Merge users through the console

app/models/user.rb

@@ -290,6 +290,73 @@ def set_search
     self.search = "#{username || ''} #{first_name || ''} #{last_name || ''}"
   end
 
+  def merge_into(other, force: false)
+    errors.add(:merge, 'User belongs to different institution') if other.institution_id != institution_id && other.institution_id.present? && institution_id.present?
+    errors.add(:merge, 'User has different permissions') if other.permission != permission && !force
+    return false if errors.any?
+
+    transaction do
+      other.permission = permission if (permission == 'staff' && other.permission == 'student') \
+                                    || (permission == 'zeus' && other.permission != 'zeus')
+
+      other.institution_id = institution_id if other.institution_id.nil?
+
+      rights_request.update(user: other) if !rights_request.nil? && other.permission == 'student' && other.rights_request.nil?
+
+      submissions.each { |s| s.update(user: other) }
+      api_tokens.each { |at| at.update(user: other) }
+      events.each { |e| e.update(user: other) }
+      exports.each { |e| e.update(user: other) }
+      notifications.each { |n| n.update(user: other) }
+      annotations.each { |a| a.update(user: other, last_updated_by_id: other.id) }
+      questions.each { |q| q.update(user: other) }
+
+      activity_read_states.each do |ars|
+        if other.activity_read_states.find { |oars| oars.activity_id == ars.activity_id }
+          ars.delete
+        else
+          ars.update(user: other)
+        end
+      end
+
+      identities.each do |i|
+        if other.identities.find { |oi| oi.provider_id == i.provider_id }
+          i.delete
+        else
+          i.update(user: other)
+        end
+      end
+
+      repository_admins.each do |ra|
+        if other.repository_admins.find { |ora| ora.repository_id == ra.repository_id }
+          ra.delete
+        else
+          ra.update(user: other)
+        end
+      end
+
+      course_memberships.each do |cm|
+        other_cm = other.course_memberships.find { |ocm| ocm.course_id == cm.course_id }
+        if other_cm.nil?
+          cm.update(user: other)
+        elsif other_cm.status == cm.status \
+          || other_cm.status == 'course_admin' \
+          || (other_cm.status == 'student' && cm.status != 'course_admin') \
+          || (other_cm.status == 'unsubscribed' && cm.status == 'pending')
+          other_cm.update(favorite: true) if cm.favorite
+          cm.delete
+        else
+          cm.update(favorite: true) if other_cm.favorite
+          other_cm.delete
+          cm.update(user: other)
+        end
+      end
+
+      reload
+      destroy
+    end
+  end
+
   private
 
   def set_token

lib/tasks/merge_users.rake

@@ -0,0 +1,62 @@
+
+task :merge_users, [:arg1, :arg2] => :environment do |task, args|
+  u1_id = args[:arg1].to_i
+  u2_id = args[:arg2].to_i
+
+  MergeUsers.new.merge_users_interactive u1_id, u2_id
+end
+
+class MergeUsers
+  LABEL_WIDTH = 20
+  USER_WIDTH = 50
+
+  def initialize(input = $stdin, output = $stdout)
+    @input = input
+    @output = output
+  end
+
+  def print_users(*users)
+    @output.puts 'Username: '.ljust(LABEL_WIDTH) + users.map { |u| u.username.to_s.ljust(USER_WIDTH) }.join
+    @output.puts 'Email: '.ljust(LABEL_WIDTH) + users.map { |u| u.email.to_s.ljust(USER_WIDTH) }.join
+    @output.puts 'Name: '.ljust(LABEL_WIDTH) + users.map { |u| u.full_name.to_s.ljust(USER_WIDTH) }.join
+    @output.puts 'Permission: '.ljust(LABEL_WIDTH) + users.map { |u| u.permission.to_s.ljust(USER_WIDTH) }.join
+
+    @output.puts 'Courses: '.ljust(LABEL_WIDTH) + users.map { |u| u.courses.count.to_s.ljust(USER_WIDTH) }.join
+    @output.puts 'Submissions: '.ljust(LABEL_WIDTH) + users.map { |u| u.submissions.count.to_s.ljust(USER_WIDTH) }.join
+    @output.puts 'Read states: '.ljust(LABEL_WIDTH) + users.map { |u| u.activity_read_states.count.to_s.ljust(USER_WIDTH) }.join
+    @output.puts 'Repositories: '.ljust(LABEL_WIDTH) + users.map { |u| u.repositories.count.to_s.ljust(USER_WIDTH) }.join
+  end
+
+  def merge_users_interactive(u1_id, u2_id)
+    u1 = User.find(u1_id)
+    u2 = User.find(u2_id)
+
+    print_users u1, u2
+
+    @output.puts ''
+
+    c = ''
+    until %W[\r \n y n f].include? c
+      u1, u2 = u2, u1 if c == 's'
+      @output.puts "Invalid input #{c}" unless ['s', ''].include?(c)
+      @output.puts "Are you sure you want to merge #{u1.username} into #{u2.username}? (y)es|(N)o|(f)orce|(s)wap"
+      c = @input.getch.downcase
+    end
+
+    @output.puts ''
+
+    if %W[\r \n n].include? c
+      @output.puts 'Merge cancelled'
+      return
+    end
+
+    success = u1.merge_into(u2, force: c == 'f')
+    if success
+      @output.puts "Successfully merged #{u1.username} into #{u2.username}"
+      print_users u2
+    else
+      @output.puts 'Merge failed'
+      @output.puts u1.errors.full_messages.join('\n')
+    end
+  end
+end

