Async resources and injections (#352)

* Add support of async injections into wiring

* Add support of async functions and async generators for resources

* Update resource provider typing stub for stutdown

* Add resource base class for async resources

* Fix tests

* Add tests for async injections in wiring @inject

* Refactor provider tests

* Add tests for async resources

* Rework async resources callbacks to .add_done_callback() style (fixes pypy3 issue)

* Add awaits into async resource class test

* Refactor FastAPI tests

* Implement async resources initialization in container

* Move container async resource tests to a separate module for Python 3.6+

* Fix init async resources in container on Python 2

* Add first dirty async injections implementation

* Fix isawaitable error

* Turm asyncio import to conditional for safer Py2 usage

* Refactor kwargs injections

* Implement positional injections, add tests and make refactoring

* Implement attribute injections and add tests

* Add singleton implementation + tests for all singleton types

* Implement injections in thread-local and thread-safe singleton providers

* Update .provided + fix resource concurent initialization issue

* Implement async mode for Dependency provider

* Add async mode for the provider

* Add overload for Factory typing

* Add typing stubs for async resource

* Refactor abstract* providers __call__()

* Add async mode API + tests

* Add typing stubs & tests for async mode API

* Add tests for async mode auto configuration

* Refactor Provider.__call__() to use async mode api

* Refactor Dependency provider to use async mode api

* Add tests for Dependency provider async mode

* Add support of async mode for FactoryAggregate provider + tests

* Refactor Singleton provider to use async mode api

* Refactor ThreadSafeSingleton provider to use async mode api

* Refactor ThreadLocalSingleton provider to use async mode api

* Finish Singleton refactoring to use async mode api

* Refactor Resource provider to use async mode api

* Add Provider.async_() method + tests

* Add typing stubs for async_() method + tests

* Refactor Singleton typing stubs to return singleton from argument methods

* Refactor provider typing stubs

* Improve resource typing stub

* Add tests for async context kwargs injections

* Fix typo in resource provider tests

* Cover shutdown of not initialized resource

* Add test to cover resource initialization with an error

* Fix Singleton and ThreadLocalSingleton to handle initialization errors

* Add FastAPI + Redis example

* Make cosmetic fixes to FastAPI + Redis example

* Add missing development requirements

* Update module docblock in fastapi + redis example

* Add FastAPI + Redis example docs

* Add references to FastAPI + Redis example

* Refactor resource docs

* Add asynchronous resources docs

* Refactor wiring docs

* Add async injections docs for wiring

* Add async injections page and update docs index, readme, and key features pages

* Add providers async injections example

* Add docs on provider async mode enabling

* Reword async provider docs

* Add provider async mode docs

* Add cross links to async docs

* Mute flake8 errors in async provider examples

* Update changelog

* Make cosmetic fix to containers.pyx

README.rst

@@ -70,6 +70,8 @@ Key features of the ``Dependency Injector``:
 - **Wiring**. Injects dependencies into functions and methods. Helps integrating with
   other frameworks: Django, Flask, Aiohttp, Sanic, FastAPI, etc.
   See `Wiring <https://python-dependency-injector.ets-labs.org/wiring.html>`_.
+- **Asynchronous**. Supports asynchronous injections.
+  See `Asynchronous injections <https://python-dependency-injector.ets-labs.org/providers/async.html>`_.
 - **Typing**. Provides typing stubs, ``mypy``-friendly.
   See `Typing and mypy <https://python-dependency-injector.ets-labs.org/providers/typing_mypy.html>`_.
 - **Performance**. Fast. Written in ``Cython``.
@@ -157,6 +159,8 @@ Choose one of the following:
 - `Flask example <https://python-dependency-injector.ets-labs.org/examples/flask.html>`_
 - `Aiohttp example <https://python-dependency-injector.ets-labs.org/examples/aiohttp.html>`_
 - `Sanic example <https://python-dependency-injector.ets-labs.org/examples/sanic.html>`_
+- `FastAPI example <https://python-dependency-injector.ets-labs.org/examples/fastapi.html>`_
+- `FastAPI + Redis example <https://python-dependency-injector.ets-labs.org/examples/fastapi-redis.html>`_
 
 Tutorials
 ---------
@@ -223,4 +227,3 @@ Want to contribute?
 .. |tell| unicode:: U+1F4AC .. tell sign
 .. |fork| unicode:: U+1F500 .. fork sign
 .. |pull| unicode:: U+2B05 U+FE0F .. pull sign
-

docs/examples/fastapi-redis.rst

@@ -0,0 +1,98 @@
+.. _fastapi-redis-example:
+
+FastAPI + Redis example
+=======================
+
+.. meta::
+   :keywords: Python,Dependency Injection,FastAPI,Redis,Example
+   :description: This example demonstrates a usage of the FastAPI, Redis, and Dependency Injector.
+
+This example shows how to use ``Dependency Injector`` with `FastAPI <https://fastapi.tiangolo.com/>`_ and
+`Redis <https://redis.io/>`_.
+
+The source code is available on the `Github <https://github.com/ets-labs/python-dependency-injector/tree/master/examples/miniapps/fastapi-redis>`_.
+
+See also:
+
+- Provider :ref:`async-injections`
+- Resource provider :ref:`resource-async-initializers`
+- Wiring :ref:`async-injections-wiring`
+
+Application structure
+---------------------
+
+Application has next structure:
+
+.. code-block:: bash
+
+   ./
+   ├── fastapiredis/
+   │   ├── __init__.py
+   │   ├── application.py
+   │   ├── containers.py
+   │   ├── redis.py
+   │   ├── services.py
+   │   └── tests.py
+   ├── docker-compose.yml
+   ├── Dockerfile
+   └── requirements.txt
+
+Redis
+-----
+
+Module ``redis`` defines Redis connection pool initialization and shutdown. See ``fastapiredis/redis.py``:
+
+.. literalinclude:: ../../examples/miniapps/fastapi-redis/fastapiredis/redis.py
+   :language: python
+
+Service
+-------
+
+Module ``services`` contains example service. Service has a dependency on Redis connection pool.
+It uses it for getting and setting a key asynchronously. Real life service will do something more meaningful.
+See ``fastapiredis/services.py``:
+
+.. literalinclude:: ../../examples/miniapps/fastapi-redis/fastapiredis/services.py
+   :language: python
+
+Container
+---------
+
+Declarative container wires example service with Redis connection pool. See ``fastapiredis/containers.py``:
+
+.. literalinclude:: ../../examples/miniapps/fastapi-redis/fastapiredis/containers.py
+   :language: python
+
+Application
+-----------
+
+Module ``application`` creates ``FastAPI`` app, setup endpoint, and init container.
+
+Endpoint ``index`` has a dependency on example service. The dependency is injected using :ref:`wiring` feature.
+
+Listing of ``fastapiredis/application.py``:
+
+.. literalinclude:: ../../examples/miniapps/fastapi-redis/fastapiredis/application.py
+   :language: python
+
+Tests
+-----
+
+Tests use :ref:`provider-overriding` feature to replace example service with a mock. See ``fastapiredis/tests.py``:
+
+.. literalinclude:: ../../examples/miniapps/fastapi-redis/fastapiredis/tests.py
+   :language: python
+   :emphasize-lines: 24
+
+Sources
+-------
+
+The source code is available on the `Github <https://github.com/ets-labs/python-dependency-injector/tree/master/examples/miniapps/fastapi-redis>`_.
+
+See also:
+
+- Provider :ref:`async-injections`
+- Resource provider :ref:`resource-async-initializers`
+- Wiring :ref:`async-injections-wiring`
+
+.. disqus::

docs/examples/index.rst

@@ -19,5 +19,6 @@ Explore the examples to see the ``Dependency Injector`` in action.
     aiohttp
     sanic
     fastapi
+    fastapi-redis
 
 .. disqus::

docs/index.rst

@@ -78,6 +78,7 @@ Key features of the ``Dependency Injector``:
 - **Containers**. Provides declarative and dynamic containers. See :ref:`containers`.
 - **Wiring**. Injects dependencies into functions and methods. Helps integrating with
   other frameworks: Django, Flask, Aiohttp, Sanic, FastAPI, etc. See :ref:`wiring`.
+- **Asynchronous**. Supports asynchronous injections. See :ref:`async-injections`.
 - **Typing**. Provides typing stubs, ``mypy``-friendly. See :ref:`provider-typing`.
 - **Performance**. Fast. Written in ``Cython``.
 - **Maturity**. Mature and production-ready. Well-tested, documented and supported.

docs/introduction/di_in_python.rst

@@ -287,6 +287,7 @@ Choose one of the following as a next step:
     - :ref:`aiohttp-example`
     - :ref:`sanic-example`
     - :ref:`fastapi-example`
+    - :ref:`fastapi-redis-example`
 - Pass the tutorials:
     - :ref:`flask-tutorial`
     - :ref:`aiohttp-tutorial`

docs/introduction/key_features.rst

@@ -24,6 +24,7 @@ Key features of the ``Dependency Injector``:
 - **Containers**. Provides declarative and dynamic containers. See :ref:`containers`.
 - **Wiring**. Injects dependencies into functions and methods. Helps integrating with
   other frameworks: Django, Flask, Aiohttp, Sanic, FastAPI, etc. See :ref:`wiring`.
+- **Asynchronous**. Supports asynchronous injections. See :ref:`async-injections`.
 - **Typing**. Provides typing stubs, ``mypy``-friendly. See :ref:`provider-typing`.
 - **Performance**. Fast. Written in ``Cython``.
 - **Maturity**. Mature and production-ready. Well-tested, documented and supported.

docs/main/changelog.rst

@@ -9,6 +9,10 @@ follows `Semantic versioning`_
 
 Development version
 -------------------
+- Add support of async injections for providers.
+- Add support of async injections for wiring.
+- Add support of async initializers for ``Resource`` provider.
+- Add ``FastAPI`` + ``Redis`` example.
 - Add ARM wheel builds.
   See issue `#342 <https://github.com/ets-labs/python-dependency-injector/issues/342>`_ for details.
 - Fix a typo in `ext.flask` deprecation warning.

docs/providers/async.rst

@@ -0,0 +1,108 @@
+.. _async-injections:
+
+Asynchronous injections
+=======================
+
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control,Providers,Async,Injections,Asynchronous,Await,
+              Asyncio
+   :description: Dependency Injector providers support asynchronous injections. This page
+                 demonstrates how make asynchronous dependency injections in Python.
+
+Providers support asynchronous injections.
+
+.. literalinclude:: ../../examples/providers/async.py
+   :language: python
+   :emphasize-lines: 26-29
+   :lines: 3-
+
+If provider has any awaitable injections it switches into async mode. In async mode provider always returns awaitable.
+This causes a cascade effect:
+
+.. code-block:: bash
+
+   provider1()              <── Async mode enabled <──┐
+   │                                                  │
+   ├──> provider2()                                   │
+   │                                                  │
+   ├──> provider3()         <── Async mode enabled <──┤
+   │    │                                             │
+   │    └──> provider4()    <── Async provider ───────┘
+   │
+   └──> provider5()
+        │
+        └──> provider6()
+
+In async mode provider prepares injections asynchronously.
+
+If provider has multiple awaitable dependencies, it will run them concurrently. Provider will wait until all
+dependencies are ready and inject them afterwards.
+
+.. code-block:: bash
+
+   provider1()
+   │
+   ├──> provider2()         <── Async mode enabled
+   │
+   ├──> provider3()         <── Async mode enabled
+   │
+   └──> provider4()         <── Async mode enabled
+
+Here is what provider will do for the previous example:
+
+.. code-block:: python
+
+   injections = await asyncio.gather(
+       provider2(),
+       provider3(),
+       provider4(),
+   )
+   await provider1(*injections)
+
+Overriding behaviour
+--------------------
+
+In async mode provider always returns awaitable. It applies to the overriding too. If provider in async mode is
+overridden by a provider that doesn't return awaitable result, the result will be wrapped into awaitable.
+
+.. literalinclude:: ../../examples/providers/async_overriding.py
+   :language: python
+   :emphasize-lines: 19-24
+   :lines: 3-
+
+Async mode mechanics and API
+----------------------------
+
+By default provider's async mode is undefined.
+
+When provider async mode is undefined, provider will automatically select the mode during the next call.
+If the result is awaitable, provider will enable async mode, if not - disable it.
+
+If provider async mode is enabled, provider always returns awaitable. If the result is not awaitable,
+provider wraps it into awaitable explicitly. You can safely ``await`` provider in async mode.
+
+If provider async mode is disabled, provider behaves the regular way. It doesn't do async injections
+preparation or non-awaitables to awaitables conversion.
+
+Once provider async mode is enabled or disabled, provider will stay in this state. No automatic switching
+will be done.
+
+.. image:: images/async_mode.png
+
+You can also use following methods to change provider's async mode manually:
+
+- ``Provider.enable_async_mode()``
+- ``Provider.disable_async_mode()``
+- ``Provider.reset_async_mode()``
+
+To check the state of provider's async mode use:
+
+- ``Provider.is_async_mode_enabled()``
+- ``Provider.is_async_mode_disabled()``
+- ``Provider.is_async_mode_undefined()``
+
+See also:
+
+- Wiring :ref:`async-injections-wiring`
+- Resource provider :ref:`resource-async-initializers`
+- :ref:`fastapi-redis-example`

docs/providers/index.rst

@@ -51,4 +51,5 @@ Providers module API docs - :py:mod:`dependency_injector.providers`
     overriding
     provided_instance
     custom
+    async
     typing_mypy

docs/providers/resource.rst

@@ -21,7 +21,7 @@ Resource provider
 Resource providers help to initialize and configure logging, event loop, thread or process pool, etc.
 
 Resource provider is similar to ``Singleton``. Resource initialization happens only once.
-You can do injections and use provided instance the same way like you do with any other provider.
+You can make injections and use provided instance the same way like you do with any other provider.
 
