Add SWF endpoint CountPendingDecisionTasks

moto/swf/models/__init__.py

@@ -191,6 +191,16 @@ class SWFBackend(BaseBackend):
         else:
             return None
 
+    def count_pending_decision_tasks(self, domain_name, task_list):
+        self._check_string(domain_name)
+        self._check_string(task_list)
+        domain = self._get_domain(domain_name)
+        count = 0
+        for _, wfe in domain.workflow_executions.iteritems():
+            if wfe.task_list == task_list:
+                count += wfe.open_counts["openDecisionTasks"]
+        return count
+
 
 swf_backends = {}
 for region in boto.swf.regions():

moto/swf/responses.py

@@ -236,3 +236,9 @@ class SWFResponse(BaseResponse):
             )
         else:
             return json.dumps({"previousStartedEventId": 0, "startedEventId": 0})
+
+    def count_pending_decision_tasks(self):
+        domain_name = self._params["domain"]
+        task_list = self._params["taskList"]["name"]
+        count = self.swf_backend.count_pending_decision_tasks(domain_name, task_list)
+        return json.dumps({"count": count, "truncated": False})