Remove assigned_(issues|merge_requests) methods from the issuable

app/helpers/issuables_helper.rb

@@ -194,7 +194,7 @@ module IssuablesHelper
 
   def assigned_issuables_count(assignee, issuable_type, state)
     params = { assignee_id: assignee.id, state: state }
-    Object::const_get("#{issuable_type.to_s.camelize}Finder").new(current_user, params).execute.count
+    Object.const_get("#{issuable_type.to_s.camelize}Finder").new(current_user, params).execute.count
   end
 
   def sidebar_gutter_collapsed?

app/models/user.rb

@@ -99,9 +99,6 @@ class User < ActiveRecord::Base
   has_many :award_emoji,              dependent: :destroy
   has_many :triggers,                 dependent: :destroy, class_name: 'Ci::Trigger', foreign_key: :owner_id
 
-  has_many :assigned_issues,          dependent: :nullify, foreign_key: :assignee_id, class_name: "Issue"
-  has_many :assigned_merge_requests,  dependent: :nullify, foreign_key: :assignee_id, class_name: "MergeRequest"
-
   # Issues that a user owns are expected to be moved to the "ghost" user before
   # the user is destroyed. If the user owns any issues during deletion, this
   # should be treated as an exceptional condition.
@@ -893,13 +890,13 @@ class User < ActiveRecord::Base
 
   def assigned_open_merge_request_count(force: false)
     Rails.cache.fetch(['users', id, 'assigned_open_merge_request_count'], force: force) do
-      assigned_merge_requests.opened.count
+      MergeRequestsFinder.new(self, assignee_id: self.id, state: 'opened').execute.count
     end
   end
 
   def assigned_open_issues_count(force: false)
     Rails.cache.fetch(['users', id, 'assigned_open_issues_count'], force: force) do
-      assigned_issues.opened.count
+      IssuesFinder.new(self, assignee_id: self.id, state: 'opened').execute.count
     end
   end
 

spec/models/user_spec.rb

@@ -24,9 +24,7 @@ describe User, models: true do
     it { is_expected.to have_many(:recent_events).class_name('Event') }
     it { is_expected.to have_many(:issues).dependent(:restrict_with_exception) }
     it { is_expected.to have_many(:notes).dependent(:destroy) }
-    it { is_expected.to have_many(:assigned_issues).dependent(:nullify) }
     it { is_expected.to have_many(:merge_requests).dependent(:destroy) }
-    it { is_expected.to have_many(:assigned_merge_requests).dependent(:nullify) }
     it { is_expected.to have_many(:identities).dependent(:destroy) }
     it { is_expected.to have_many(:spam_logs).dependent(:destroy) }
     it { is_expected.to have_many(:todos).dependent(:destroy) }

spec/services/members/authorized_destroy_service_spec.rb

 require 'spec_helper'
 
 describe Members::AuthorizedDestroyService, services: true do
-  let(:user) { create(:user) }
   let(:member_user) { create(:user) }
   let(:project) { create(:empty_project, :public) }
   let(:group) { create(:group, :public) }
   let(:group_project) { create(:empty_project, :public, group: group) }
 
   def number_of_assigned_issuables(user)
-    user.assigned_issues.count + user.assigned_merge_requests.count
+    Issue.assigned_to(user).count + MergeRequest.assigned_to(user).count
   end
 
   context 'Group member' do