

        // lazy-loaded relations
        should.not.exist(book.people.at(0).linked());
        should.not.exist(book.people.at(1).linked());

        book.people(function(err, people) {
          people[0].linked().should.be.instanceof(Author);
          people[0].linked().name.should.equal('Author 1');
          people[1].linked().should.be.instanceof(Reader);
          people[1].linked().name.should.equal('Reader 1');
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.supportInclude === true,
      'should include nested related items on scope', function(done) {
      // There's some date duplication going on, so it might
      // make sense to override toObject on a case-by-case basis
      // to sort this out (delete links, keep people).
      // In loopback, an afterRemote filter could do this as well.

        Book.find({include: 'people'}, function(err, books) {
          const obj = books[0].toObject();

          obj.should.have.property('links');
          obj.should.have.property('people');

          obj.links.should.have.length(2);
          obj.links[0].name.should.be.oneOf('Author 1', 'Reader 1');
          obj.links[1].name.should.be.oneOf('Author 1', 'Reader 1');

          obj.people.should.have.length(2);

          obj.people[0].name.should.equal('Author 1');
          obj.people[0].notes.should.equal('Something ...');

          obj.people[0].linked.name.should.equal('Author 1');
          obj.people[1].linked.name.should.equal('Reader 1');

          done();
        });
      });
  });

  describe('referencesMany', function() {
    let job1, job2, job3;

    before(function(done) {
      Category = db.define('Category', {name: String});
      Job = db.define('Job', {name: String});

      db.automigrate(['Job', 'Category'], done);
    });

    it('can be declared', function(done) {
      const reverse = function(cb) {
        cb = cb || createPromiseCallback();
        const modelInstance = this.modelInstance;
        const fk = this.definition.keyFrom;
        const ids = modelInstance[fk] || [];
        modelInstance.updateAttribute(fk, ids.reverse(), function(err, inst) {
          cb(err, inst[fk] || []);
        });
        return cb.promise;
      };

      reverse.shared = true; // remoting
      reverse.http = {verb: 'put', path: '/jobs/reverse'};

      Category.referencesMany(Job, {scopeMethods: {
        reverse: reverse,
      }});

      Category.prototype['__reverse__jobs'].should.be.a.function;
      should.exist(Category.prototype['__reverse__jobs'].shared);
      Category.prototype['__reverse__jobs'].http.should.eql(reverse.http);

      db.automigrate(['Job', 'Category'], done);
    });

    it('should setup test records', function(done) {
      Job.create({name: 'Job 1'}, function(err, p) {
        job1 = p;
        Job.create({name: 'Job 3'}, function(err, p) {
          job3 = p;
          done();
        });
      });
    });

    it('should create record on scope', function(done) {
      Category.create({name: 'Category A'}, function(err, cat) {
        cat.jobIds.should.be.an.array;
        cat.jobIds.should.have.length(0);
        cat.jobs.create({name: 'Job 2'}, function(err, p) {
          if (err) return done(err);
          cat.jobIds.should.have.lengthOf(1);
          cat.jobIds[0].should.eql(p.id);
          p.name.should.equal('Job 2');
          job2 = p;
          done();
        });
      });
    });

    it('should not allow duplicate record on scope', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobIds = [job2.id, job2.id];
        cat.save(function(err, p) {
          should.exist(err);
          err.name.should.equal('ValidationError');
          err.details.codes.jobs.should.eql(['uniqueness']);
          done();
        });
      });
    });

    it('should find items on scope', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobIds.should.have.lengthOf(1);
        cat.jobIds[0].should.eql(job2.id);
        cat.jobs(function(err, jobs) {
          if (err) return done(err);
          const p = jobs[0];
          p.id.should.eql(job2.id);
          p.name.should.equal('Job 2');
          done();
        });
      });
    });

    it('should find items on scope - findById', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobIds.should.have.lengthOf(1);
        cat.jobIds[0].should.eql(job2.id);
        cat.jobs.findById(job2.id, function(err, p) {
          if (err) return done(err);
          p.should.be.instanceof(Job);
          p.id.should.eql(job2.id);
          p.name.should.equal('Job 2');
          done();
        });
      });
    });

    it('should check if a record exists on scope', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.exists(job2.id, function(err, exists) {
          if (err) return done(err);
          should.exist(exists);
          done();
        });
      });
    });

    it('should update a record on scope', function(done) {
      Category.findOne(function(err, cat) {
        const attrs = {name: 'Job 2 - edit'};
        cat.jobs.updateById(job2.id, attrs, function(err, p) {
          if (err) return done(err);
          p.name.should.equal(attrs.name);
          done();
        });
      });
    });