 .. code-block:: python
    :emphasize-lines: 12
@@ -40,7 +40,7 @@ You can do injections and use provided instance the same way like you do with an
            executor=thread_pool,
        )
 
-Container has an interface to initialize and shutdown all resources:
+Container has an interface to initialize and shutdown all resources at once:
 
 .. code-block:: python
 
@@ -48,7 +48,7 @@ Container has an interface to initialize and shutdown all resources:
    container.init_resources()
    container.shutdown_resources()
 
-You also can initialize and shutdown resources one-by-one using ``init()`` and
+You can also initialize and shutdown resources one-by-one using ``init()`` and
 ``shutdown()`` methods of the provider:
 
 .. code-block:: python
@@ -57,6 +57,10 @@ You also can initialize and shutdown resources one-by-one using ``init()`` and
    container.thread_pool.init()
    container.thread_pool.shutdown()
 
+When you call ``.shutdown()`` method on a resource provider, it will remove the reference to the initialized resource,
+if any, and switch to uninitialized state. Some of resource initializer types support specifying custom
+resource shutdown.
+
 Resource provider supports 3 types of initializers:
 
 - Function
@@ -97,7 +101,7 @@ you configure global resource:
            fname='logging.ini',
        )
 
-Function initializer does not support shutdown.
+Function initializer does not provide a way to specify custom resource shutdown.
 
 Generator initializer
 ---------------------
@@ -235,4 +239,124 @@ The example above produces next output:
    Shutdown service
    127.0.0.1 - - [29/Oct/2020 22:39:41] "GET / HTTP/1.1" 200 -
 
+.. _resource-async-initializers:
+
+Asynchronous initializers
+-------------------------
+
+When you write an asynchronous application, you might need to initialize resources asynchronously. Resource
+provider supports asynchronous initialization and shutdown.
+
+Asynchronous function initializer:
+
+.. code-block:: python
+
+   async def init_async_resource(argument1=..., argument2=...):
+       return await connect()
+
+
+   class Container(containers.DeclarativeContainer):
+
+       resource = providers.Resource(
+           init_resource,
+           argument1=...,
+           argument2=...,
+       )
+
+Asynchronous generator initializer:
+
+.. code-block:: python
+
+   async def init_async_resource(argument1=..., argument2=...):
+       connection = await connect()
+       yield connection
+       await connection.close()
+
+
+   class Container(containers.DeclarativeContainer):
+
+       resource = providers.Resource(
+           init_async_resource,
+           argument1=...,
+           argument2=...,
+       )
+
+Asynchronous subclass initializer:
+
+.. code-block:: python
+
+   from dependency_injector import resources
+
+
+   class AsyncConnection(resources.AsyncResource):
+
+       async def init(self, argument1=..., argument2=...):
+           yield await connect()
+
+       async def shutdown(self, connection):
+           await connection.close()
+
+
+   class Container(containers.DeclarativeContainer):
+
+       resource = providers.Resource(
+           AsyncConnection,
+           argument1=...,
+           argument2=...,
+       )
+
+When you use resource provider with asynchronous initializer you need to call its ``__call__()``,
+``init()``, and ``shutdown()`` methods asynchronously:
+
+.. code-block:: python
+
+   import asyncio
+
+
+   class Container(containers.DeclarativeContainer):
+
+       connection = providers.Resource(init_async_connection)
+
+
+   async def main():
+       container = Container()
+       connection = await container.connection()
+       connection = await container.connection.init()
+       connection = await container.connection.shutdown()
+
+
+   if __name__ == '__main__':
+       asyncio.run(main())
+
+Container ``init_resources()`` and ``shutdown_resources()`` methods should be used asynchronously if there is
+at least one asynchronous resource provider:
+
+.. code-block:: python
+
+   import asyncio
+
+
+   class Container(containers.DeclarativeContainer):
+
+       connection1 = providers.Resource(init_async_connection)
+
+       connection2 = providers.Resource(init_sync_connection)
+
+
+   async def main():
+       container = Container()
+       await container.init_resources()
+       await container.shutdown_resources()
+
+
+   if __name__ == '__main__':
+       asyncio.run(main())
+
+See also:
+
+- Provider :ref:`async-injections`
+- Wiring :ref:`async-injections-wiring`
+- :ref:`fastapi-redis-example`
+
+
 .. disqus::

docs/wiring.rst

@@ -167,21 +167,105 @@ You can use that in testing to re-create and re-wire a container before each tes
    avoid re-wiring between tests.
 
 .. note::
-   Python has a limitation on patching already imported individual members. To protect from errors
+   Python has a limitation on patching individually imported functions. To protect from errors
-   prefer an import of modules instead of individual members or make sure that imports happen
+   prefer importing modules to importing individual functions or make sure imports happen
    after the wiring:
 
    .. code-block:: python
 
+      # Potential error:
+
+      from .module import fn
+
+      fn()
+
+   Instead use next:
+
+   .. code-block:: python
+
+      # Always works:
+
       from . import module
 
       module.fn()
 
-      # instead of
+.. _async-injections-wiring:
 
-      from .module import fn
+Asynchronous injections
+-----------------------
 
-      fn()
+Wiring feature supports asynchronous injections:
+
+.. code-block:: python
+
+   class Container(containers.DeclarativeContainer):
+
+       db = providers.Resource(init_async_db_client)
+
+       cache = providers.Resource(init_async_cache_client)
+
+
+   @inject
+   async def main(
+       db: Database = Provide[Container.db],
+       cache: Cache = Provide[Container.cache],
+   ):
+       ...
+
+When you call asynchronous function wiring prepares injections asynchronously.
+Here is what it does for previous example:
+
+.. code-block:: python
+
+    db, cache = await asyncio.gather(
+        container.db(),
+        container.cache(),
+    )
+
+    await main(db=db, cache=cache)
+
+You can also use ``Closing`` marker with the asynchronous ``Resource`` providers:
+
+.. code-block:: python
+
+   @inject
+   async def main(
+       db: Database = Closing[Provide[Container.db]],
+       cache: Cache = Closing[Provide[Container.cache]],
+   ):
+       ...
+
+Wiring does closing asynchronously:
+
+.. code-block:: python
+
+    db, cache = await asyncio.gather(
+        container.db(),
+        container.cache(),
+    )
+
+    await main(db=db, cache=cache)
+
+    await asyncio.gather(
+        container.db.shutdown(),
+        container.cache.shutdown(),
+    )
+
+See :ref:`Resources, wiring and per-function execution scope <resource-provider-wiring-closing>` for
+details on ``Closing`` marker.
+
+.. note::
+
+   Wiring does not not convert asynchronous injections to synchronous.
+
+   It handles asynchronous injections only for ``async def`` functions. Asynchronous injections into
+   synchronous ``def`` function still work, but you need to take care of awaitables by your own.
+
+See also:
+
+- Provider :ref:`async-injections`
+- Resource provider :ref:`resource-async-initializers`
+- :ref:`fastapi-redis-example`
 
 Integration with other frameworks
 ---------------------------------
@@ -211,5 +295,6 @@ Take a look at other application examples:
 - :ref:`aiohttp-example`
 - :ref:`sanic-example`
 - :ref:`fastapi-example`
+- :ref:`fastapi-redis-example`
 
 .. disqus::

examples/miniapps/fastapi-redis/Dockerfile

@@ -0,0 +1,10 @@
+FROM python:3.8-buster
+
+ENV PYTHONUNBUFFERED=1
+
+WORKDIR /code
+COPY . /code/
+
+RUN pip install -r requirements.txt
+
+CMD ["uvicorn", "fastapiredis.application:app", "--host", "0.0.0.0"]

examples/miniapps/fastapi-redis/README.rst

@@ -0,0 +1,89 @@
+FastAPI + Redis + Dependency Injector Example
+=============================================
+
+This is a `FastAPI <https://docs.python.org/3/library/asyncio.html>`_
++ `Redis <https://redis.io/>`_
++ `Dependency Injector <https://python-dependency-injector.ets-labs.org/>`_ example application.
+
+Run
+---
+
+Build the Docker image:
+
+.. code-block:: bash
+
+   docker-compose build
+
+Run the docker-compose environment:
+
+.. code-block:: bash
+
+    docker-compose up
+
+The output should be something like:
+
+.. code-block::
+
+   redis_1    | 1:C 04 Jan 2021 02:42:14.115 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
+   redis_1    | 1:C 04 Jan 2021 02:42:14.115 # Redis version=6.0.9, bits=64, commit=00000000, modified=0, pid=1, just started
+   redis_1    | 1:C 04 Jan 2021 02:42:14.115 # Configuration loaded
+   redis_1    | 1:M 04 Jan 2021 02:42:14.116 * Running mode=standalone, port=6379.
+   redis_1    | 1:M 04 Jan 2021 02:42:14.116 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
+   redis_1    | 1:M 04 Jan 2021 02:42:14.116 # Server initialized
+   redis_1    | 1:M 04 Jan 2021 02:42:14.117 * Loading RDB produced by version 6.0.9
+   redis_1    | 1:M 04 Jan 2021 02:42:14.117 * RDB age 1 seconds
+   redis_1    | 1:M 04 Jan 2021 02:42:14.117 * RDB memory usage when created 0.77 Mb
+   redis_1    | 1:M 04 Jan 2021 02:42:14.117 * DB loaded from disk: 0.000 seconds
+   redis_1    | 1:M 04 Jan 2021 02:42:14.117 * Ready to accept connections
+   redis_1    | 1:signal-handler (1609728137) Received SIGTERM scheduling shutdown...
+   redis_1    | 1:M 04 Jan 2021 02:42:17.984 # User requested shutdown...
+   redis_1    | 1:M 04 Jan 2021 02:42:17.984 # Redis is now ready to exit, bye bye...
+   redis_1    | 1:C 04 Jan 2021 02:42:22.035 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
+   redis_1    | 1:C 04 Jan 2021 02:42:22.035 # Redis version=6.0.9, bits=64, commit=00000000, modified=0, pid=1, just started
+   redis_1    | 1:C 04 Jan 2021 02:42:22.035 # Configuration loaded
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 * Running mode=standalone, port=6379.
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 # Server initialized
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 * Loading RDB produced by version 6.0.9
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 * RDB age 9 seconds
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 * RDB memory usage when created 0.77 Mb
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 * DB loaded from disk: 0.000 seconds
+   redis_1    | 1:M 04 Jan 2021 02:42:22.037 * Ready to accept connections
+   example_1  | INFO:     Started server process [1]
+   example_1  | INFO:     Waiting for application startup.
+   example_1  | INFO:     Application startup complete.
+   example_1  | INFO:     Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
+
+Test
+----
+
+This application comes with the unit tests.
+
+To run the tests do:
+
+.. code-block:: bash
+
+   docker-compose run --rm example py.test fastapiredis/tests.py --cov=fastapiredis
+
+The output should be something like:
+
+.. code-block::
+
+   platform linux -- Python 3.8.6, pytest-6.2.1, py-1.10.0, pluggy-0.13.1
+   rootdir: /code
+   plugins: cov-2.10.1, asyncio-0.14.0
+   collected 1 item
+
+   fastapiredis/tests.py .                                         [100%]
+
+   ----------- coverage: platform linux, python 3.8.6-final-0 -----------
+   Name                          Stmts   Miss  Cover
+   -------------------------------------------------
+   fastapiredis/__init__.py          0      0   100%
+   fastapiredis/application.py      15      0   100%
+   fastapiredis/containers.py        6      0   100%
+   fastapiredis/redis.py             7      4    43%
+   fastapiredis/services.py          7      3    57%
+   fastapiredis/tests.py            18      0   100%
+   -------------------------------------------------
+   TOTAL                            53      7    87%

examples/miniapps/fastapi-redis/docker-compose.yml

@@ -0,0 +1,21 @@
+version: "3.7"
+
+services:
+
+  example:
+    build: .
+    environment:
+      REDIS_HOST: "redis"
+      REDIS_PASSWORD: "password"
+    ports:
+      - "8000:8000"
+    volumes:
+      - "./:/code"
+    depends_on:
+      - "redis"
+
+  redis:
+    image: redis
+    command: ["redis-server",  "--requirepass", "password"]
+    ports:
+      - "6379:6379"

examples/miniapps/fastapi-redis/fastapiredis/__init__.py

@@ -0,0 +1 @@
+"""Top-level package."""

