Await subscribed execution results (#10)

Author: Cito

README.md

@@ -12,7 +12,7 @@ a query language for APIs created by Facebook.
 [![Python 3 Status](https://pyup.io/repos/github/graphql-python/graphql-core-next/python-3-shield.svg)](https://pyup.io/repos/github/graphql-python/graphql-core-next/)
 
 The current version 1.0.1 of GraphQL-core-next is up-to-date with GraphQL.js version
-14.0.2. All parts of the API are covered by an extensive test suite of currently 1618
+14.0.2. All parts of the API are covered by an extensive test suite of currently 1619
 unit tests.
 
 
@@ -182,7 +182,7 @@ Design goals for the GraphQL-core-next library are:
 * to be very close to the GraphQL.js reference implementation, while still using a
   Pythonic API and code style
 * making use of Python type hints, similar to how GraphQL.js makes use of Flow
-* using of [black](https://github.com/ambv/black) for automatic code formatting 
+* using of [black](https://github.com/ambv/black) for automatic code formatting
 * replicate the complete Mocha-based test suite of GraphQL.js using
   [pytest](https://docs.pytest.org/)
 

graphql/subscription/subscribe.py

@@ -74,7 +74,7 @@ async def map_source_to_response(payload):
         as it is nearly identical to the "ExecuteQuery" algorithm, for which `execute`
         is also used.
         """
-        return execute(
+        result = execute(
             schema,
             document,
             payload,
@@ -83,6 +83,7 @@ async def map_source_to_response(payload):
             operation_name,
             field_resolver,
         )
+        return await result if isawaitable(result) else result
 
     return MapAsyncIterator(result_or_stream, map_source_to_response)
 

tests/subscription/test_subscribe.py

@@ -736,3 +736,31 @@ def resolve_fn(event, _info):
 
         with raises(StopAsyncIteration):
             await anext(subscription)
+
+    @mark.asyncio
+    async def should_work_with_async_resolve_function():
+        async def subscribe_fn(_event, _info):
+            yield {"email": {"subject": "Hello"}}
+
+        async def resolve_fn(event, _info):
+            return event
+
+        async_email_schema = email_schema_with_resolvers(subscribe_fn, resolve_fn)
+
+        subscription = await subscribe(
+            async_email_schema,
+            parse(
+                """
+                subscription {
+                  importantEmail {
+                    email {
+                      subject
+                    }
+                  }
+                }
+                """
+            ),
+        )
+
+        payload = await anext(subscription)
+        assert payload == ({"importantEmail": {"email": {"subject": "Hello"}}}, None)