Improve async mode exceptions handling to prevent infinite hanging when exception occurs

docs/main/changelog.rst

@@ -9,7 +9,8 @@ follows `Semantic versioning`_
 
 Development version
 -------------------
-- Fix double printing of exception when initializing resource causes error.
+- Improve async mode exceptions handling to prevent infinite hanging when exception occurs.
+- Fix double printing of exception when resource initialization causes an error.
 
 4.23.1
 ------

src/dependency_injector/providers.pxd

@@ -455,10 +455,14 @@ cdef inline void __async_prepare_args_kwargs_callback(
         object awaitables,
         object future,
 ):
-    awaited = future.result()
-    for value, (key, _) in zip(awaited, awaitables):
-        args[key] = value
-    future_result.set_result(args)
+    try:
+        awaited = future.result()
+    except Exception as exception:
+        future_result.set_exception(exception)
+    else:
+        for value, (key, _) in zip(awaited, awaitables):
+            args[key] = value
+        future_result.set_result(args)
 
 
 @cython.boundscheck(False)
@@ -560,19 +564,28 @@ cdef inline object __call(
 
 
 cdef inline void __async_call_callback(object future_result, object call, object future):
-    args, kwargs = future.result()
-    result = call(*args, **kwargs)
+    try:
+        args, kwargs = future.result()
+    except Exception as exception:
+        future_result.set_exception(exception)
+    else:
+        result = call(*args, **kwargs)
 
-    if __isawaitable(result):
-        result = asyncio.ensure_future(result)
-        result.add_done_callback(functools.partial(__async_result_callback, future_result))
-        return
+        if __isawaitable(result):
+            result = asyncio.ensure_future(result)
+            result.add_done_callback(functools.partial(__async_result_callback, future_result))
+            return
 
-    future_result.set_result(result)
+        future_result.set_result(result)
 
 
 cdef inline object __async_result_callback(object future_result, object future):
-    future_result.set_result(future.result())
+    try:
+        result = future.result()
+    except Exception as exception:
+        future_result.set_exception(exception)
+    else:
+        future_result.set_result(result)
 
 
 cdef inline object __callable_call(Callable self, tuple args, dict kwargs):

tests/unit/providers/test_async_py36.py

@@ -190,6 +190,25 @@ class FactoryTests(AsyncTestCase):
 
         self.assertIsNot(service1.client, service2.client)
 
+    def test_kwargs_error_injection(self):
+        async def init_resource():
+            raise Exception('Something went wrong')
+
+        class Container(containers.DeclarativeContainer):
+            resource_with_error = providers.Resource(init_resource)
+
+            client = providers.Factory(
+                Client,
+                resource1=resource_with_error,
+                resource2=None,
+            )
+
+        container = Container()
+
+        with self.assertRaises(Exception) as context:
+            self._run(container.client())
+        self.assertEqual(str(context.exception), 'Something went wrong')
+
     def test_attributes_injection(self):
         class ContainerWithAttributes(containers.DeclarativeContainer):
             resource1 = providers.Resource(init_resource, providers.Object(RESOURCE1))