examples/miniapps/fastapi-redis/fastapiredis/application.py

@@ -0,0 +1,25 @@
+"""Application module."""
+
+import sys
+
+from fastapi import FastAPI, Depends
+from dependency_injector.wiring import inject, Provide
+
+from .containers import Container
+from .services import Service
+
+
+app = FastAPI()
+
+
+@app.api_route('/')
+@inject
+async def index(service: Service = Depends(Provide[Container.service])):
+    value = await service.process()
+    return {'result': value}
+
+
+container = Container()
+container.config.redis_host.from_env('REDIS_HOST', 'localhost')
+container.config.redis_password.from_env('REDIS_PASSWORD', 'password')
+container.wire(modules=[sys.modules[__name__]])

examples/miniapps/fastapi-redis/fastapiredis/containers.py

@@ -0,0 +1,21 @@
+"""Containers module."""
+
+from dependency_injector import containers, providers
+
+from . import redis, services
+
+
+class Container(containers.DeclarativeContainer):
+
+    config = providers.Configuration()
+
+    redis_pool = providers.Resource(
+        redis.init_redis_pool,
+        host=config.redis_host,
+        password=config.redis_password,
+    )
+
+    service = providers.Factory(
+        services.Service,
+        redis=redis_pool,
+    )

examples/miniapps/fastapi-redis/fastapiredis/redis.py

@@ -0,0 +1,12 @@
+"""Redis client module."""
+
+from typing import AsyncIterator
+
+from aioredis import create_redis_pool, Redis
+
+
+async def init_redis_pool(host: str, password: str) -> AsyncIterator[Redis]:
+    pool = await create_redis_pool(f'redis://{host}', password=password)
+    yield pool
+    pool.close()
+    await pool.wait_closed()

examples/miniapps/fastapi-redis/fastapiredis/services.py

@@ -0,0 +1,12 @@
+"""Services module."""
+
+from aioredis import Redis
+
+
+class Service:
+    def __init__(self, redis: Redis) -> None:
+        self._redis = redis
+
+    async def process(self) -> str:
+        await self._redis.set('my-key', 'value')
+        return await self._redis.get('my-key', encoding='utf-8')

examples/miniapps/fastapi-redis/fastapiredis/tests.py

@@ -0,0 +1,28 @@
+"""Tests module."""
+
+from unittest import mock
+
+import pytest
+from httpx import AsyncClient
+
+from .application import app, container
+from .services import Service
+
+
+@pytest.fixture
+def client(event_loop):
+    client = AsyncClient(app=app, base_url='http://test')
+    yield client
+    event_loop.run_until_complete(client.aclose())
+
+
+@pytest.mark.asyncio
+async def test_index(client):
+    service_mock = mock.AsyncMock(spec=Service)
+    service_mock.process.return_value = 'Foo'
+
+    with container.service.override(service_mock):
+        response = await client.get('/')
+
+    assert response.status_code == 200
+    assert response.json() == {'result': 'Foo'}

examples/miniapps/fastapi-redis/requirements.txt

@@ -0,0 +1,10 @@
+dependency-injector
+fastapi
+uvicorn
+aioredis
+
+# For testing:
+pytest
+pytest-asyncio
+pytest-cov
+httpx

examples/providers/async.py

@@ -0,0 +1,37 @@
+"""Asynchronous injections example."""
+
+import asyncio
+
+from dependency_injector import containers, providers
+
+
+async def init_async_resource():
+    await asyncio.sleep(0.1)
+    yield 'Initialized'
+
+
+class Service:
+    def __init__(self, resource):
+        self.resource = resource
+
+
+class Container(containers.DeclarativeContainer):
+
+    resource = providers.Resource(init_async_resource)
+
+    service = providers.Factory(
+        Service,
+        resource=resource,
+    )
+
+
+async def main(container: Container):
+    resource = await container.resource()
+    service = await container.service()
+    ...
+
+
+if __name__ == '__main__':
+    container = Container()
+
+    asyncio.run(main(container))

examples/providers/async_overriding.py

@@ -0,0 +1,32 @@
+"""Provider overriding in async mode example."""
+
+import asyncio
+
+from dependency_injector import containers, providers
+
+
+async def init_async_resource():
+    return ...
+
+
+def init_resource_mock():
+    return ...
+
+
+class Container(containers.DeclarativeContainer):
+
+    resource = providers.Resource(init_async_resource)
+
+
+async def main(container: Container):
+    resource1 = await container.resource()
+
+    container.resource.override(providers.Callable(init_resource_mock))
+    resource2 = await container.resource()
+    ...
+
+
+if __name__ == '__main__':
+    container = Container()
+
+    asyncio.run(main(container))

requirements-dev.txt

@@ -7,5 +7,8 @@ pydocstyle
 sphinx_autobuild
 pip
 mypy
+pyyaml
+httpx
+fastapi
 
 -r requirements-ext.txt

setup.cfg

@@ -4,6 +4,8 @@ max_complexity = 10
 exclude = types.py
 per-file-ignores =
     examples/demo/*: F841
+    examples/providers/async.py: F841
+    examples/providers/async_overriding.py: F841
     examples/wiring/*: F841
 
 [pydocstyle]

src/dependency_injector/containers.pxd

@@ -11,3 +11,6 @@ cpdef bint is_container(object instance)
 
 
 cpdef object _check_provider_type(object container, object provider)
+
+
+cpdef bint _isawaitable(object instance)

src/dependency_injector/containers.pyi

@@ -1,5 +1,17 @@
 from types import ModuleType
-from typing import Type, Dict, Tuple, Optional, Any, Union, ClassVar, Callable as _Callable, Iterable, TypeVar
+from typing import (
+    Type,
+    Dict,
+    Tuple,
+    Optional,
+    Any,
+    Union,
+    ClassVar,
+    Callable as _Callable,
+    Iterable,
+    TypeVar,
+    Awaitable,
+)
 
 from .providers import Provider
 
@@ -25,8 +37,8 @@ class Container:
     def resolve_provider_name(self, provider_to_resolve: Provider) -> Optional[str]: ...
     def wire(self, modules: Optional[Iterable[ModuleType]] = None, packages: Optional[Iterable[ModuleType]] = None) -> None: ...
     def unwire(self) -> None: ...
-    def init_resources(self) -> None: ...
+    def init_resources(self) -> Optional[Awaitable]: ...
-    def shutdown_resources(self) -> None: ...
+    def shutdown_resources(self) -> Optional[Awaitable]: ...
 
 
 class DynamicContainer(Container): ...

src/dependency_injector/containers.pyx

@@ -1,7 +1,13 @@
 """Containers module."""
 
+import inspect
 import sys
 
+try:
+    import asyncio
+except ImportError:
+    asyncio = None
+
 import six
 
 from .errors import Error
@@ -216,17 +222,33 @@ class DynamicContainer(object):
 
     def init_resources(self):
         """Initialize all container resources."""
+        futures = []
         for provider in self.providers.values():
             if not isinstance(provider, Resource):
                 continue
-            provider.init()
+
+            resource = provider.init()
+
+            if _isawaitable(resource):
+                futures.append(resource)
+
+        if futures:
+            return asyncio.gather(*futures)
 
     def shutdown_resources(self):
         """Shutdown all container resources."""
+        futures = []
         for provider in self.providers.values():
             if not isinstance(provider, Resource):
                 continue
-            provider.shutdown()
+
+            shutdown = provider.shutdown()
+
+            if _isawaitable(shutdown):
+                futures.append(shutdown)
+
+        if futures:
+            return asyncio.gather(*futures)
 
 
 class DeclarativeContainerMetaClass(type):
@@ -494,3 +516,10 @@ cpdef object _check_provider_type(object container, object provider):
     if not isinstance(provider, container.provider_type):
         raise Error('{0} can contain only {1} '
                     'instances'.format(container, container.provider_type))
+
+
+cpdef bint _isawaitable(object instance):
+    try:
+        return <bint> inspect.isawaitable(instance)
+    except AttributeError:
+        return <bint> False

src/dependency_injector/providers.pxd

@@ -1,5 +1,12 @@
 """Providers module."""
 
+try:
+    import asyncio
+except ImportError:
+    asyncio = None
+
+import inspect
+
 cimport cython
 
 
@@ -7,6 +14,7 @@ cimport cython
 cdef class Provider(object):
     cdef tuple __overridden
     cdef Provider __last_overriding
+    cdef int __async_mode
 
     cpdef object _provide(self, tuple args, dict kwargs)
     cpdef void _copy_overridings(self, Provider copied, dict memo)
@@ -134,10 +142,10 @@ cdef class FactoryAggregate(Provider):
 # Singleton providers
 cdef class BaseSingleton(Provider):
     cdef Factory __instantiator
+    cdef object __storage
 
 
 cdef class Singleton(BaseSingleton):
-    cdef object __storage
 
     cpdef object _provide(self, tuple args, dict kwargs)
 
@@ -147,7 +155,6 @@ cdef class DelegatedSingleton(Singleton):
 
 
 cdef class ThreadSafeSingleton(BaseSingleton):
-    cdef object __storage
     cdef object __storage_lock
 
     cpdef object _provide(self, tuple args, dict kwargs)
@@ -158,7 +165,6 @@ cdef class DelegatedThreadSafeSingleton(ThreadSafeSingleton):
 
 
 cdef class ThreadLocalSingleton(BaseSingleton):
-    cdef object __storage
 
     cpdef object _provide(self, tuple args, dict kwargs)
 
@@ -331,30 +337,38 @@ cdef inline tuple __separate_prefixed_kwargs(dict kwargs):
 
 @cython.boundscheck(False)
 @cython.wraparound(False)
-cdef inline tuple __provide_positional_args(
+cdef inline object __provide_positional_args(
         tuple args,
         tuple inj_args,
         int inj_args_len,
 ):
     cdef int index
-    cdef list positional_args
+    cdef list positional_args = []
+    cdef list awaitables = []
     cdef PositionalInjection injection
 
     if inj_args_len == 0:
         return args
 
-    positional_args = list()
     for index in range(inj_args_len):
         injection = <PositionalInjection>inj_args[index]
-        positional_args.append(__get_value(injection))
+        value = __get_value(injection)
+        positional_args.append(value)
+
+        if __isawaitable(value):
+            awaitables.append((index, value))
+
     positional_args.extend(args)
 
-    return tuple(positional_args)
+    if awaitables:
+        return __awaitable_args_kwargs_future(positional_args, awaitables)
+
+    return positional_args
 
 
 @cython.boundscheck(False)
 @cython.wraparound(False)
-cdef inline dict __provide_keyword_args(
+cdef inline object __provide_keyword_args(
         dict kwargs,
         tuple inj_kwargs,
         int inj_kwargs_len,
@@ -362,14 +376,18 @@ cdef inline dict __provide_keyword_args(
     cdef int index
     cdef object name
     cdef object value
-    cdef dict prefixed
+    cdef dict prefixed = {}
+    cdef list awaitables = []
     cdef NamedInjection kw_injection
 
     if len(kwargs) == 0:
         for index in range(inj_kwargs_len):
             kw_injection = <NamedInjection>inj_kwargs[index]
             name = __get_name(kw_injection)
-            kwargs[name] = __get_value(kw_injection)
+            value = __get_value(kw_injection)
+            kwargs[name] = value
+            if __isawaitable(value):
+                awaitables.append((name, value))
     else:
         kwargs, prefixed = __separate_prefixed_kwargs(kwargs)
 
@@ -387,23 +405,77 @@ cdef inline dict __provide_keyword_args(
                 value = __get_value(kw_injection)
 
             kwargs[name] = value
+            if __isawaitable(value):
+                awaitables.append((name, value))
+
+    if awaitables:
+        return __awaitable_args_kwargs_future(kwargs, awaitables)
 
     return kwargs
 
 
+cdef inline object __awaitable_args_kwargs_future(object args, list awaitables):
+    future_result = asyncio.Future()
+
+    args_future = asyncio.Future()
+    args_future.set_result((future_result, args, awaitables))
+
+    args_ready = asyncio.gather(args_future, *[value for _, value in awaitables])
+    args_ready.add_done_callback(__async_prepare_args_kwargs_callback)
+    asyncio.ensure_future(args_ready)
+
+    return future_result
+
+
+cdef inline void __async_prepare_args_kwargs_callback(object future):
+    (future_result, args, awaitables), *awaited = future.result()
+    for value, (key, _) in zip(awaited, awaitables):
+        args[key] = value
+    future_result.set_result(args)
+
+
 @cython.boundscheck(False)
 @cython.wraparound(False)
-cdef inline object __inject_attributes(
+cdef inline object __provide_attributes(tuple attributes, int attributes_len):
-        object instance,
-        tuple attributes,
-        int attributes_len,
-):
     cdef NamedInjection attr_injection
+    cdef dict attribute_injections = {}
+    cdef list awaitables = []
+
     for index in range(attributes_len):
         attr_injection = <NamedInjection>attributes[index]
-        setattr(instance,
+        name = __get_name(attr_injection)
-                __get_name(attr_injection),
+        value = __get_value(attr_injection)
-                __get_value(attr_injection))
+        attribute_injections[name] = value
+        if __isawaitable(value):
+            awaitables.append((name, value))
+
+    if awaitables:
+        return __awaitable_args_kwargs_future(attribute_injections, awaitables)
+
+    return attribute_injections
+
+
+cdef inline object __async_inject_attributes(future_instance, future_attributes):
+    future_result = asyncio.Future()
+
+    future = asyncio.Future()
+    future.set_result(future_result)
+
+    attributes_ready = asyncio.gather(future, future_instance, future_attributes)
+    attributes_ready.add_done_callback(__async_inject_attributes_callback)
+    asyncio.ensure_future(attributes_ready)
+
+    return future_result
+
+cdef inline void __async_inject_attributes_callback(future):
+    future_result, instance, attributes = future.result()
+    __inject_attributes(instance, attributes)
+    future_result.set_result(instance)
+
+
+cdef inline void __inject_attributes(object instance, dict attributes):
+    for name, value in attributes.items():
+        setattr(instance, name, value)
 
 
 cdef inline object __call(
@@ -411,25 +483,53 @@ cdef inline object __call(
         tuple context_args,
         tuple injection_args,
         int injection_args_len,
-        dict kwargs,
+        dict context_kwargs,
         tuple injection_kwargs,
         int injection_kwargs_len,
 ):
-    cdef tuple positional_args
+    args = __provide_positional_args(
-    cdef dict keyword_args
-
-    positional_args = __provide_positional_args(
         context_args,
         injection_args,
         injection_args_len,
     )
-    keyword_args = __provide_keyword_args(
+    kwargs = __provide_keyword_args(
-        kwargs,
+        context_kwargs,
         injection_kwargs,
         injection_kwargs_len,
     )
 
