assert that an observable is returned

mgasner · Nov 4, 2017 · 24d49dc · 24d49dc
1 parent 7d59cd7
commit 24d49dc
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Showing 2 changed files with 3 additions and 3 deletions.
diff --git a/examples/flask_gevent/src/graphql b/examples/flask_gevent/src/graphql
diff --git a/graphql_ws/gevent_server.py b/graphql_ws/gevent_server.py
@@ -3,8 +3,7 @@
 from graphql import format_error, graphql
 from graphql.execution import ExecutionResult
 from graphql.execution.executors.sync import SyncExecutor
-from rx import Observer
-from promise import is_thenable, Promise
+from rx import Observer, Observable
 from .server import BaseWebSocketSubscriptionServer, ConnectionContext, ConnectionClosedException
 from .constants import *
 
@@ -86,6 +85,8 @@ def on_start(self, connection_context, op_id, params):
  execution_result = graphql(
  self.schema, **params, allow_subscriptions=True
  )
+ assert isinstance(
+ execution_result, Observable), "A subscription must return an observable"
  execution_result.subscribe(SubscriptionObserver(
  connection_context,
  op_id,