deep population (>4 levels)

[TrejGun]

isn't population work recursively?
i expected to populate 4 levels deep but found out its impossible
the 4th level isn't getting populated

    it.only('4 levels population', function (done) {
      var level4Schema = new Schema({
        name: {type: String}
      });

      var level3Schema = new Schema({
        name: {type: String},
        level4: [{type: Schema.Types.ObjectId, ref: 'level_4'}]
      });

      var level2Schema = new Schema({
        name: {type: String},
        level3: [{type: Schema.Types.ObjectId, ref: 'level_3'}]
      });

      var level1Schema = new Schema({
        name: {type: String},
        level2: [{type: Schema.Types.ObjectId, ref: 'level_2'}]
      });

      var level4 = db.model('level_4', level4Schema);
      var level3 = db.model('level_3', level3Schema);
      var level2 = db.model('level_2', level2Schema);
      var level1 = db.model('level_1', level1Schema);

      level4.create([
        {name: 'level 4'}
      ], function (error, l4) {
        level3.create([
          {name: 'level 3', level4: l4[0]._id}
        ], function (error, l3) {
          assert.ifError(error);
          level2.create([
            {name: 'level 2', level3: l3[0]._id}
          ], function (error, l2) {
            assert.ifError(error);
            console.log(l2)
            level1.create([
              {name: 'level 1', level2: l2[0]._id}
            ], function (error, l1) {
              assert.ifError(error);
              level1.findById(l1[0]._id)
                  .populate({
                    path: 'level2',
                    populate: {
                      path: 'level3',
                      populate: {
                        path: 'level4'
                      }
                    }
                  })
                  .exec(function (error, obj) {
                    assert.ifError(error);
                    var util = require('util');
                    console.log(util.inspect(obj, {depth: 10}));
                    assert.ok(obj);
                    done();
                  });
            });
          });
        });
      });
    });

this should not be a big problem to put code in a function and call it recursively for each next level

[vkarpov15]

Womp. Quite possibly the case, deep populate has a lot of rough edges, as you've noticed. I'll try reproing in a bit.

[vkarpov15]

Another case of not getting the model correctly. As a workaround:

.populate({
                    path: 'level2',
                    populate: {
                      path: 'level3',
                      populate: {
                        path: 'level4', model: 'level_4' // <-- explicitly tell mongoose to use this model
                      }
                    }
                  })

[TrejGun]

great news! thanks
i will tests and report of any problems on my projects

[vkarpov15]

Please do, thanks for finding all the bugs :)