-    return call(*positional_args, **keyword_args)
+    args_awaitable = __isawaitable(args)
+    kwargs_awaitable = __isawaitable(kwargs)
+
+    if args_awaitable or kwargs_awaitable:
+        if not args_awaitable:
+            future = asyncio.Future()
+            future.set_result(args)
+            args = future
+
+        if not kwargs_awaitable:
+            future = asyncio.Future()
+            future.set_result(kwargs)
+            kwargs = future
+
+        future_result = asyncio.Future()
+
+        future = asyncio.Future()
+        future.set_result((future_result, call))
+
+        args_kwargs_ready = asyncio.gather(future, args, kwargs)
+        args_kwargs_ready.add_done_callback(__async_call_callback)
+        asyncio.ensure_future(args_kwargs_ready)
+
+        return future_result
+
+    return call(*args, **kwargs)
+
+
+cdef inline void __async_call_callback(object future):
+    (future_result, call), args, kwargs = future.result()
+    result = call(*args, **kwargs)
+    future_result.set_result(result)
 
 
 cdef inline object __callable_call(Callable self, tuple args, dict kwargs):
@@ -450,8 +550,40 @@ cdef inline object __factory_call(Factory self, tuple args, dict kwargs):
     instance = __callable_call(self.__instantiator, args, kwargs)
 
     if self.__attributes_len > 0:
-        __inject_attributes(instance,
+        attributes = __provide_attributes(self.__attributes, self.__attributes_len)
-                            self.__attributes,
+
-                            self.__attributes_len)
+        instance_awaitable = __isawaitable(instance)
+        attributes_awaitable = __isawaitable(attributes)
+
+        if instance_awaitable or attributes_awaitable:
+            if not instance_awaitable:
+                future = asyncio.Future()
+                future.set_result(instance)
+                instance = future
+
+            if not attributes_awaitable:
+                future = asyncio.Future()
+                future.set_result(attributes)
+                attributes = future
+
+            return __async_inject_attributes(instance, attributes)
+
+        __inject_attributes(instance, attributes)
 
     return instance
+
+
+cdef bint __has_isawaitable = False
+
+
+cdef inline bint __isawaitable(object instance):
+    global __has_isawaitable
+
+    if __has_isawaitable is True:
+        return inspect.isawaitable(instance)
+
+    if hasattr(inspect, 'isawaitable'):
+        __has_isawaitable = True
+        return inspect.isawaitable(instance)
+
+    return False

src/dependency_injector/providers.pyi

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 from pathlib import Path
 from typing import (
+    Awaitable,
     TypeVar,
     Generic,
     Type,
@@ -14,6 +15,7 @@ from typing import (
     Union,
     Coroutine as _Coroutine,
     Iterator as _Iterator,
+    AsyncIterator as _AsyncIterator,
     Generator as _Generator,
     overload,
 )
@@ -33,7 +35,13 @@ class OverridingContext:
 
 class Provider(Generic[T]):
     def __init__(self) -> None: ...
+
+    @overload
     def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
+    @overload
+    def __call__(self, *args: Injection, **kwargs: Injection) -> Awaitable[T]: ...
+    def async_(self, *args: Injection, **kwargs: Injection) -> Awaitable[T]: ...
+
     def __deepcopy__(self, memo: Optional[_Dict[Any, Any]]) -> Provider: ...
     def __str__(self) -> str: ...
     def __repr__(self) -> str: ...
@@ -49,30 +57,33 @@ class Provider(Generic[T]):
     def provider(self) -> Provider: ...
     @property
     def provided(self) -> ProvidedInstance: ...
+    def enable_async_mode(self) -> None: ...
+    def disable_async_mode(self) -> None: ...
+    def reset_async_mode(self) -> None: ...
+    def is_async_mode_enabled(self) -> bool: ...
+    def is_async_mode_disabled(self) -> bool: ...
+    def is_async_mode_undefined(self) -> bool: ...
     def _copy_overridings(self, copied: Provider, memo: Optional[_Dict[Any, Any]]) -> None: ...
 
 
-class Object(Provider, Generic[T]):
+class Object(Provider[T]):
     def __init__(self, provides: T) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
 
 
-class Delegate(Provider):
+class Delegate(Provider[Provider]):
     def __init__(self, provides: Provider) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> Provider: ...
     @property
     def provides(self) -> Provider: ...
 
 
-class Dependency(Provider, Generic[T]):
+class Dependency(Provider[T]):
     def __init__(self, instance_of: Type[T] = object) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
     @property
     def instance_of(self) -> Type[T]: ...
     def provided_by(self, provider: Provider) -> OverridingContext: ...
 
 
-class ExternalDependency(Dependency): ...
+class ExternalDependency(Dependency[T]): ...
 
 
 class DependenciesContainer(Object):
@@ -82,9 +93,8 @@ class DependenciesContainer(Object):
     def providers(self) -> _Dict[str, Provider]: ...
 
 
-class Callable(Provider, Generic[T]):
+class Callable(Provider[T]):
     def __init__(self, provides: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
     @property
     def provides(self) -> T: ...
     @property
@@ -93,16 +103,16 @@ class Callable(Provider, Generic[T]):
     def set_args(self, *args: Injection) -> Callable[T]: ...
     def clear_args(self) -> Callable[T]: ...
     @property
-    def kwargs(self) -> _Dict[str, Injection]: ...
+    def kwargs(self) -> _Dict[Any, Injection]: ...
     def add_kwargs(self, **kwargs: Injection) -> Callable[T]: ...
     def set_kwargs(self, **kwargs: Injection) -> Callable[T]: ...
     def clear_kwargs(self) -> Callable[T]: ...
 
 
-class DelegatedCallable(Callable): ...
+class DelegatedCallable(Callable[T]): ...
 
 
-class AbstractCallable(Callable):
+class AbstractCallable(Callable[T]):
     def override(self, provider: Callable) -> OverridingContext: ...
 
 
@@ -110,13 +120,13 @@ class CallableDelegate(Delegate):
     def __init__(self, callable: Callable) -> None: ...
 
 
-class Coroutine(Callable): ...
+class Coroutine(Callable[T]): ...
 
 
-class DelegatedCoroutine(Coroutine): ...
+class DelegatedCoroutine(Coroutine[T]): ...
 
 
-class AbstractCoroutine(Coroutine):
+class AbstractCoroutine(Coroutine[T]):
     def override(self, provider: Coroutine) -> OverridingContext: ...
 
 
@@ -124,10 +134,9 @@ class CoroutineDelegate(Delegate):
     def __init__(self, coroutine: Coroutine) -> None: ...
 
 
-class ConfigurationOption(Provider):
+class ConfigurationOption(Provider[Any]):
     UNDEFINED: object
     def __init__(self, name: Tuple[str], root: Configuration) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> Any: ...
     def __getattr__(self, item: str) -> ConfigurationOption: ...
     def __getitem__(self, item: Union[str, Provider]) -> ConfigurationOption: ...
     @property
@@ -149,7 +158,7 @@ class TypedConfigurationOption(Callable[T]):
     def option(self) -> ConfigurationOption: ...
 
 
-class Configuration(Object):
+class Configuration(Object[Any]):
     DEFAULT_NAME: str = 'config'
     def __init__(self, name: str = DEFAULT_NAME, default: Optional[Any] = None) -> None: ...
     def __getattr__(self, item: str) -> ConfigurationOption: ...
@@ -165,10 +174,9 @@ class Configuration(Object):
     def from_env(self, name: str, default: Optional[Any] = None) -> None: ...
 
 
-class Factory(Provider, Generic[T]):
+class Factory(Provider[T]):
     provided_type: Optional[Type]
     def __init__(self, provides: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
     @property
     def cls(self) -> T: ...
     @property
@@ -179,21 +187,21 @@ class Factory(Provider, Generic[T]):
     def set_args(self, *args: Injection) -> Factory[T]: ...
     def clear_args(self) -> Factory[T]: ...
     @property
-    def kwargs(self) -> _Dict[str, Injection]: ...
+    def kwargs(self) -> _Dict[Any, Injection]: ...
     def add_kwargs(self, **kwargs: Injection) -> Factory[T]: ...
     def set_kwargs(self, **kwargs: Injection) -> Factory[T]: ...
     def clear_kwargs(self) -> Factory[T]: ...
     @property
-    def attributes(self) -> _Dict[str, Injection]: ...
+    def attributes(self) -> _Dict[Any, Injection]: ...
     def add_attributes(self, **kwargs: Injection) -> Factory[T]: ...
     def set_attributes(self, **kwargs: Injection) -> Factory[T]: ...
     def clear_attributes(self) -> Factory[T]: ...
 
 
-class DelegatedFactory(Factory): ...
+class DelegatedFactory(Factory[T]): ...
 
 
-class AbstractFactory(Factory):
+class AbstractFactory(Factory[T]):
     def override(self, provider: Factory) -> OverridingContext: ...
 
 
@@ -203,55 +211,60 @@ class FactoryDelegate(Delegate):
 
 class FactoryAggregate(Provider):
     def __init__(self, **factories: Factory): ...
-    def __call__(self, factory_name: str, *args: Injection, **kwargs: Injection) -> Any: ...
     def __getattr__(self, factory_name: str) -> Factory: ...
+
+    @overload
+    def __call__(self, factory_name: str, *args: Injection, **kwargs: Injection) -> Any: ...
+    @overload
+    def __call__(self, factory_name: str, *args: Injection, **kwargs: Injection) -> Awaitable[Any]: ...
+    def async_(self, factory_name: str, *args: Injection, **kwargs: Injection) -> Awaitable[Any]: ...
+
     @property
     def factories(self) -> _Dict[str, Factory]: ...
 
 
-class BaseSingleton(Provider, Generic[T]):
+class BaseSingleton(Provider[T]):
     provided_type = Optional[Type]
     def __init__(self, provides: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
     @property
     def cls(self) -> T: ...
     @property
     def args(self) -> Tuple[Injection]: ...
-    def add_args(self, *args: Injection) -> Factory[T]: ...
+    def add_args(self, *args: Injection) -> BaseSingleton[T]: ...
-    def set_args(self, *args: Injection) -> Factory[T]: ...
+    def set_args(self, *args: Injection) -> BaseSingleton[T]: ...
-    def clear_args(self) -> Factory[T]: ...
+    def clear_args(self) -> BaseSingleton[T]: ...
     @property
-    def kwargs(self) -> _Dict[str, Injection]: ...
+    def kwargs(self) -> _Dict[Any, Injection]: ...
-    def add_kwargs(self, **kwargs: Injection) -> Factory[T]: ...
+    def add_kwargs(self, **kwargs: Injection) -> BaseSingleton[T]: ...
-    def set_kwargs(self, **kwargs: Injection) -> Factory[T]: ...
+    def set_kwargs(self, **kwargs: Injection) -> BaseSingleton[T]: ...
-    def clear_kwargs(self) -> Factory[T]: ...
+    def clear_kwargs(self) -> BaseSingleton[T]: ...
     @property
-    def attributes(self) -> _Dict[str, Injection]: ...
+    def attributes(self) -> _Dict[Any, Injection]: ...
-    def add_attributes(self, **kwargs: Injection) -> Factory[T]: ...
+    def add_attributes(self, **kwargs: Injection) -> BaseSingleton[T]: ...
-    def set_attributes(self, **kwargs: Injection) -> Factory[T]: ...
+    def set_attributes(self, **kwargs: Injection) -> BaseSingleton[T]: ...
-    def clear_attributes(self) -> Factory[T]: ...
+    def clear_attributes(self) -> BaseSingleton[T]: ...
     def reset(self) -> None: ...
 
 
-class Singleton(BaseSingleton): ...
+class Singleton(BaseSingleton[T]): ...
 
 
-class DelegatedSingleton(Singleton): ...
+class DelegatedSingleton(Singleton[T]): ...
 
 
-class ThreadSafeSingleton(Singleton): ...
+class ThreadSafeSingleton(Singleton[T]): ...
 
 
-class DelegatedThreadSafeSingleton(ThreadSafeSingleton): ...
+class DelegatedThreadSafeSingleton(ThreadSafeSingleton[T]): ...
 
 
-class ThreadLocalSingleton(BaseSingleton): ...
+class ThreadLocalSingleton(BaseSingleton[T]): ...
 
 
-class DelegatedThreadLocalSingleton(ThreadLocalSingleton): ...
+class DelegatedThreadLocalSingleton(ThreadLocalSingleton[T]): ...
 
 
-class AbstractSingleton(BaseSingleton):
+class AbstractSingleton(BaseSingleton[T]):
     def override(self, provider: BaseSingleton) -> OverridingContext: ...
 
 
@@ -259,19 +272,17 @@ class SingletonDelegate(Delegate):
     def __init__(self, factory: BaseSingleton): ...
 
 
-class List(Provider):
+class List(Provider[_List]):
     def __init__(self, *args: Injection): ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> _List[Any]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
-    def add_args(self, *args: Injection) -> List: ...
+    def add_args(self, *args: Injection) -> List[T]: ...
-    def set_args(self, *args: Injection) -> List: ...
+    def set_args(self, *args: Injection) -> List[T]: ...
-    def clear_args(self) -> List: ...
+    def clear_args(self) -> List[T]: ...
 
 
-class Dict(Provider):
+class Dict(Provider[_Dict]):
     def __init__(self, dict_: Optional[_Dict[Any, Injection]] = None, **kwargs: Injection): ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> _Dict[Any, Any]: ...
     @property
     def kwargs(self) -> _Dict[Any, Injection]: ...
     def add_kwargs(self, dict_: Optional[_Dict[Any, Injection]] = None, **kwargs: Injection) -> Dict: ...
@@ -279,42 +290,44 @@ class Dict(Provider):
     def clear_kwargs(self) -> Dict: ...
 
 
-class Resource(Provider, Generic[T]):
+class Resource(Provider[T]):
     @overload
-    def __init__(self, initializer: _Callable[..., resources.Resource[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, initializer: Type[resources.Resource[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    @overload
+    def __init__(self, initializer: Type[resources.AsyncResource[T]], *args: Injection, **kwargs: Injection) -> None: ...
     @overload
     def __init__(self, initializer: _Callable[..., _Iterator[T]], *args: Injection, **kwargs: Injection) -> None: ...
     @overload
+    def __init__(self, initializer: _Callable[..., _AsyncIterator[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    @overload
+    def __init__(self, initializer: _Callable[..., _Coroutine[Injection, Injection, T]], *args: Injection, **kwargs: Injection) -> None: ...
+    @overload
     def __init__(self, initializer: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
     @property
     def args(self) -> Tuple[Injection]: ...
-    def add_args(self, *args: Injection) -> Resource: ...
+    def add_args(self, *args: Injection) -> Resource[T]: ...
-    def set_args(self, *args: Injection) -> Resource: ...
+    def set_args(self, *args: Injection) -> Resource[T]: ...
-    def clear_args(self) -> Resource: ...
+    def clear_args(self) -> Resource[T]: ...
     @property
     def kwargs(self) -> _Dict[Any, Injection]: ...
-    def add_kwargs(self, **kwargs: Injection) -> Resource: ...
+    def add_kwargs(self, **kwargs: Injection) -> Resource[T]: ...
-    def set_kwargs(self, **kwargs: Injection) -> Resource: ...
+    def set_kwargs(self, **kwargs: Injection) -> Resource[T]: ...
-    def clear_kwargs(self) -> Resource: ...
+    def clear_kwargs(self) -> Resource[T]: ...
     @property
     def initialized(self) -> bool: ...
-    def init(self) -> T: ...
+    def init(self) -> Optional[Awaitable[T]]: ...
-    def shutdown(self) -> None: ...
+    def shutdown(self) -> Optional[Awaitable]: ...
 
