1 files changed, 114 insertions, 0 deletions
diff --git a/spec/services/merge_requests/handle_assignees_change_service_spec.rb b/spec/services/merge_requests/handle_assignees_change_service_spec.rb
new file mode 100644
index 00000000000..cc595aab04b
--- /dev/null
+++ b/spec/services/merge_requests/handle_assignees_change_service_spec.rb
@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe MergeRequests::HandleAssigneesChangeService do
+  let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:assignee) { create(:user) }
+  let_it_be(:merge_request) { create(:merge_request, author: user, source_project: project, assignees: [assignee]) }
+  let_it_be(:old_assignees) { create_list(:user, 3) }
+
+  let(:options) { {} }
+  let(:service) { described_class.new(project, user) }
+
+  before_all do
+    project.add_maintainer(user)
+    project.add_developer(assignee)
+
+    old_assignees.each do |old_assignee|
+      project.add_developer(old_assignee)
+    end
+  end
+
+  describe '#async_execute' do
+    def async_execute
+      service.async_execute(merge_request, old_assignees, options)
+    end
+
+    it 'performs MergeRequests::HandleAssigneesChangeWorker asynchronously' do
+      expect(MergeRequests::HandleAssigneesChangeWorker)
+        .to receive(:perform_async)
+        .with(
+          merge_request.id,
+          user.id,
+          old_assignees.map(&:id),
+          options
+        )
+
+      async_execute
+    end
+
+    context 'when async_handle_merge_request_assignees_change feature is disabled' do
+      before do
+        stub_feature_flags(async_handle_merge_request_assignees_change: false)
+      end
+
+      it 'calls #execute' do
+        expect(service).to receive(:execute).with(merge_request, old_assignees, options)
+
+        async_execute
+      end
+    end
+  end
+
+  describe '#execute' do
+    def execute
+      service.execute(merge_request, old_assignees, options)
+    end
+
+    it 'creates assignee note' do
+      execute
+
+      note = merge_request.notes.last
+
+      expect(note).not_to be_nil
+      expect(note.note).to include "assigned to #{assignee.to_reference} and unassigned #{old_assignees.map(&:to_reference).to_sentence}"
+    end
+
+    it 'sends email notifications to old and new assignees', :mailer, :sidekiq_inline do
+      perform_enqueued_jobs do
+        execute
+      end
+
+      should_email(assignee)
+      old_assignees.each do |old_assignee|
+        should_email(old_assignee)
+      end
+    end
+
+    it 'creates pending todo for assignee' do
+      execute
+
+      todo = assignee.todos.last
+
+      expect(todo).to be_pending
+    end
+
+    it 'tracks users assigned event' do
+      expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+        .to receive(:track_users_assigned_to_mr).once.with(users: [assignee])
+
+      execute
+    end
+
+    it 'tracks assignees changed event' do
+      expect(Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter)
+        .to receive(:track_assignees_changed_action).once.with(user: user)
+
+      execute
+    end
+
+    context 'when execute_hooks option is set to true' do
+      let(:options) { { execute_hooks: true } }
+
+      it 'execute hooks and services' do
+        expect(merge_request.project).to receive(:execute_hooks).with(anything, :merge_request_hooks)
+        expect(merge_request.project).to receive(:execute_services).with(anything, :merge_request_hooks)
+        expect(service).to receive(:enqueue_jira_connect_messages_for).with(merge_request)
+
+        execute
+      end
+    end
+  end
+end