    it('should get a record by index - at', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.at(0, function(err, p) {
          if (err) return done(err);
          p.should.be.instanceof(Job);
          p.id.should.eql(job2.id);
          p.name.should.equal('Job 2 - edit');
          done();
        });
      });
    });

    it('should add a record to scope - object', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.add(job1, function(err, prod) {
          if (err) return done(err);
          cat.jobIds[0].should.eql(job2.id);
          cat.jobIds[1].should.eql(job1.id);
          prod.id.should.eql(job1.id);
          prod.should.have.property('name');
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should add a record to scope - object', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.add(job3.id, function(err, prod) {
          if (err) return done(err);
          const expected = [job2.id, job1.id, job3.id];
          cat.jobIds[0].should.eql(expected[0]);
          cat.jobIds[1].should.eql(expected[1]);
          cat.jobIds[2].should.eql(expected[2]);
          prod.id.should.eql(job3.id);
          prod.should.have.property('name');
          done();
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find items on scope - findById', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.findById(job3.id, function(err, p) {
          if (err) return done(err);
          p.id.should.eql(job3.id);
          p.name.should.equal('Job 3');
          done();
        });
      });
    });

    it('should find items on scope - filter', function(done) {
      Category.findOne(function(err, cat) {
        const filter = {where: {name: 'Job 1'}};
        cat.jobs(filter, function(err, jobs) {
          if (err) return done(err);
          jobs.should.have.length(1);
          const p = jobs[0];
          p.id.should.eql(job1.id);
          p.name.should.equal('Job 1');
          done();
        });
      });
    });

    it('should remove items from scope', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.remove(job1.id, function(err, ids) {
          if (err) return done(err);
          const expected = [job2.id, job3.id];
          cat.jobIds[0].should.eql(expected[0]);
          cat.jobIds[1].should.eql(expected[1]);
          cat.jobIds[0].should.eql(ids[0]);
          cat.jobIds[1].should.eql(ids[1]);
          done();
        });
      });
    });

    it('should find items on scope - verify', function(done) {
      Category.findOne(function(err, cat) {
        const expected = [job2.id, job3.id];
        cat.jobIds[0].should.eql(expected[0]);
        cat.jobIds[1].should.eql(expected[1]);
        cat.jobs(function(err, jobs) {
          if (err) return done(err);
          jobs.should.have.length(2);
          jobs[0].id.should.eql(job2.id);
          jobs[1].id.should.eql(job3.id);
          done();
        });
      });
    });

    bdd.itIf(connectorCapabilities.adhocSort !== false,
      'should find items on scope and ordered them by name DESC', function(done) {
        Category.find(function(err, categories) {
          categories.should.have.length(1);
          categories[0].jobs({order: 'name DESC'}, function(err, jobs) {
            if (err) return done(err);
            jobs.should.have.length(2);
            jobs[0].id.should.eql(job3.id);
            jobs[1].id.should.eql(job2.id);
            done();
          });
        });
      });

    bdd.itIf(connectorCapabilities.adhocSort !== false,
      'should allow custom scope methods - reverse', function(done) {
        Category.findOne(function(err, cat) {
          cat.jobs.reverse(function(err, ids) {
            const expected = [job3.id, job2.id];
            ids.toArray().should.eql(expected);
            cat.jobIds.toArray().should.eql(expected);
            done();
          });
        });
      });

    bdd.itIf(connectorCapabilities.adhocSort === false,
      'should allow custom scope methods - reverse', function(done) {
        Category.findOne(function(err, cat) {
          cat.jobs.reverse(function(err, ids) {
            const expected = [job3.id, job2.id];
            ids[0].should.be.oneOf(expected);
            ids[1].should.be.oneOf(expected);
            cat.jobIds[0].should.be.oneOf(expected);
            cat.jobIds[1].should.be.oneOf(expected);
            done();
          });
        });
      });

    bdd.itIf(connectorCapabilities.supportInclude === true,
      'should include related items from scope', function(done) {
        Category.find({include: 'jobs'}, function(err, categories) {
          categories.should.have.length(1);
          const cat = categories[0].toObject();
          cat.name.should.equal('Category A');
          cat.jobs.should.have.length(2);
          cat.jobs[0].id.should.eql(job3.id);
          cat.jobs[1].id.should.eql(job2.id);
          done();
        });
      });