 
-class Container(Provider):
+class Container(Provider[T]):
-
     def __init__(self, container_cls: Type[T], container: Optional[T] = None, **overriding_providers: Provider) -> None: ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
     def __getattr__(self, name: str) -> Provider: ...
     @property
     def container(self) -> T: ...
 
 
-class Selector(Provider):
+class Selector(Provider[Any]):
     def __init__(self, selector: _Callable[..., Any], **providers: Provider): ...
-    def __call__(self, *args: Injection, **kwargs: Injection) -> Any: ...
     def __getattr__(self, name: str) -> Provider: ...
     @property
     def providers(self) -> _Dict[str, Provider]: ...

src/dependency_injector/providers.pyx

@@ -3,6 +3,7 @@
 from __future__ import absolute_import
 
 import copy
+import functools
 import inspect
 import os
 import re
@@ -88,6 +89,11 @@ else:
             return parser
 
 
+cdef int ASYNC_MODE_UNDEFINED = 0
+cdef int ASYNC_MODE_ENABLED = 1
+cdef int ASYNC_MODE_DISABLED = 2
+
+
 cdef class Provider(object):
     """Base provider class.
 
@@ -148,6 +154,7 @@ cdef class Provider(object):
         """Initializer."""
         self.__overridden = tuple()
         self.__last_overriding = None
+        self.__async_mode = ASYNC_MODE_UNDEFINED
         super(Provider, self).__init__()
 
     def __call__(self, *args, **kwargs):
@@ -156,8 +163,24 @@ cdef class Provider(object):
         Callable interface implementation.
         """
         if self.__last_overriding is not None:
-            return self.__last_overriding(*args, **kwargs)
+            result = self.__last_overriding(*args, **kwargs)
-        return self._provide(args, kwargs)
+        else:
+            result = self._provide(args, kwargs)
+
+        if self.is_async_mode_disabled():
+            return result
+        elif self.is_async_mode_enabled():
+            if not __isawaitable(result):
+                future_result = asyncio.Future()
+                future_result.set_result(result)
+                return future_result
+            return result
+        elif self.is_async_mode_undefined():
+            if __isawaitable(result):
+                self.enable_async_mode()
+            else:
+                self.disable_async_mode()
+            return result
 
     def __deepcopy__(self, memo):
         """Create and return full copy of provider."""
@@ -254,6 +277,23 @@ cdef class Provider(object):
             self.__overridden = tuple()
             self.__last_overriding = None
 
+    def async_(self, *args, **kwargs):
+        """Return provided object asynchronously.
+
+        This method is a synonym of __call__().
+        It provides typing stubs for correct type checking with
+        `await` expression:
+
+        .. code-block:: python
+
+            database_provider: Provider[DatabaseConnection] = Resource(init_db_async)
+
+            async def main():
+                db: DatabaseConnection = await database_provider.async_()
+                ...
+        """
+        return self.__call__(*args, **kwargs)
+
     def delegate(self):
         """Return provider's delegate.
 
@@ -279,6 +319,33 @@ cdef class Provider(object):
         """Return :py:class:`ProvidedInstance` provider."""
         return ProvidedInstance(self)
 
+    def enable_async_mode(self):
+        """Enable async mode."""
+        self.__async_mode = ASYNC_MODE_ENABLED
+
+    def disable_async_mode(self):
+        """Disable async mode."""
+        self.__async_mode = ASYNC_MODE_DISABLED
+
+    def reset_async_mode(self):
+        """Reset async mode.
+
+        Provider will automatically set the mode on the next call.
+        """
+        self.__async_mode = ASYNC_MODE_UNDEFINED
+
+    def is_async_mode_enabled(self):
+        """Check if async mode is enabled."""
+        return self.__async_mode == ASYNC_MODE_ENABLED
+
+    def is_async_mode_disabled(self):
+        """Check if async mode is disabled."""
+        return self.__async_mode == ASYNC_MODE_DISABLED
+
+    def is_async_mode_undefined(self):
+        """Check if async mode is undefined."""
+        return self.__async_mode == ASYNC_MODE_UNDEFINED
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Providing strategy implementation.
 
@@ -472,18 +539,38 @@ cdef class Dependency(Provider):
 
         :rtype: object
         """
-        cdef object instance
-
         if self.__last_overriding is None:
             raise Error('Dependency is not defined')
 
-        instance = self.__last_overriding(*args, **kwargs)
+        result = self.__last_overriding(*args, **kwargs)
 
-        if not isinstance(instance, self.instance_of):
-            raise Error('{0} is not an '.format(instance) +
-                        'instance of {0}'.format(self.instance_of))
 
-        return instance
+        if self.is_async_mode_disabled():
+            self._check_instance_type(result)
+            return result
+        elif self.is_async_mode_enabled():
+            if __isawaitable(result):
+                future_result = asyncio.Future()
+                result = asyncio.ensure_future(result)
+                result.add_done_callback(functools.partial(self._async_provide, future_result))
+                return future_result
+            else:
+                self._check_instance_type(result)
+                future_result = asyncio.Future()
+                future_result.set_result(result)
+                return future_result
+        elif self.is_async_mode_undefined():
+            if __isawaitable(result):
+                self.enable_async_mode()
+
+                future_result = asyncio.Future()
+                result = asyncio.ensure_future(result)
+                result.add_done_callback(functools.partial(self._async_provide, future_result))
+                return future_result
+            else:
+                self.disable_async_mode()
+                self._check_instance_type(result)
+                return result
 
     def __str__(self):
         """Return string representation of provider.
@@ -514,6 +601,19 @@ cdef class Dependency(Provider):
         """
         return self.override(provider)
 
+    def _async_provide(self, future_result, future):
+        instance = future.result()
+        try:
+            self._check_instance_type(instance)
+        except Error as exception:
+            future_result.set_exception(exception)
+        else:
+            future_result.set_result(instance)
+
+    def _check_instance_type(self, instance):
+        if not isinstance(instance, self.instance_of):
+            raise Error('{0} is not an instance of {1}'.format(instance, self.instance_of))
+
 
 cdef class ExternalDependency(Dependency):
     """:py:class:`ExternalDependency` provider describes dependency interface.
@@ -904,7 +1004,7 @@ cdef class AbstractCallable(Callable):
         """
         if self.__last_overriding is None:
             raise Error('{0} must be overridden before calling'.format(self))
-        return self.__last_overriding(*args, **kwargs)
+        return super().__call__(*args, **kwargs)
 
     def override(self, provider):
         """Override provider with another provider.
@@ -1020,7 +1120,7 @@ cdef class AbstractCoroutine(Coroutine):
         """
         if self.__last_overriding is None:
             raise Error('{0} must be overridden before calling'.format(self))
-        return self.__last_overriding(*args, **kwargs)
+        return super().__call__(*args, **kwargs)
 
     def override(self, provider):
         """Override provider with another provider.
@@ -1790,7 +1890,7 @@ cdef class AbstractFactory(Factory):
         """
         if self.__last_overriding is None:
             raise Error('{0} must be overridden before calling'.format(self))
-        return self.__last_overriding(*args, **kwargs)
+        return super().__call__(*args, **kwargs)
 
     def override(self, provider):
         """Override provider with another provider.
@@ -1881,13 +1981,6 @@ cdef class FactoryAggregate(Provider):
 
         return copied
 
-    def __call__(self, factory_name, *args, **kwargs):
-        """Create new object using factory with provided name.
-
-        Callable interface implementation.
-        """
-        return self.__get_factory(factory_name)(*args, **kwargs)
-
     def __getattr__(self, factory_name):
         """Return aggregated factory."""
         return self.__get_factory(factory_name)
@@ -1915,6 +2008,19 @@ cdef class FactoryAggregate(Provider):
         raise Error(
             '{0} providers could not be overridden'.format(self.__class__))
 
+    cpdef object _provide(self, tuple args, dict kwargs):
+        try:
+            factory_name = args[0]
+        except IndexError:
+            try:
+                factory_name = kwargs.pop('factory_name')
+            except KeyError:
+                raise TypeError('Factory missing 1 required positional argument: \'factory_name\'')
+        else:
+            args = args[1:]
+
+        return self.__get_factory(factory_name)(*args, **kwargs)
+
     cdef Factory __get_factory(self, str factory_name):
         if factory_name not in self.__factories:
             raise NoSuchProviderError(
@@ -2075,6 +2181,16 @@ cdef class BaseSingleton(Provider):
         """
         raise NotImplementedError()
 
+    def _async_init_instance(self, future_result, result):
+        try:
+            instance = result.result()
+        except Exception as exception:
+            self.__storage = None
+            future_result.set_exception(exception)
+        else:
+            self.__storage = instance
+            future_result.set_result(instance)
+
 
 cdef class Singleton(BaseSingleton):
     """Singleton provider returns same instance on every call.
@@ -2122,13 +2238,24 @@ cdef class Singleton(BaseSingleton):
 
         :rtype: None
         """
+        if __isawaitable(self.__storage):
+            asyncio.ensure_future(self.__storage).cancel()
         self.__storage = None
 
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return single instance."""
         if self.__storage is None:
-            self.__storage = __factory_call(self.__instantiator,
+            instance = __factory_call(self.__instantiator, args, kwargs)
-                                            args, kwargs)
+
+            if __isawaitable(instance):
+                future_result = asyncio.Future()
+                instance = asyncio.ensure_future(instance)
+                instance.add_done_callback(functools.partial(self._async_init_instance, future_result))
+                self.__storage = future_result
+                return future_result
+
+            self.__storage = instance
+
         return self.__storage
 
 
@@ -2179,18 +2306,30 @@ cdef class ThreadSafeSingleton(BaseSingleton):
         :rtype: None
         """
         with self.__storage_lock:
+            if __isawaitable(self.__storage):
+                asyncio.ensure_future(self.__storage).cancel()
             self.__storage = None
 
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return single instance."""
-        storage = self.__storage
+        instance = self.__storage
-        if storage is None:
+
+        if instance is None:
             with self.__storage_lock:
                 if self.__storage is None:
-                    self.__storage = __factory_call(self.__instantiator,
+                    instance = __factory_call(self.__instantiator, args, kwargs)
-                                                    args, kwargs)
+
-                storage = self.__storage
+                    if __isawaitable(instance):
-        return storage
+                        future_result = asyncio.Future()
+                        instance = asyncio.ensure_future(instance)
+                        instance.add_done_callback(functools.partial(self._async_init_instance, future_result))
+                        self.__storage = future_result
+                        return future_result
+
+                    self.__storage = instance
+
+        return instance
 
 
 cdef class DelegatedThreadSafeSingleton(ThreadSafeSingleton):
@@ -2248,6 +2387,8 @@ cdef class ThreadLocalSingleton(BaseSingleton):
 
         :rtype: None
         """
+        if __isawaitable(self.__storage.instance):
+            asyncio.ensure_future(self.__storage.instance).cancel()
         del self.__storage.instance
 
     cpdef object _provide(self, tuple args, dict kwargs):
@@ -2258,10 +2399,28 @@ cdef class ThreadLocalSingleton(BaseSingleton):
             instance = self.__storage.instance
         except AttributeError:
             instance = __factory_call(self.__instantiator, args, kwargs)
+
+            if __isawaitable(instance):
+                future_result = asyncio.Future()
+                instance = asyncio.ensure_future(instance)
+                instance.add_done_callback(functools.partial(self._async_init_instance, future_result))
+                self.__storage.instance = future_result
+                return future_result
+
             self.__storage.instance = instance
         finally:
             return instance
 
+    def _async_init_instance(self, future_result, result):
+        try:
+            instance = result.result()
+        except Exception as exception:
+            del self.__storage.instance
+            future_result.set_exception(exception)
+        else:
+            self.__storage.instance = instance
+            future_result.set_result(instance)
+
 
 cdef class DelegatedThreadLocalSingleton(ThreadLocalSingleton):
     """Delegated thread-local singleton is injected "as is".
@@ -2302,7 +2461,7 @@ cdef class AbstractSingleton(BaseSingleton):
         """
         if self.__last_overriding is None:
             raise Error('{0} must be overridden before calling'.format(self))
-        return self.__last_overriding(*args, **kwargs)
+        return super().__call__(*args, **kwargs)
 
     def override(self, provider):
         """Override provider with another provider.
@@ -2705,18 +2864,30 @@ cdef class Resource(Provider):
     def shutdown(self):
         """Shutdown resource."""
         if not self.__initialized:
+            if self.is_async_mode_enabled():
+                result = asyncio.Future()
+                result.set_result(None)
+                return result
             return
 
         if self.__shutdowner:
             try:
-                self.__shutdowner(self.__resource)
+                shutdown = self.__shutdowner(self.__resource)
             except StopIteration:
                 pass
+            else:
+                if inspect.isawaitable(shutdown):
+                    return self._create_shutdown_future(shutdown)
 
         self.__resource = None
         self.__initialized = False
         self.__shutdowner = None
 
+        if self.is_async_mode_enabled():
+            result = asyncio.Future()
+            result.set_result(None)
+            return result
+
     cpdef object _provide(self, tuple args, dict kwargs):
         if self.__initialized:
             return self.__resource
@@ -2733,6 +2904,19 @@ cdef class Resource(Provider):
                 self.__kwargs_len,
             )
             self.__shutdowner = initializer.shutdown
+        elif self._is_async_resource_subclass(self.__initializer):
+            initializer = self.__initializer()
+            async_init = __call(
+                initializer.init,
+                args,
+                self.__args,
+                self.__args_len,
+                kwargs,
+                self.__kwargs,
+                self.__kwargs_len,
+            )
+            self.__initialized = True
+            return self._create_init_future(async_init, initializer.shutdown)
         elif inspect.isgeneratorfunction(self.__initializer):
             initializer = __call(
                 self.__initializer,
@@ -2745,6 +2929,30 @@ cdef class Resource(Provider):
             )
             self.__resource = next(initializer)
             self.__shutdowner = initializer.send
+        elif iscoroutinefunction(self.__initializer):
+            initializer = __call(
+                self.__initializer,
+                args,
+                self.__args,
+                self.__args_len,
+                kwargs,
+                self.__kwargs,
+                self.__kwargs_len,
+            )
+            self.__initialized = True
+            return self._create_init_future(initializer)
+        elif isasyncgenfunction(self.__initializer):
+            initializer = __call(
+                self.__initializer,
+                args,
+                self.__args,
+                self.__args_len,
+                kwargs,
+                self.__kwargs,
+                self.__kwargs_len,
+            )
+            self.__initialized = True
+            return self._create_init_future(initializer.__anext__(), initializer.asend)
         elif callable(self.__initializer):
             self.__resource = __call(
                 self.__initializer,
@@ -2761,6 +2969,45 @@ cdef class Resource(Provider):
         self.__initialized = True
         return self.__resource
 