test/models/user_test.rb

@@ -365,4 +365,171 @@ def setup
     @user.subscribed_courses.first.update(year: '2')
     assert_equal [@user.subscribed_courses.first], @user.drawer_courses
   end
+
+  test 'user should be removed after merge' do
+    u1 = create :user
+    u2 = create :user
+    u1.merge_into(u2)
+
+    assert_not u1.persisted?
+  end
+
+  test 'merge should fail if institutions are different' do
+    i1 = create :institution
+    i2 = create :institution
+    u1 = create :user, institution: i1
+    u2 = create :user, institution: i2
+
+    result = u1.merge_into(u2)
+
+    assert_not result
+    assert u1.persisted?
+  end
+
+  test 'merge should succeed if only one institution is set' do
+    i1 = create :institution
+    u1 = create :user, institution: i1
+    u2 = create :user
+
+    result = u1.merge_into(u2)
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal i1, u2.institution
+  end
+
+  test 'merge should fail if permissions are different' do
+    u1 = create :user, permission: 'student'
+    u2 = create :user, permission: 'staff'
+
+    result = u1.merge_into(u2)
+
+    assert_not result
+    assert u1.persisted?
+  end
+
+  test 'merge should take highest permission if force is used' do
+    u1 = create :user, permission: 'zeus'
+    u2 = create :user, permission: 'staff'
+
+    result = u1.merge_into(u2, force: true)
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal 'zeus', u2.permission
+  end
+
+  test 'merge should transfer all associated objects to the other user' do
+    u1 = create :user
+    u2 = create :user
+
+    [u1, u2].each do |u|
+      c = create :course
+      s = create :submission, user: u, course: c
+      create :api_token, user: u
+      create :event, user: u
+      create :export, user: u
+      create :notification, user: u
+      create :annotation, user: u, submission: s
+      create :question, submission: s
+    end
+
+    result = u1.merge_into(u2)
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal 2, u2.submissions.count
+    assert_equal 2, u2.api_tokens.count
+    assert_equal 2, u2.events.count
+    assert_equal 2, u2.exports.count
+    assert_equal 4, u2.notifications.count
+    assert_equal 4, u2.annotations.count
+    assert_equal 2, u2.questions.count
+  end
+
+  test 'merge should only transfer unique read states to the other user' do
+    u1 = create :user
+    u2 = create :user
+
+    a1 = create :content_page
+    a2 = create :content_page
+    create :activity_read_state, user: u1, activity: a1
+    create :activity_read_state, user: u2, activity: a1
+    create :activity_read_state, user: u1, activity: a2
+
+    result = u1.merge_into(u2)
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal 2, u2.activity_read_states.count
+  end
+
+  test 'merge should only transfer unique identities to the other user' do
+    u1 = create :user
+    u2 = create :user
+
+    p1 = create :provider
+    p2 = create :provider
+    Identity.create user: u1, provider: p1, identifier: 'a'
+    Identity.create user: u2, provider: p1, identifier: 'b'
+    Identity.create user: u1, provider: p2, identifier: 'c'
+
+    result = u1.merge_into(u2)
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal 2, u2.identities.count
+  end
+
+  test 'merge should only transfer unique repositories to the other user' do
+    u1 = create :user
+    u2 = create :user
+
+    r1 = create :repository, :git_stubbed
+    r2 = create :repository, :git_stubbed
+    RepositoryAdmin.create user: u1, repository: r1
+    RepositoryAdmin.create user: u2, repository: r1
+    RepositoryAdmin.create user: u1, repository: r2
+
+    result = u1.merge_into(u2)
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal 2, u2.repository_admins.count
+  end
+
+  test 'merge should transfer course membership with most rights to the other user' do
+    u1 = create :user
+    u2 = create :user
+
+    c1 = create :course
+    c2 = create :course
+    c3 = create :course
+    c4 = create :course
+    c5 = create :course
+    CourseMembership.create user: u1, course: c1, status: 'student', favorite: true
+    CourseMembership.create user: u1, course: c2, status: 'pending'
+    CourseMembership.create user: u1, course: c3, status: 'unsubscribed'
+    CourseMembership.create user: u1, course: c4, status: 'student'
+    CourseMembership.create user: u1, course: c5, status: 'course_admin'
+
+    CourseMembership.create user: u2, course: c2, status: 'pending'
+    CourseMembership.create user: u2, course: c3, status: 'course_admin', favorite: true
+    CourseMembership.create user: u2, course: c4, status: 'unsubscribed'
+    CourseMembership.create user: u2, course: c5, status: 'student'
+
+    result = u1.merge_into(u2)
+
+    assert_equal 0, u1.course_memberships.count
+
+    assert result
+    assert_not u1.persisted?
+    assert_equal 5, u2.course_memberships.count
+    assert_equal 4, u2.subscribed_courses.count
+    assert_equal 2, u2.favorite_courses.count
+    assert_equal 2, u2.administrating_courses.count
+    assert_equal 2, u2.enrolled_courses.count
+    assert_equal 1, u2.pending_courses.count
+    assert_equal 0, u2.unsubscribed_courses.count
+  end
 end