    it('should destroy items from scope - destroyById', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobs.destroy(job2.id, function(err) {
          if (err) return done(err);
          cat.jobIds.should.have.lengthOf(1);
          cat.jobIds[0].should.eql(job3.id);
          Job.exists(job2.id, function(err, exists) {
            if (err) return done(err);
            should.exist(exists);
            exists.should.be.false;
            done();
          });
        });
      });
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find items on scope - verify', function(done) {
      Category.findOne(function(err, cat) {
        cat.jobIds.should.have.lengthOf(1);
        cat.jobIds[0].should.eql(job3.id);
        cat.jobs(function(err, jobs) {
          if (err) return done(err);
          jobs.should.have.length(1);
          jobs[0].id.should.eql(job3.id);
          done();
        });
      });
    });

    it('should setup test records with promises', function(done) {
      db.automigrate(['Job', 'Category'], function() {
        return Job.create({name: 'Job 1'})
          .then(function(p) {
            job1 = p;
            return Job.create({name: 'Job 3'});
          })
          .then(function(p) {
            job3 = p;
            done();
          }).catch(done);
      });
    });

    it('should create record on scope with promises', function(done) {
      Category.create({name: 'Category A'})
        .then(function(cat) {
          cat.jobIds.should.be.an.array;
          cat.jobIds.should.have.length(0);
          return cat.jobs.create({name: 'Job 2'})
            .then(function(p) {
              cat.jobIds.should.have.length(1);
              cat.jobIds[0].should.eql(p.id);
              p.name.should.equal('Job 2');
              job2 = p;
              done();
            });
        }).catch(done);
    });

    it('should not allow duplicate record on scope with promises', function(done) {
      Category.findOne()
        .then(function(cat) {
          cat.jobIds = [job2.id, job2.id];
          return cat.save();
        })
        .then(
          function(p) { done(new Error('save() should have failed')); },
          function(err) {
            err.name.should.equal('ValidationError');
            err.details.codes.jobs.should.eql(['uniqueness']);
            done();
          },
        );
    });

    bdd.itIf(connectorCapabilities.adhocSort !== false,
      'should find items on scope with promises', function(done) {
        Category.findOne()
          .then(function(cat) {
            cat.jobIds.toArray().should.eql([job2.id]);
            return cat.jobs.find();
          })
          .then(function(jobs) {
            const p = jobs[0];
            p.id.should.eql(job2.id);
            p.name.should.equal('Job 2');
            done();
          })
          .catch(done);
      });

    bdd.itIf(connectorCapabilities.adhocSort === false,
      'should find items on scope with promises', function(done) {
        const theExpectedIds = [job1.id, job2.id, job3.id];
        const theExpectedNames = ['Job 1', 'Job 2', 'Job 3'];
        Category.findOne()
          .then(function(cat) {
            cat.jobIds[0].should.be.oneOf(theExpectedIds);
            return cat.jobs.find();
          })
          .then(function(jobs) {
            const p = jobs[0];
            p.id.should.be.oneOf(theExpectedIds);
            p.name.should.be.oneOf(theExpectedNames);
            done();
          })
          .catch(done);
      });

    it('should find items on scope with promises - findById', function(done) {
      Category.findOne()
        .then(function(cat) {
          cat.jobIds.should.have.lengthOf(1);
          cat.jobIds[0].should.eql(job2.id);
          return cat.jobs.findById(job2.id);
        })
        .then(function(p) {
          p.should.be.instanceof(Job);
          p.id.should.eql(job2.id);
          p.name.should.equal('Job 2');
          done();
        })
        .catch(done);
    });

    it('should check if a record exists on scope with promises', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.exists(job2.id)
            .then(function(exists) {
              should.exist(exists);
              done();
            });
        }).catch(done);
    });

    it('should update a record on scope with promises', function(done) {
      Category.findOne()
        .then(function(cat) {
          const attrs = {name: 'Job 2 - edit'};
          return cat.jobs.updateById(job2.id, attrs)
            .then(function(p) {
              p.name.should.equal(attrs.name);
              done();
            });
        })
        .catch(done);
    });

    it('should get a record by index with promises - at', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.at(0);
        })
        .then(function(p) {
          p.should.be.instanceof(Job);
          p.id.should.eql(job2.id);
          p.name.should.equal('Job 2 - edit');
          done();
        })
        .catch(done);
    });