+    def _create_init_future(self, future, shutdowner=None):
+        callback = self._async_init_callback
+        if shutdowner:
+            callback = functools.partial(callback, shutdowner=shutdowner)
+
+        future = asyncio.ensure_future(future)
+        future.add_done_callback(callback)
+        self.__resource = future
+
+        return future
+
+    def _async_init_callback(self, initializer, shutdowner=None):
+        try:
+            resource = initializer.result()
+        except Exception:
+            self.__initialized = False
+            raise
+        else:
+            self.__resource = resource
+            self.__shutdowner = shutdowner
+
+    def _create_shutdown_future(self, shutdown_future):
+        future = asyncio.Future()
+        shutdown_future = asyncio.ensure_future(shutdown_future)
+        shutdown_future.add_done_callback(functools.partial(self._async_shutdown_callback, future))
+        return future
+
+    def _async_shutdown_callback(self, future_result, shutdowner):
+        try:
+            shutdowner.result()
+        except StopAsyncIteration:
+            pass
+
+        self.__resource = None
+        self.__initialized = False
+        self.__shutdowner = None
+
+        future_result.set_result(None)
+
     @staticmethod
     def _is_resource_subclass(instance):
         if  sys.version_info < (3, 5):
@@ -2770,6 +3017,15 @@ cdef class Resource(Provider):
         from . import resources
         return issubclass(instance, resources.Resource)
 
+    @staticmethod
+    def _is_async_resource_subclass(instance):
+        if  sys.version_info < (3, 5):
+            return False
+        if not isinstance(instance, CLASS_TYPES):
+            return
+        from . import resources
+        return issubclass(instance, resources.AsyncResource)
+
 
 cdef class Container(Provider):
     """Container provider provides an instance of declarative container.
@@ -3037,8 +3293,18 @@ cdef class AttributeGetter(Provider):
 
     cpdef object _provide(self, tuple args, dict kwargs):
         provided = self.__provider(*args, **kwargs)
+        if __isawaitable(provided):
+            future_result = asyncio.Future()
+            provided = asyncio.ensure_future(provided)
+            provided.add_done_callback(functools.partial(self._async_provide, future_result))
+            return future_result
         return getattr(provided, self.__attribute)
 
+    def _async_provide(self, future_result, future):
+        provided = future.result()
+        result = getattr(provided, self.__attribute)
+        future_result.set_result(result)
+
 
 cdef class ItemGetter(Provider):
     """Provider that returns the item of the injected instance.
@@ -3087,8 +3353,18 @@ cdef class ItemGetter(Provider):
 
     cpdef object _provide(self, tuple args, dict kwargs):
         provided = self.__provider(*args, **kwargs)
+        if __isawaitable(provided):
+            future_result = asyncio.Future()
+            provided = asyncio.ensure_future(provided)
+            provided.add_done_callback(functools.partial(self._async_provide, future_result))
+            return future_result
         return provided[self.__item]
 
+    def _async_provide(self, future_result, future):
+        provided = future.result()
+        result = provided[self.__item]
+        future_result.set_result(result)
+
 
 cdef class MethodCaller(Provider):
     """Provider that calls the method of the injected instance.
@@ -3169,6 +3445,11 @@ cdef class MethodCaller(Provider):
 
     cpdef object _provide(self, tuple args, dict kwargs):
         call = self.__provider()
+        if __isawaitable(call):
+            future_result = asyncio.Future()
+            call = asyncio.ensure_future(call)
+            call.add_done_callback(functools.partial(self._async_provide, future_result, args, kwargs))
+            return future_result
         return __call(
             call,
             args,
@@ -3179,6 +3460,19 @@ cdef class MethodCaller(Provider):
             self.__kwargs_len,
         )
 
+    def _async_provide(self, future_result, args, kwargs, future):
+        call = future.result()
+        result = __call(
+            call,
+            args,
+            self.__args,
+            self.__args_len,
+            kwargs,
+            self.__kwargs,
+            self.__kwargs_len,
+        )
+        future_result.set_result(result)
+
 
 cdef class Injection(object):
     """Abstract injection class."""
@@ -3381,3 +3675,36 @@ def merge_dicts(dict1, dict2):
     result = dict1.copy()
     result.update(dict2)
     return result
+
+
+def isawaitable(obj):
+    """Check if object is a coroutine function.
+
+    Return False for any object in Python 3.4 or below.
+    """
+    try:
+        return inspect.isawaitable(obj)
+    except AttributeError:
+        return False
+
+
+def iscoroutinefunction(obj):
+    """Check if object is a coroutine function.
+
+    Return False for any object in Python 3.4 or below.
+    """
+    try:
+        return inspect.iscoroutinefunction(obj)
+    except AttributeError:
+        return False
+
+
+def isasyncgenfunction(obj):
+    """Check if object is an asynchronous generator function.
+
+    Return False for any object in Python 3.4 or below.
+    """
+    try:
+        return inspect.isasyncgenfunction(obj)
+    except AttributeError:
+        return False

src/dependency_injector/resources.py

@@ -29,3 +29,14 @@ class Resource(Generic[T], metaclass=ResourceMeta):
     @abc.abstractmethod
     def shutdown(self, resource: T) -> None:
         ...
+
+
+class AsyncResource(Generic[T], metaclass=ResourceMeta):
+
+    @abc.abstractmethod
+    async def init(self, *args, **kwargs) -> T:
+        ...
+
+    @abc.abstractmethod
+    async def shutdown(self, resource: T) -> None:
+        ...

src/dependency_injector/wiring.py

@@ -1,5 +1,6 @@
 """Wiring module."""
 
+import asyncio
 import functools
 import inspect
 import importlib
@@ -426,10 +427,20 @@ def _get_async_patched(fn):
     @functools.wraps(fn)
     async def _patched(*args, **kwargs):
         to_inject = kwargs.copy()
+        to_inject_await = []
+        to_close_await = []
         for injection, provider in _patched.__injections__.items():
             if injection not in kwargs \
                     or _is_fastapi_default_arg_injection(injection, kwargs):
-                to_inject[injection] = provider()
+                provide = provider()
+                if inspect.isawaitable(provide):
+                    to_inject_await.append((injection, provide))
+                else:
+                    to_inject[injection] = provide
+
+        async_to_inject = await asyncio.gather(*[provide for _, provide in to_inject_await])
+        for provide, (injection, _) in zip(async_to_inject, to_inject_await):
+            to_inject[injection] = provide
 
         result = await fn(*args, **to_inject)
 
@@ -439,7 +450,11 @@ def _get_async_patched(fn):
                 continue
             if not isinstance(provider, providers.Resource):
                 continue
-            provider.shutdown()
+            shutdown = provider.shutdown()
+            if inspect.isawaitable(shutdown):
+                to_close_await.append(shutdown)
+
+        await asyncio.gather(*to_close_await)
 
         return result
     return _patched

tests/typing/callable.py

@@ -50,3 +50,9 @@ animal7: Animal = provider7(1, 2, 3, b='1', c=2, e=0.0)
 
 # Test 8: to check the CallableDelegate __init__
 provider8 = providers.CallableDelegate(providers.Callable(lambda: None))
+
+# Test 9: to check the return type with await
+provider9 = providers.Callable(Cat)
+async def _async9() -> None:
+    animal1: Animal = await provider9(1, 2, 3, b='1', c=2, e=0.0)  # type: ignore
+    animal2: Animal = await provider9.async_(1, 2, 3, b='1', c=2, e=0.0)

tests/typing/delegate.py

@@ -4,3 +4,9 @@ from dependency_injector import providers
 # Test 1: to check the return type
 provider1 = providers.Delegate(providers.Provider())
 var1: providers.Provider = provider1()
+
+# Test 2: to check the return type with await
+provider2 = providers.Delegate(providers.Provider())
+async def _async2() -> None:
+    var1: providers.Provider = await provider2()  # type: ignore
+    var2: providers.Provider = await provider2.async_()

tests/typing/dependency.py

@@ -20,3 +20,9 @@ var1: Animal = provider1()
 # Test 2: to check the return type
 provider2 = providers.Dependency(instance_of=Animal)
 var2: Type[Animal] = provider2.instance_of
+
+# Test 3: to check the return type with await
+provider3 = providers.Dependency(instance_of=Animal)
+async def _async3() -> None:
+    var1: Animal = await provider3()  # type: ignore
+    var2: Animal = await provider3.async_()

tests/typing/dict.py

@@ -35,3 +35,13 @@ provider5 = providers.Dict(
     a2=providers.Factory(object),
 )
 provided5: providers.ProvidedInstance = provider5.provided
+
+
+# Test 6: to check the return type with await
+provider6 = providers.Dict(
+    a1=providers.Factory(object),
+    a2=providers.Factory(object),
+)
+async def _async3() -> None:
+    var1: Dict[Any, Any] = await provider6()  # type: ignore
+    var2: Dict[Any, Any] = await provider6.async_()

tests/typing/factory.py

@@ -66,3 +66,9 @@ val9: Any = provider9('a')
 # Test 10: to check the explicit typing
 factory10: providers.Provider[Animal] = providers.Factory(Cat)
 animal10: Animal = factory10()
+
+# Test 11: to check the return type with await
+provider11 = providers.Factory(Cat)
+async def _async11() -> None:
+    animal1: Animal = await provider11(1, 2, 3, b='1', c=2, e=0.0)  # type: ignore
+    animal2: Animal = await provider11.async_(1, 2, 3, b='1', c=2, e=0.0)

tests/typing/list.py

@@ -27,3 +27,12 @@ provided3: providers.ProvidedInstance = provider3.provided
 attr_getter3: providers.AttributeGetter = provider3.provided.attr
 item_getter3: providers.ItemGetter = provider3.provided['item']
 method_caller3: providers.MethodCaller = provider3.provided.method.call(123, arg=324)
+
+# Test 4: to check the return type with await
+provider4 = providers.List(
+    providers.Factory(object),
+    providers.Factory(object),
+)
+async def _async4() -> None:
+    var1: List[Any] = await provider4()  # type: ignore
+    var2: List[Any] = await provider4.async_()

tests/typing/object.py

@@ -11,3 +11,9 @@ provided2: providers.ProvidedInstance = provider2.provided
 attr_getter2: providers.AttributeGetter = provider2.provided.attr
 item_getter2: providers.ItemGetter = provider2.provided['item']
 method_caller2: providers.MethodCaller = provider2.provided.method.call(123, arg=324)
+
+# Test 3: to check the return type with await
+provider3 = providers.Object(int(3))
+async def _async3() -> None:
+    var1: int = await provider3()  # type: ignore
+    var2: int = await provider3.async_()

tests/typing/provider.py

@@ -4,3 +4,12 @@ from dependency_injector import providers
 # Test 1: to check .provided attribute
 provider1: providers.Provider[int] = providers.Object(1)
 provided: providers.ProvidedInstance = provider1.provided
+
+# Test 2: to check async mode API
+provider2: providers.Provider = providers.Provider()
+provider2.enable_async_mode()
+provider2.disable_async_mode()
+provider2.reset_async_mode()
+r1: bool = provider2.is_async_mode_enabled()
+r2: bool = provider2.is_async_mode_disabled()
+r3: bool = provider2.is_async_mode_undefined()

tests/typing/resource.py

@@ -1,4 +1,4 @@
-from typing import List, Iterator, Generator
+from typing import List, Iterator, Generator, AsyncIterator, AsyncGenerator
 
 from dependency_injector import providers, resources
 
@@ -41,3 +41,59 @@ class MyResource4(resources.Resource[List[int]]):
 
 provider4 = providers.Resource(MyResource4)
 var4: List[int] = provider4()
+
+
+# Test 5: to check the return type with async function
+async def init5() -> List[int]:
+    ...
+
+
+provider5 = providers.Resource(init5)
+
+
+async def _provide5() -> None:
+    var1: List[int] = await provider5()  # type: ignore
+    var2: List[int] = await provider5.async_()
+
+
+# Test 6: to check the return type with async iterator
+async def init6() -> AsyncIterator[List[int]]:
+    yield []
+
+
+provider6 = providers.Resource(init6)
+
+
+async def _provide6() -> None:
+    var1: List[int] = await provider6()  # type: ignore
+    var2: List[int] = await provider6.async_()
+
+
+# Test 7: to check the return type with async generator
+async def init7() -> AsyncGenerator[List[int], None]:
+    yield []
+
+
+provider7 = providers.Resource(init7)
+
+
+async def _provide7() -> None:
+    var1: List[int] = await provider7()  # type: ignore
+    var2: List[int] = await provider7.async_()
+
+
+# Test 8: to check the return type with async resource subclass
+class MyResource8(resources.AsyncResource[List[int]]):
+    async def init(self, *args, **kwargs) -> List[int]:
+        return []
+
+    async def shutdown(self, resource: List[int]) -> None:
+        ...
+
+
+provider8 = providers.Resource(MyResource8)
+
+
+async def _provide8() -> None:
+    var1: List[int] = await provider8()  # type: ignore
+    var2: List[int] = await provider8.async_()

tests/typing/selector.py

@@ -1,3 +1,5 @@
+from typing import Any
+
 from dependency_injector import providers
 