test/tasks/merge_users_test.rb

@@ -0,0 +1,89 @@
+require 'test_helper'
+require 'stringio'
+require 'rake'
+load './lib/tasks/merge_users.rake'
+
+class MergeUserTest < ActiveSupport::TestCase
+  def stub_stdin(*chars)
+    string_io = StringIO.new
+    chars.each { |c| string_io.print c }
+    string_io.rewind
+    string_io
+  end
+
+  def merge_users_interactive(u1_id, u2_id, *chars)
+    input = stub_stdin(*chars)
+    output = File.open(File::NULL, 'w')
+    MergeUsers.new(input, output).merge_users_interactive(u1_id, u2_id)
+  end
+
+  test 'The script should cancel on no' do
+    u1 = create :user
+    u2 = create :user
+
+    merge_users_interactive u1.id, u2.id, 'n'
+
+    assert User.exists?(u1.id)
+    assert User.exists?(u2.id)
+  end
+
+  test 'The script should cancel on enter' do
+    u1 = create :user
+    u2 = create :user
+
+    merge_users_interactive u1.id, u2.id, '\n'
+
+    assert User.exists?(u1.id)
+    assert User.exists?(u2.id)
+  end
+
+  test 'The script should merge on yes' do
+    u1 = create :user
+    u2 = create :user
+
+    merge_users_interactive u1.id, u2.id, 'y'
+
+    assert_not User.exists?(u1.id)
+    assert User.exists?(u2.id)
+  end
+
+  test 'The script should swap on swap' do
+    u1 = create :user
+    u2 = create :user
+
+    merge_users_interactive u1.id, u2.id, 's', 'y'
+
+    assert User.exists?(u1.id)
+    assert_not User.exists?(u2.id)
+  end
+
+  test 'The script should ignore incorrect input' do
+    u1 = create :user
+    u2 = create :user
+
+    merge_users_interactive u1.id, u2.id, 'a', 'z', 'd', 'y'
+
+    assert_not User.exists?(u1.id)
+    assert User.exists?(u2.id)
+  end
+
+  test 'The script should fail on yes with different permissions' do
+    u1 = create :user, permission: 'student'
+    u2 = create :user, permission: 'zeus'
+
+    merge_users_interactive u1.id, u2.id, 'y'
+
+    assert User.exists?(u1.id)
+    assert User.exists?(u2.id)
+  end
+
+  test 'The script should merge on force  with different permissions' do
+    u1 = create :user, permission: 'student'
+    u2 = create :user, permission: 'zeus'
+
+    merge_users_interactive u1.id, u2.id, 'f'
+
+    assert_not User.exists?(u1.id)
+    assert User.exists?(u2.id)
+  end
+end