    it('should add a record to scope with promises - object', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.add(job1)
            .then(function(prod) {
              const expected = [job2.id, job1.id];
              cat.jobIds.should.have.lengthOf(expected.length);
              cat.jobIds.should.containDeep(expected);
              prod.id.should.eql(job1.id);
              prod.should.have.property('name');
              done();
            });
        })
        .catch(done);
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should add a record to scope with promises - object', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.add(job3.id)
            .then(function(prod) {
              const expected = [job2.id, job1.id, job3.id];
              cat.jobIds.should.have.lengthOf(expected.length);
              cat.jobIds.should.containDeep(expected);
              prod.id.should.eql(job3.id);
              prod.should.have.property('name');
              done();
            });
        })
        .catch(done);
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find items on scope with promises - findById', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.findById(job3.id);
        })
        .then(function(p) {
          p.id.should.eql(job3.id);
          p.name.should.equal('Job 3');
          done();
        })
        .catch(done);
    });

    it('should find items on scope with promises - filter', function(done) {
      Category.findOne()
        .then(function(cat) {
          const filter = {where: {name: 'Job 1'}};
          return cat.jobs.find(filter);
        })
        .then(function(jobs) {
          jobs.should.have.length(1);
          const p = jobs[0];
          p.id.should.eql(job1.id);
          p.name.should.equal('Job 1');
          done();
        })
        .catch(done);
    });

    it('should remove items from scope with promises', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.remove(job1.id)
            .then(function(ids) {
              const expected = [job2.id, job3.id];
              cat.jobIds.should.have.lengthOf(expected.length);
              cat.jobIds.should.containDeep(expected);
              cat.jobIds.should.eql(ids);
              done();
            });
        })
        .catch(done);
    });

    it('should find items on scope with promises - verify', function(done) {
      Category.findOne()
        .then(function(cat) {
          const expected = [job2.id, job3.id];
          cat.jobIds.should.have.lengthOf(expected.length);
          cat.jobIds.should.containDeep(expected);
          return cat.jobs.find();
        })
        .then(function(jobs) {
          jobs.should.have.length(2);
          jobs[0].id.should.eql(job2.id);
          jobs[1].id.should.eql(job3.id);
          done();
        })
        .catch(done);
    });

    bdd.itIf(connectorCapabilities.adhocSort !== false,
      'should find items on scope and ordered them by name DESC', function(done) {
        Category.find()
          .then(function(categories) {
            categories.should.have.length(1);
            return categories[0].jobs.find({order: 'name DESC'});
          })
          .then(function(jobs) {
            jobs.should.have.length(2);
            jobs[0].id.should.eql(job3.id);
            jobs[1].id.should.eql(job2.id);
            done();
          })
          .catch(done);
      });

    bdd.itIf(connectorCapabilities.adhocSort !== false,
      'should allow custom scope methods with promises - reverse', function(done) {
        Category.findOne()
          .then(function(cat) {
            return cat.jobs.reverse()
              .then(function(ids) {
                const expected = [job3.id, job2.id];
                ids.toArray().should.eql(expected);
                cat.jobIds.toArray().should.eql(expected);
                done();
              });
          })
          .catch(done);
      });

    bdd.itIf(connectorCapabilities.adhocSort === true &&
    connectorCapabilities.supportInclude === true,
    'should include related items from scope with promises', function(done) {
      Category.find({include: 'jobs'})
        .then(function(categories) {
          categories.should.have.length(1);
          const cat = categories[0].toObject();
          cat.name.should.equal('Category A');
          cat.jobs.should.have.length(2);
          cat.jobs[0].id.should.eql(job3.id);
          cat.jobs[1].id.should.eql(job2.id);
          done();
        }).catch(done);
    });

    it('should destroy items from scope with promises - destroyById', function(done) {
      Category.findOne()
        .then(function(cat) {
          return cat.jobs.destroy(job2.id)
            .then(function() {
              const expected = [job3.id];
              if (connectorCapabilities.adhocSort !== false) {
                cat.jobIds.toArray().should.eql(expected);
              } else {
                cat.jobIds.toArray().should.containDeep(expected);
              }
              return Job.exists(job2.id);
            })
            .then(function(exists) {
              should.exist(exists);
              exists.should.be.false;
              done();
            });
        })
        .catch(done);
    });