 
@@ -7,7 +9,7 @@ provider1 = providers.Selector(
     a=providers.Factory(object),
     b=providers.Factory(object),
 )
-var1: int = provider1()
+var1: Any = provider1()
 
 # Test 2: to check the provided instance interface
 provider2 = providers.Selector(
@@ -27,3 +29,13 @@ provider3 = providers.Selector(
     b=providers.Factory(object),
 )
 attr3: providers.Provider = provider3.a
+
+# Test 4: to check the return type with await
+provider4 = providers.Selector(
+    lambda: 'a',
+    a=providers.Factory(object),
+    b=providers.Factory(object),
+)
+async def _async4() -> None:
+    var1: Any = await provider4()  # type: ignore
+    var2: Any = await provider4.async_()

tests/typing/singleton.py

@@ -69,3 +69,9 @@ animal11: Animal = provider11(1, 2, 3, b='1', c=2, e=0.0)
 
 # Test 12: to check the SingletonDelegate __init__
 provider12 = providers.SingletonDelegate(providers.Singleton(object))
+
+# Test 13: to check the return type with await
+provider13 = providers.Singleton(Cat)
+async def _async13() -> None:
+    animal1: Animal = await provider13(1, 2, 3, b='1', c=2, e=0.0)  # type: ignore
+    animal2: Animal = await provider13.async_(1, 2, 3, b='1', c=2, e=0.0)

tests/unit/asyncutils.py

@@ -0,0 +1,57 @@
+"""Test utils."""
+
+import asyncio
+import contextlib
+import sys
+import gc
+import unittest
+
+
+def run(main):
+    loop = asyncio.get_event_loop()
+    return loop.run_until_complete(main)
+
+
+def setup_test_loop(
+        loop_factory=asyncio.new_event_loop
+) -> asyncio.AbstractEventLoop:
+    loop = loop_factory()
+    try:
+        module = loop.__class__.__module__
+        skip_watcher = 'uvloop' in module
+    except AttributeError:  # pragma: no cover
+        # Just in case
+        skip_watcher = True
+    asyncio.set_event_loop(loop)
+    if sys.platform != 'win32' and not skip_watcher:
+        policy = asyncio.get_event_loop_policy()
+        watcher = asyncio.SafeChildWatcher()  # type: ignore
+        watcher.attach_loop(loop)
+        with contextlib.suppress(NotImplementedError):
+            policy.set_child_watcher(watcher)
+    return loop
+
+
+def teardown_test_loop(loop: asyncio.AbstractEventLoop, fast: bool = False) -> None:
+    closed = loop.is_closed()
+    if not closed:
+        loop.call_soon(loop.stop)
+        loop.run_forever()
+        loop.close()
+
+    if not fast:
+        gc.collect()
+
+    asyncio.set_event_loop(None)
+
+
+class AsyncTestCase(unittest.TestCase):
+
+    def setUp(self):
+        self.loop = setup_test_loop()
+
+    def tearDown(self):
+        teardown_test_loop(self.loop)
+
+    def _run(self, f):
+        return self.loop.run_until_complete(f)

tests/unit/containers/test_dynamic_async_resources_py36.py

@@ -0,0 +1,71 @@
+"""Dependency injector dynamic container unit tests for async resources."""
+
+import unittest2 as unittest
+
+# Runtime import to get asyncutils module
+import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
+import sys
+sys.path.append(_TOP_DIR)
+
+from asyncutils import AsyncTestCase
+
+from dependency_injector import (
+    containers,
+    providers,
+)
+
+
+class AsyncResourcesTest(AsyncTestCase):
+
+    @unittest.skipIf(sys.version_info[:2] <= (3, 5), 'Async test')
+    def test_async_init_resources(self):
+        async def _init1():
+            _init1.init_counter += 1
+            yield
+            _init1.shutdown_counter += 1
+
+        _init1.init_counter = 0
+        _init1.shutdown_counter = 0
+
+        async def _init2():
+            _init2.init_counter += 1
+            yield
+            _init2.shutdown_counter += 1
+
+        _init2.init_counter = 0
+        _init2.shutdown_counter = 0
+
+        class Container(containers.DeclarativeContainer):
+            resource1 = providers.Resource(_init1)
+            resource2 = providers.Resource(_init2)
+
+        container = Container()
+        self.assertEqual(_init1.init_counter, 0)
+        self.assertEqual(_init1.shutdown_counter, 0)
+        self.assertEqual(_init2.init_counter, 0)
+        self.assertEqual(_init2.shutdown_counter, 0)
+
+        self._run(container.init_resources())
+        self.assertEqual(_init1.init_counter, 1)
+        self.assertEqual(_init1.shutdown_counter, 0)
+        self.assertEqual(_init2.init_counter, 1)
+        self.assertEqual(_init2.shutdown_counter, 0)
+
+        self._run(container.shutdown_resources())
+        self.assertEqual(_init1.init_counter, 1)
+        self.assertEqual(_init1.shutdown_counter, 1)
+        self.assertEqual(_init2.init_counter, 1)
+        self.assertEqual(_init2.shutdown_counter, 1)
+
+        self._run(container.init_resources())
+        self._run(container.shutdown_resources())
+        self.assertEqual(_init1.init_counter, 2)
+        self.assertEqual(_init1.shutdown_counter, 2)
+        self.assertEqual(_init2.init_counter, 2)
+        self.assertEqual(_init2.shutdown_counter, 2)

tests/unit/containers/test_dynamic_py2_py3.py

@@ -231,7 +231,3 @@ class DeclarativeContainerInstanceTests(unittest.TestCase):
         self.assertEqual(_init1.shutdown_counter, 2)
         self.assertEqual(_init2.init_counter, 2)
         self.assertEqual(_init2.shutdown_counter, 2)
-
-
-if __name__ == '__main__':
-    unittest.main()

