Fix hard-deleting users when they have authored issues

app/models/user.rb

@@ -101,6 +101,7 @@ class User < ActiveRecord::Base
 
   has_many :snippets,                 dependent: :destroy, foreign_key: :author_id
   has_many :notes,                    dependent: :destroy, foreign_key: :author_id
+  has_many :issues,                   dependent: :destroy, foreign_key: :author_id
   has_many :merge_requests,           dependent: :destroy, foreign_key: :author_id
   has_many :events,                   dependent: :destroy, foreign_key: :author_id
   has_many :subscriptions,            dependent: :destroy
@@ -120,11 +121,6 @@ class User < ActiveRecord::Base
   has_many :assigned_issues, class_name: "Issue", through: :issue_assignees, source: :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.
-  has_many :issues,                   dependent: :restrict_with_exception, foreign_key: :author_id
-
   #
   # Validations
   #

changelogs/unreleased/33215-fix-hard-delete-of-users.yml

+---
+title: Fix hard-deleting users when they have authored issues
+merge_request: 11855
+author:

spec/models/user_spec.rb

@@ -22,7 +22,7 @@ describe User, models: true do
     it { is_expected.to have_many(:deploy_keys).dependent(:destroy) }
     it { is_expected.to have_many(:events).dependent(:destroy) }
     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(:issues).dependent(:destroy) }
     it { is_expected.to have_many(:notes).dependent(:destroy) }
     it { is_expected.to have_many(:merge_requests).dependent(:destroy) }
     it { is_expected.to have_many(:identities).dependent(:destroy) }

spec/services/users/destroy_service_spec.rb

@@ -147,16 +147,22 @@ describe Users::DestroyService, services: true do
     end
 
     context "migrating associated records" do
+      let!(:issue)     { create(:issue, author: user) }
+
       it 'delegates to the `MigrateToGhostUser` service to move associated records to the ghost user' do
-        expect_any_instance_of(Users::MigrateToGhostUserService).to receive(:execute).once
+        expect_any_instance_of(Users::MigrateToGhostUserService).to receive(:execute).once.and_call_original
 
         service.execute(user)
+
+        expect(issue.reload.author).to be_ghost
       end
 
       it 'does not run `MigrateToGhostUser` if hard_delete option is given' do
         expect_any_instance_of(Users::MigrateToGhostUserService).not_to receive(:execute)
 
         service.execute(user, hard_delete: true)
+
+        expect(Issue.exists?(issue.id)).to be_falsy
       end
     end
   end