    // eslint-disable-next-line mocha/no-identical-title
    it('should find items on scope with promises - verify', function(done) {
      Category.findOne()
        .then(function(cat) {
          const expected = [job3.id];
          cat.jobIds.should.have.lengthOf(expected.length);
          cat.jobIds.should.containDeep(expected);
          return cat.jobs.find();
        })
        .then(function(jobs) {
          jobs.should.have.length(1);
          jobs[0].id.should.eql(job3.id);
          done();
        })
        .catch(done);
    });
  });

  describe('custom relation/scope methods', function() {
    let categoryId;

    before(function(done) {
      Category = db.define('Category', {name: String});
      Job = db.define('Job', {name: String});

      db.automigrate(['Job', 'Category'], done);
    });

    it('can be declared', function(done) {
      const relation = Category.hasMany(Job);

      const summarize = function(cb) {
        cb = cb || createPromiseCallback();
        const modelInstance = this.modelInstance;
        this.fetch(function(err, items) {
          if (err) return cb(err, []);
          const summary = items.map(function(item) {
            const obj = item.toObject();
            obj.categoryName = modelInstance.name;
            return obj;
          });
          cb(null, summary);
        });
        return cb.promise;
      };

      summarize.shared = true; // remoting
      summarize.http = {verb: 'get', path: '/jobs/summary'};

      relation.defineMethod('summarize', summarize);

      Category.prototype['__summarize__jobs'].should.be.a.function;
      should.exist(Category.prototype['__summarize__jobs'].shared);
      Category.prototype['__summarize__jobs'].http.should.eql(summarize.http);

      db.automigrate(['Job', 'Category'], done);
    });

    it('should setup test records', function(done) {
      Category.create({name: 'Category A'}, function(err, cat) {
        categoryId = cat.id;
        cat.jobs.create({name: 'Job 1'}, function(err, p) {
          cat.jobs.create({name: 'Job 2'}, function(err, p) {
            done();
          });
        });
      });
    });

    it('should allow custom scope methods - summarize', function(done) {
      const categoryIdStr = categoryId.toString();
      const expected = [
        {name: 'Job 1', categoryId: categoryIdStr, categoryName: 'Category A'},
        {name: 'Job 2', categoryId: categoryIdStr, categoryName: 'Category A'},
      ];

      Category.findOne(function(err, cat) {
        cat.jobs.summarize(function(err, summary) {
          if (err) return done(err);
          const result = summary.map(function(item) {
            delete item.id;
            item.categoryId = item.categoryId.toString();
            return item;
          });
          // order-independent match
          result.should.containDeep(expected);
          expected.should.containDeep(result);
          done();
        });
      });
    });

    it('should allow custom scope methods with promises - summarize', function(done) {
      const categoryIdStr = categoryId.toString();
      const expected = [
        {name: 'Job 1', categoryId: categoryIdStr, categoryName: 'Category A'},
        {name: 'Job 2', categoryId: categoryIdStr, categoryName: 'Category A'},
      ];

      Category.findOne()
        .then(function(cat) {
          return cat.jobs.summarize();
        })
        .then(function(summary) {
          const result = summary.map(function(item) {
            delete item.id;
            item.categoryId = item.categoryId.toString();
            return item;
          });
          // order-independent match
          result.should.containDeep(expected);
          expected.should.containDeep(result);
          done();
        })
        .catch(done);
    });
  });

  describe('relation names', function() {
    it('throws error when a relation name is `trigger`', function() {
      Chapter = db.define('Chapter', {name: String});

      (function() {
        db.define(
          'Book',
          {name: String},
          {
            relations: {
              trigger: {
                model: 'Chapter',
                type: 'hasMany',
              },
            },
          },
        );
      }).should.throw('Invalid relation name: trigger');
    });
  });

  describe('polymorphic hasMany - revert', function() {
    before(function(done) {
      Picture = db.define('Picture', {name: String});
      Author = db.define('Author', {name: String});
      PictureLink = db.define('PictureLink', {});
      Author.hasMany(Picture, {through: PictureLink, polymorphic: 'imageable', invert: true});
      Picture.hasMany(Author, {through: PictureLink, polymorphic: 'imageable'});
      db.automigrate(['Picture', 'Author', 'PictureLink'], done);
    });
    it('should properly query through an inverted relationship', function(done) {
      Author.create({name: 'Steve'}, function(err, author) {
        if (err) {
          return done(err);
        }
        author.pictures.create({name: 'Steve pic 1'}, function(err, pic) {
          if (err) {
            return done(err);
          }
          Author.findOne({include: 'pictures'}, function(err, author) {
            if (err) {
              return done(err);
            }
            author.pictures().length.should.eql(1);
            author.pictures()[0].name.should.eql('Steve pic 1');
            done();
          });
        });
      });
    });
  });
});