AAP-64221 Fix broken cancel logic with dispatcherd (#16247)

* Fix broken cancel logic with dispatcherd

Update tests for UnifiedJob

Update test assertion

* Further simply cancel path

awx/main/tests/functional/models/test_unified_job.py

@@ -1,5 +1,6 @@
 import itertools
 import pytest
+from uuid import uuid4
 
 # CRUM
 from crum import impersonate
@@ -33,6 +34,64 @@ def test_soft_unique_together(post, project, admin_user):
     assert 'combination already exists' in str(r.data)
 
 
+@pytest.mark.django_db
+class TestJobCancel:
+    """
+    Coverage for UnifiedJob.cancel, focused on interaction with dispatcherd objects.
+    Using mocks for the dispatcherd objects, because tests by default use a no-op broker.
+    """
+
+    def test_cancel_sets_flag_and_clears_start_args(self, mocker):
+        job = Job.objects.create(status='running', name='foo-job', celery_task_id=str(uuid4()), controller_node='foo', start_args='{"secret": "value"}')
+        job.websocket_emit_status = mocker.MagicMock()
+
+        assert job.can_cancel is True
+        assert job.cancel_flag is False
+
+        job.cancel()
+        job.refresh_from_db()
+
+        assert job.cancel_flag is True
+        assert job.start_args == ''
+
+    def test_cancel_sets_job_explanation(self, mocker):
+        job = Job.objects.create(status='running', name='foo-job', celery_task_id=str(uuid4()), controller_node='foo')
+        job.websocket_emit_status = mocker.MagicMock()
+        job_explanation = 'giggity giggity'
+
+        job.cancel(job_explanation=job_explanation)
+        job.refresh_from_db()
+
+        assert job.job_explanation == job_explanation
+
+    def test_cancel_sends_control_message(self, mocker):
+        celery_task_id = str(uuid4())
+        job = Job.objects.create(status='running', name='foo-job', celery_task_id=celery_task_id, controller_node='foo')
+        job.websocket_emit_status = mocker.MagicMock()
+        control = mocker.MagicMock()
+        get_control = mocker.patch('awx.main.models.unified_jobs.get_control_from_settings', return_value=control)
+
+        job.cancel()
+
+        get_control.assert_called_once_with(default_publish_channel='foo')
+        control.control.assert_called_once_with('cancel', data={'uuid': celery_task_id})
+
+    def test_cancel_refreshes_task_id_before_sending_control(self, mocker):
+        job = Job.objects.create(status='pending', name='foo-job', celery_task_id='', controller_node='bar')
+        job.websocket_emit_status = mocker.MagicMock()
+        celery_task_id = str(uuid4())
+        Job.objects.filter(pk=job.pk).update(status='running', celery_task_id=celery_task_id)
+        control = mocker.MagicMock()
+        get_control = mocker.patch('awx.main.models.unified_jobs.get_control_from_settings', return_value=control)
+        refresh_spy = mocker.spy(job, 'refresh_from_db')
+
+        job.cancel()
+
+        refresh_spy.assert_called_once_with(fields=['celery_task_id', 'controller_node'])
+        get_control.assert_called_once_with(default_publish_channel='bar')
+        control.control.assert_called_once_with('cancel', data={'uuid': celery_task_id})
+
+
 @pytest.mark.django_db
 class TestCreateUnifiedJob:
     """