Catch serializer TypeError Exception (#1872)

* Catch serializer TypeError Exception

* Add test for unserializable job.meta

rq/job.py

@@ -912,7 +912,10 @@ class Job:
         self.allow_dependency_failures = bool(int(allow_failures)) if allow_failures else None
         self.enqueue_at_front = bool(int(obj['enqueue_at_front'])) if 'enqueue_at_front' in obj else None
         self.ttl = int(obj.get('ttl')) if obj.get('ttl') else None
-        self.meta = self.serializer.loads(obj.get('meta')) if obj.get('meta') else {}
+        try:
+            self.meta = self.serializer.loads(obj.get('meta')) if obj.get('meta') else {}
+        except Exception:  # depends on the serializer
+            self.meta = {'unserialized': obj.get('meta', {})}
 
         self.retries_left = int(obj.get('retries_left')) if obj.get('retries_left') else None
         if obj.get('retry_intervals'):

tests/test_worker.py

@@ -225,6 +225,23 @@ class TestWorker(RQTestCase):
         failed_job_registry = FailedJobRegistry(queue=q)
         self.assertTrue(job in failed_job_registry)
 
+    def test_meta_is_unserializable(self):
+        """Unserializable jobs are put on the failed job registry."""
+        q = Queue()
+        self.assertEqual(q.count, 0)
+
+        # NOTE: We have to fake this enqueueing for this test case.
+        # What we're simulating here is a call to a function that is not
+        # importable from the worker process.
+        job = Job.create(func=do_nothing, origin=q.name, meta={'key': 'value'})
+        job.save()
+
+        invalid_meta = '{{{{{{{{INVALID_JSON'
+        self.testconn.hset(job.key, 'meta', invalid_meta)
+        job.refresh()
+        self.assertIsInstance(job.meta, dict)
+        self.assertTrue('unserialized' in job.meta.keys())
+
     @mock.patch('rq.worker.logger.error')
     def test_deserializing_failure_is_handled(self, mock_logger_error):
         """