Improved Test Framework to support promises as returned GraphQL execution

Author: syrusakbary

graphene/test/__init__.py

@@ -1,3 +1,4 @@
+from promise import Promise, is_thenable
 import six
 from graphql.error import format_error as format_graphql_error
 from graphql.error import GraphQLError
@@ -31,9 +32,16 @@ def __init__(self, schema, format_error=None, **execute_options):
         self.schema = schema
         self.execute_options = execute_options
         self.format_error = format_error or default_format_error
-
-    def execute(self, *args, **kwargs):
+    
+    def format_result(self, result):
         return format_execution_result(
-            self.schema.execute(*args, **dict(self.execute_options, **kwargs)),
+            result,
             self.format_error
         )
+
+    def execute(self, *args, **kwargs):
+        executed = self.schema.execute(*args, **dict(self.execute_options, **kwargs))
+        if is_thenable(executed):
+            return Promise.resolve(executed).then(self.format_result)
+        
+        return self.format_result(executed)