[entities] add a revoke method on ICeleryTask

In tests set the name of the worker to te@st so it's easier to get the revoke
task list from the worker.

entities.py

@@ -161,6 +161,10 @@ class ICeleryTask(EntityAdapter):
     def task_name(self):
         raise NotImplementedError
 
+    def revoke(self, terminate=True, signal='SIGKILL'):
+        return celery.task.control.revoke(
+            [self.task_id], terminate=terminate, signal=signal)
+
     @property
     def logs(self):
         return loghelper.get_task_logs(self.task_id) or b''

test/test_celerytask.py

@@ -23,6 +23,7 @@ import unittest
 
 import six
 import celery.result
+import mock
 
 from cubicweb.devtools import testlib  # noqa
 
@@ -222,6 +223,15 @@ class CeleryTaskTC(BaseCeleryTaskTC):
             self.assertEqual(tsum.parent_task, ())
             self.assertEqual(tsum.reverse_parent_task, ())
 
+    def test_revoke(self):
+        with self.admin_access.cnx() as cnx:
+            task = start_async_task(cnx, celery.signature("success"))
+            cnx.commit()
+            with mock.patch('celery.app.control.Control.revoke') as revoke:
+                task.cw_adapt_to('ICeleryTask').revoke()
+            revoke.assert_called_once_with([task.task_id], signal='SIGKILL',
+                                           terminate=True)
+
 
 if __name__ == '__main__':
     from unittest import main

tox.ini

@@ -7,6 +7,7 @@ deps =
   pytest
   pbr>=1.4
   pifpaf
+  mock
   http://hg.logilab.org/review/cw-celerytask-helpers/archive/default.tar.bz2
 commands =
   pifpaf run redis --port 6380 -- {envpython} -m pytest {posargs:test}