fix getattr (#803)

aiobotocore/client.py

@@ -1,3 +1,5 @@
+import asyncio
+
 from botocore.awsrequest import prepare_request_dict
 from botocore.client import logger, PaginatorDocstring, ClientCreator, \
     BaseClient, ClientEndpointBridge
@@ -69,13 +71,48 @@ def _get_client_args(self, service_model, region_name, is_secure,
             verify, credentials, scoped_config, client_config, endpoint_bridge)
 
 
+class _AsyncAttrAdapter:
+    def __init__(self, coro):
+        self._coro = coro
+        self._args = None
+        self._kwargs = None
+
+    def __call__(self, *args, **kwargs):
+        # bind args
+        self._args = args
+        self._kwargs = kwargs
+        return self
+
+    async def _resolve(self):
+        event_response = await self._coro
+        if asyncio.iscoroutinefunction(event_response):
+            result = await event_response(*self._args, **self._kwargs)
+            return result
+
+        if callable(event_response):
+            result = event_response(*self._args, **self._kwargs)
+            if asyncio.iscoroutine(result):
+                result = await result
+            return result
+
+        return event_response
+
+    def __await__(self):
+        return self._resolve().__await__()
+
+
 class AioBaseClient(BaseClient):
-    def __getattr__(self, item):
-        # TODO: this is not supported yet as emit_until_response is an async function
-        raise AttributeError(
-            "'%s' object has no attribute '%s'" % (
-                self.__class__.__name__, item)
+    async def _async_getattr(self, item):
+        event_name = 'getattr.%s.%s' % (
+            self._service_model.service_id.hyphenize(), item
         )
+        handler, event_response = await self.meta.events.emit_until_response(
+            event_name, client=self)
+
+        return event_response
+
+    def __getattr__(self, item):
+        return _AsyncAttrAdapter(self._async_getattr(item))
 
     async def _make_api_call(self, operation_name, api_params):
         operation_model = self._service_model.operation_model(operation_name)

tests/test_mturk.py

@@ -0,0 +1,34 @@
+from botocore.stub import Stubber, ANY
+import pytest
+
+
+_mturk_list_hits_response = {
+    'NumResults': 0,
+    'HITs': [],
+    'ResponseMetadata': {
+        'RequestId': '00000000-4989-4ffc-85cd-aaaaaaaaaaaa',
+        'HTTPStatusCode': 200,
+        'HTTPHeaders': {
+            'x-amzn-requestid': '00000000-4989-4ffc-85cd-aaaaaaaaaaaa',
+            'content-type': 'application/x-amz-json-1.1',
+            'content-length': '26',
+            'date': 'Thu, 04 Jun 2020 00:48:16 GMT'
+        },
+        'RetryAttempts': 0
+    }
+}
+
+
+# Unfortunately moto does not support mturk yet
+@pytest.mark.moto
+@pytest.mark.asyncio
+async def test_mturk_stubber(session):
+    async with session.create_client('mturk', region_name='us-east-1') as client:
+        with Stubber(client) as stubber:
+            stubber.add_response('list_hits_for_qualification_type',
+                                 _mturk_list_hits_response,
+                                 {'QualificationTypeId': ANY})
+
+            response = await client.list_hi_ts_for_qualification_type(
+                QualificationTypeId='string')
+            assert response == _mturk_list_hits_response