tests/unit/providers/test_async_py36.py

@@ -0,0 +1,818 @@
+import asyncio
+import random
+import unittest
+
+from dependency_injector import containers, providers, errors
+
+# Runtime import to get asyncutils module
+import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
+import sys
+sys.path.append(_TOP_DIR)
+
+from asyncutils import AsyncTestCase
+
+
+RESOURCE1 = object()
+RESOURCE2 = object()
+
+
+async def init_resource(resource):
+    await asyncio.sleep(random.randint(1, 10) / 1000)
+    yield resource
+    await asyncio.sleep(random.randint(1, 10) / 1000)
+
+
+class Client:
+    def __init__(self, resource1: object, resource2: object) -> None:
+        self.resource1 = resource1
+        self.resource2 = resource2
+
+
+class Service:
+    def __init__(self, client: Client) -> None:
+        self.client = client
+
+
+class Container(containers.DeclarativeContainer):
+    resource1 = providers.Resource(init_resource, providers.Object(RESOURCE1))
+    resource2 = providers.Resource(init_resource, providers.Object(RESOURCE2))
+
+    client = providers.Factory(
+        Client,
+        resource1=resource1,
+        resource2=resource2,
+    )
+
+    service = providers.Factory(
+        Service,
+        client=client,
+    )
+
+
+class FactoryTests(AsyncTestCase):
+
+    def test_args_injection(self):
+        class ContainerWithArgs(containers.DeclarativeContainer):
+            resource1 = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            resource2 = providers.Resource(init_resource, providers.Object(RESOURCE2))
+
+            client = providers.Factory(
+                Client,
+                resource1,
+                resource2,
+            )
+
+            service = providers.Factory(
+                Service,
+                client,
+            )
+
+        container = ContainerWithArgs()
+
+        client1 = self._run(container.client())
+        client2 = self._run(container.client())
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, RESOURCE2)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, RESOURCE2)
+
+        service1 = self._run(container.service())
+        service2 = self._run(container.service())
+
+        self.assertIsInstance(service1, Service)
+        self.assertIsInstance(service1.client, Client)
+        self.assertIs(service1.client.resource1, RESOURCE1)
+        self.assertIs(service1.client.resource2, RESOURCE2)
+
+        self.assertIsInstance(service2, Service)
+        self.assertIsInstance(service2.client, Client)
+        self.assertIs(service2.client.resource1, RESOURCE1)
+        self.assertIs(service2.client.resource2, RESOURCE2)
+
+        self.assertIsNot(service1.client, service2.client)
+
+    def test_kwargs_injection(self):
+        container = Container()
+
+        client1 = self._run(container.client())
+        client2 = self._run(container.client())
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, RESOURCE2)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, RESOURCE2)
+
+        service1 = self._run(container.service())
+        service2 = self._run(container.service())
+
+        self.assertIsInstance(service1, Service)
+        self.assertIsInstance(service1.client, Client)
+        self.assertIs(service1.client.resource1, RESOURCE1)
+        self.assertIs(service1.client.resource2, RESOURCE2)
+
+        self.assertIsInstance(service2, Service)
+        self.assertIsInstance(service2.client, Client)
+        self.assertIs(service2.client.resource1, RESOURCE1)
+        self.assertIs(service2.client.resource2, RESOURCE2)
+
+        self.assertIsNot(service1.client, service2.client)
+
+    def test_context_kwargs_injection(self):
+        resource2_extra = object()
+
+        container = Container()
+
+        client1 = self._run(container.client(resource2=resource2_extra))
+        client2 = self._run(container.client(resource2=resource2_extra))
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, resource2_extra)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, resource2_extra)
+
+    def test_args_kwargs_injection(self):
+        class ContainerWithArgsAndKwArgs(containers.DeclarativeContainer):
+            resource1 = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            resource2 = providers.Resource(init_resource, providers.Object(RESOURCE2))
+
+            client = providers.Factory(
+                Client,
+                resource1,
+                resource2=resource2,
+            )
+
+            service = providers.Factory(
+                Service,
+                client=client,
+            )
+
+        container = ContainerWithArgsAndKwArgs()
+
+        client1 = self._run(container.client())
+        client2 = self._run(container.client())
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, RESOURCE2)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, RESOURCE2)
+
+        service1 = self._run(container.service())
+        service2 = self._run(container.service())
+
+        self.assertIsInstance(service1, Service)
+        self.assertIsInstance(service1.client, Client)
+        self.assertIs(service1.client.resource1, RESOURCE1)
+        self.assertIs(service1.client.resource2, RESOURCE2)
+
+        self.assertIsInstance(service2, Service)
+        self.assertIsInstance(service2.client, Client)
+        self.assertIs(service2.client.resource1, RESOURCE1)
+        self.assertIs(service2.client.resource2, RESOURCE2)
+
+        self.assertIsNot(service1.client, service2.client)
+
+    def test_attributes_injection(self):
+        class ContainerWithAttributes(containers.DeclarativeContainer):
+            resource1 = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            resource2 = providers.Resource(init_resource, providers.Object(RESOURCE2))
+
+            client = providers.Factory(
+                Client,
+                resource1,
+                resource2=None,
+            )
+            client.add_attributes(resource2=resource2)
+
+            service = providers.Factory(
+                Service,
+                client=None,
+            )
+            service.add_attributes(client=client)
+
+        container = ContainerWithAttributes()
+
+        client1 = self._run(container.client())
+        client2 = self._run(container.client())
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, RESOURCE2)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, RESOURCE2)
+
+        service1 = self._run(container.service())
+        service2 = self._run(container.service())
+
+        self.assertIsInstance(service1, Service)
+        self.assertIsInstance(service1.client, Client)
+        self.assertIs(service1.client.resource1, RESOURCE1)
+        self.assertIs(service1.client.resource2, RESOURCE2)
+
+        self.assertIsInstance(service2, Service)
+        self.assertIsInstance(service2.client, Client)
+        self.assertIs(service2.client.resource1, RESOURCE1)
+        self.assertIs(service2.client.resource2, RESOURCE2)
+
+        self.assertIsNot(service1.client, service2.client)
+
+
+class FactoryAggregateTests(AsyncTestCase):
+
+    def test_async_mode(self):
+        object1 = object()
+        object2 = object()
+
+        async def _get_object1():
+            return object1
+
+        def _get_object2():
+            return object2
+
+        provider = providers.FactoryAggregate(
+            object1=providers.Factory(_get_object1),
+            object2=providers.Factory(_get_object2),
+        )
+
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        created_object1 = self._run(provider('object1'))
+        self.assertIs(created_object1, object1)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        created_object2 = self._run(provider('object2'))
+        self.assertIs(created_object2, object2)
+
+
+class SingletonTests(AsyncTestCase):
+
+    def test_injections(self):
+        class ContainerWithSingletons(containers.DeclarativeContainer):
+            resource1 = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            resource2 = providers.Resource(init_resource, providers.Object(RESOURCE2))
+
+            client = providers.Singleton(
+                Client,
+                resource1=resource1,
+                resource2=resource2,
+            )
+
+            service = providers.Singleton(
+                Service,
+                client=client,
+            )
+
+        container = ContainerWithSingletons()
+
+        client1 = self._run(container.client())
+        client2 = self._run(container.client())
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, RESOURCE2)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, RESOURCE2)
+
+        service1 = self._run(container.service())
+        service2 = self._run(container.service())
+
+        self.assertIsInstance(service1, Service)
+        self.assertIsInstance(service1.client, Client)
+        self.assertIs(service1.client.resource1, RESOURCE1)
+        self.assertIs(service1.client.resource2, RESOURCE2)
+
+        self.assertIsInstance(service2, Service)
+        self.assertIsInstance(service2.client, Client)
+        self.assertIs(service2.client.resource1, RESOURCE1)
+        self.assertIs(service2.client.resource2, RESOURCE2)
+
+        self.assertIs(service1, service2)
+        self.assertIs(service1.client, service2.client)
+        self.assertIs(service1.client, client1)
+
+        self.assertIs(service2.client, client2)
+        self.assertIs(client1, client2)
+
+    def test_async_mode(self):
+        instance = object()
+
+        async def create_instance():
+            return instance
+
+        provider = providers.Singleton(create_instance)
+
+        instance1 = self._run(provider())
+        instance2 = self._run(provider())
+
+        self.assertIs(instance1, instance2)
+        self.assertIs(instance, instance)
+
+    def test_async_init_with_error(self):
+        # Disable default exception handling to prevent output
+        asyncio.get_event_loop().set_exception_handler(lambda loop, context: ...)
+
+        async def create_instance():
+            create_instance.counter += 1
+            raise RuntimeError()
+
+        create_instance.counter = 0
+
+        provider = providers.Singleton(create_instance)
+
+
+        future = provider()
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        with self.assertRaises(RuntimeError):
+            self._run(future)
+
+        self.assertEqual(create_instance.counter, 1)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        with self.assertRaises(RuntimeError):
+            self._run(provider())
+
+        self.assertEqual(create_instance.counter, 2)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        # Restore default exception handling
+        asyncio.get_event_loop().set_exception_handler(None)
+
+
+class DelegatedSingletonTests(AsyncTestCase):
+
+    def test_async_mode(self):
+        instance = object()
+
+        async def create_instance():
+            return instance
+
+        provider = providers.DelegatedSingleton(create_instance)
+
+        instance1 = self._run(provider())
+        instance2 = self._run(provider())
+
+        self.assertIs(instance1, instance2)
+        self.assertIs(instance, instance)
+
+
+class ThreadSafeSingletonTests(AsyncTestCase):
+
+    def test_async_mode(self):
+        instance = object()
+
+        async def create_instance():
+            return instance
+
+        provider = providers.ThreadSafeSingleton(create_instance)
+
+        instance1 = self._run(provider())
+        instance2 = self._run(provider())
+
+        self.assertIs(instance1, instance2)
+        self.assertIs(instance, instance)
+
+
+class DelegatedThreadSafeSingletonTests(AsyncTestCase):
+
+    def test_async_mode(self):
+        instance = object()
+
+        async def create_instance():
+            return instance
+
+        provider = providers.DelegatedThreadSafeSingleton(create_instance)
+
+        instance1 = self._run(provider())
+        instance2 = self._run(provider())
+
+        self.assertIs(instance1, instance2)
+        self.assertIs(instance, instance)
+
+
+class ThreadLocalSingletonTests(AsyncTestCase):
+
+    def test_async_mode(self):
+        instance = object()
+
+        async def create_instance():
+            return instance
+
+        provider = providers.ThreadLocalSingleton(create_instance)
+
+        instance1 = self._run(provider())
+        instance2 = self._run(provider())
+
+        self.assertIs(instance1, instance2)
+        self.assertIs(instance, instance)
+
+
+    def test_async_init_with_error(self):
+        # Disable default exception handling to prevent output
+        asyncio.get_event_loop().set_exception_handler(lambda loop, context: ...)
+
+        async def create_instance():
+            create_instance.counter += 1
+            raise RuntimeError()
+        create_instance.counter = 0
+
+        provider = providers.ThreadLocalSingleton(create_instance)
+
+        future = provider()
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        with self.assertRaises(RuntimeError):
+            self._run(future)
+
+        self.assertEqual(create_instance.counter, 1)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        with self.assertRaises(RuntimeError):
+            self._run(provider())
+
+        self.assertEqual(create_instance.counter, 2)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        # Restore default exception handling
+        asyncio.get_event_loop().set_exception_handler(None)
+
+
+class DelegatedThreadLocalSingletonTests(AsyncTestCase):
+
+    def test_async_mode(self):
+        instance = object()
+
+        async def create_instance():
+            return instance
+
+        provider = providers.DelegatedThreadLocalSingleton(create_instance)
+
+        instance1 = self._run(provider())
+        instance2 = self._run(provider())
+
+        self.assertIs(instance1, instance2)
+        self.assertIs(instance, instance)
+
+
+class ProvidedInstanceTests(AsyncTestCase):
+
+    def test_provided_attribute(self):
+        class TestClient:
+            def __init__(self, resource):
+                self.resource = resource
+
+        class TestService:
+            def __init__(self, resource):
+                self.resource = resource
+
+        class TestContainer(containers.DeclarativeContainer):
+            resource = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            client = providers.Factory(TestClient, resource=resource)
+            service = providers.Factory(TestService, resource=client.provided.resource)
+
+        container = TestContainer()
+
+        instance1, instance2 = self._run(
+            asyncio.gather(
+                container.service(),
+                container.service(),
+            ),
+        )
+
+        self.assertIs(instance1.resource, RESOURCE1)
+        self.assertIs(instance2.resource, RESOURCE1)
+        self.assertIs(instance1.resource, instance2.resource)
+
+    def test_provided_item(self):
+        class TestClient:
+            def __init__(self, resource):
+                self.resource = resource
+
+            def __getitem__(self, item):
+                return getattr(self, item)
+
+        class TestService:
+            def __init__(self, resource):
+                self.resource = resource
+
+        class TestContainer(containers.DeclarativeContainer):
+            resource = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            client = providers.Factory(TestClient, resource=resource)
+            service = providers.Factory(TestService, resource=client.provided['resource'])
+
+        container = TestContainer()
+
+        instance1, instance2 = self._run(
+            asyncio.gather(
+                container.service(),
+                container.service(),
+            ),
+        )
+
+        self.assertIs(instance1.resource, RESOURCE1)
+        self.assertIs(instance2.resource, RESOURCE1)
+        self.assertIs(instance1.resource, instance2.resource)
+
+    def test_provided_method_call(self):
+        class TestClient:
+            def __init__(self, resource):
+                self.resource = resource
+
+            def get_resource(self):
+                return self.resource
+
+        class TestService:
+            def __init__(self, resource):
+                self.resource = resource
+
+        class TestContainer(containers.DeclarativeContainer):
+            resource = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            client = providers.Factory(TestClient, resource=resource)
+            service = providers.Factory(TestService, resource=client.provided.get_resource.call())
+
+        container = TestContainer()
+
+        instance1, instance2 = self._run(
+            asyncio.gather(
+                container.service(),
+                container.service(),
+            ),
+        )
+
+        self.assertIs(instance1.resource, RESOURCE1)
+        self.assertIs(instance2.resource, RESOURCE1)
+        self.assertIs(instance1.resource, instance2.resource)
+
+
+class DependencyTests(AsyncTestCase):
+
+    def test_isinstance(self):
+        dependency = 1.0
+
+        async def get_async():
+            return dependency
+
+        provider = providers.Dependency(instance_of=float)
+        provider.override(providers.Callable(get_async))
+
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        dependency1 = self._run(provider())
+
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        dependency2 = self._run(provider())
+
+        self.assertEqual(dependency1, dependency)
+        self.assertEqual(dependency2, dependency)
+
+    def test_isinstance_invalid(self):
+        async def get_async():
+            return {}
+
+        provider = providers.Dependency(instance_of=float)
+        provider.override(providers.Callable(get_async))
+
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        with self.assertRaises(errors.Error):
+            self._run(provider())
+
+        self.assertTrue(provider.is_async_mode_enabled())
+
+    def test_async_mode(self):
+        dependency = 123
+
+        async def get_async():
+            return dependency
+
+        def get_sync():
+            return dependency
+
+        provider = providers.Dependency(instance_of=int)
+        provider.override(providers.Factory(get_async))
+
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        dependency1 = self._run(provider())
+
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        dependency2 = self._run(provider())
+        self.assertEqual(dependency1, dependency)
+        self.assertEqual(dependency2, dependency)
+
+        provider.override(providers.Factory(get_sync))
+
+        dependency3 = self._run(provider())
+
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        dependency4 = self._run(provider())
+        self.assertEqual(dependency3, dependency)
+        self.assertEqual(dependency4, dependency)
+
+
+class OverrideTests(AsyncTestCase):
+
+    def test_provider(self):
+        dependency = object()
+
+        async def _get_dependency_async():
+            return dependency
+
+        def _get_dependency_sync():
+            return dependency
+
+        provider = providers.Provider()
+
+        provider.override(providers.Callable(_get_dependency_async))
+        dependency1 = self._run(provider())
+
+        provider.override(providers.Callable(_get_dependency_sync))
+        dependency2 = self._run(provider())
+
+        self.assertIs(dependency1, dependency)
+        self.assertIs(dependency2, dependency)
+
+    def test_callable(self):
+        dependency = object()
+
+        async def _get_dependency_async():
+            return dependency
+
+        def _get_dependency_sync():
+            return dependency
+
+        provider = providers.Callable(_get_dependency_async)
+        dependency1 = self._run(provider())
+
+        provider.override(providers.Callable(_get_dependency_sync))
+        dependency2 = self._run(provider())
+
+        self.assertIs(dependency1, dependency)
+        self.assertIs(dependency2, dependency)
+
+    def test_factory(self):
+        dependency = object()
+
+        async def _get_dependency_async():
+            return dependency
+
+        def _get_dependency_sync():
+            return dependency
+
+        provider = providers.Factory(_get_dependency_async)
+        dependency1 = self._run(provider())
+
+        provider.override(providers.Callable(_get_dependency_sync))
+        dependency2 = self._run(provider())
+
+        self.assertIs(dependency1, dependency)
+        self.assertIs(dependency2, dependency)
+
+    def test_async_mode_enabling(self):
+        dependency = object()
+
+        async def _get_dependency_async():
+            return dependency
+
+        provider = providers.Callable(_get_dependency_async)
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        self._run(provider())
+
+        self.assertTrue(provider.is_async_mode_enabled())
+
+    def test_async_mode_disabling(self):
+        dependency = object()
+
+        def _get_dependency():
+            return dependency
+
+        provider = providers.Callable(_get_dependency)
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        provider()
+
+        self.assertTrue(provider.is_async_mode_disabled())
+
+    def test_async_mode_enabling_on_overriding(self):
+        dependency = object()
+
+        async def _get_dependency_async():
+            return dependency
+
+        provider = providers.Provider()
+        provider.override(providers.Callable(_get_dependency_async))
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        self._run(provider())
+
+        self.assertTrue(provider.is_async_mode_enabled())
+
+    def test_async_mode_disabling_on_overriding(self):
+        dependency = object()
+
+        def _get_dependency():
+            return dependency
+
+        provider = providers.Provider()
+        provider.override(providers.Callable(_get_dependency))
+        self.assertTrue(provider.is_async_mode_undefined())
+
+        provider()
+
+        self.assertTrue(provider.is_async_mode_disabled())
+
+
+class TestAsyncModeApi(unittest.TestCase):
+
+    def setUp(self):
+        self.provider = providers.Provider()
+
+    def test_default_mode(self):
+        self.assertFalse(self.provider.is_async_mode_enabled())
+        self.assertFalse(self.provider.is_async_mode_disabled())
+        self.assertTrue(self.provider.is_async_mode_undefined())
+
+    def test_enable(self):
+        self.provider.enable_async_mode()
+
+        self.assertTrue(self.provider.is_async_mode_enabled())
+        self.assertFalse(self.provider.is_async_mode_disabled())
+        self.assertFalse(self.provider.is_async_mode_undefined())
+
+    def test_disable(self):
+        self.provider.disable_async_mode()
+
+        self.assertFalse(self.provider.is_async_mode_enabled())
+        self.assertTrue(self.provider.is_async_mode_disabled())
+        self.assertFalse(self.provider.is_async_mode_undefined())
+
+    def test_reset(self):
+        self.provider.enable_async_mode()
+
+        self.assertTrue(self.provider.is_async_mode_enabled())
+        self.assertFalse(self.provider.is_async_mode_disabled())
+        self.assertFalse(self.provider.is_async_mode_undefined())
+
+        self.provider.reset_async_mode()
+
+        self.assertFalse(self.provider.is_async_mode_enabled())
+        self.assertFalse(self.provider.is_async_mode_disabled())
+        self.assertTrue(self.provider.is_async_mode_undefined())
+
+
+class AsyncTypingStubTests(AsyncTestCase):
+
+    def test_async_(self):
+        container = Container()
+
+        client1 = self._run(container.client.async_())
+        client2 = self._run(container.client.async_())
+
+        self.assertIsInstance(client1, Client)
+        self.assertIs(client1.resource1, RESOURCE1)
+        self.assertIs(client1.resource2, RESOURCE2)
+
+        self.assertIsInstance(client2, Client)
+        self.assertIs(client2.resource1, RESOURCE1)
+        self.assertIs(client2.resource2, RESOURCE2)
+
+        service1 = self._run(container.service.async_())
+        service2 = self._run(container.service.async_())
+
+        self.assertIsInstance(service1, Service)
+        self.assertIsInstance(service1.client, Client)
+        self.assertIs(service1.client.resource1, RESOURCE1)
+        self.assertIs(service1.client.resource2, RESOURCE2)
+
+        self.assertIsInstance(service2, Service)
+        self.assertIsInstance(service2.client, Client)
+        self.assertIs(service2.client.resource1, RESOURCE1)
+        self.assertIs(service2.client.resource2, RESOURCE2)
+
+        self.assertIsNot(service1.client, service2.client)

tests/unit/providers/test_coroutines_py35.py

@@ -1,9 +1,6 @@
 """Dependency injector coroutine providers unit tests."""
 
 import asyncio
-import contextlib
-import sys
-import gc
 
 import unittest2 as unittest
 
@@ -12,6 +9,19 @@ from dependency_injector import (
     errors,
 )
 
+# Runtime import to get asyncutils module
+import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
+import sys
+sys.path.append(_TOP_DIR)
+
+from asyncutils import AsyncTestCase
+
 
 async def _example(arg1, arg2, arg3, arg4):
     future = asyncio.Future()
@@ -25,52 +35,6 @@ def run(main):
     return loop.run_until_complete(main)
 
 
-def setup_test_loop(
-        loop_factory=asyncio.new_event_loop
-) -> asyncio.AbstractEventLoop:
-    loop = loop_factory()
-    try:
-        module = loop.__class__.__module__
-        skip_watcher = 'uvloop' in module
-    except AttributeError:  # pragma: no cover
-        # Just in case
-        skip_watcher = True
-    asyncio.set_event_loop(loop)
-    if sys.platform != "win32" and not skip_watcher:
-        policy = asyncio.get_event_loop_policy()
-        watcher = asyncio.SafeChildWatcher()  # type: ignore
-        watcher.attach_loop(loop)
-        with contextlib.suppress(NotImplementedError):
-            policy.set_child_watcher(watcher)
-    return loop
-
-
-def teardown_test_loop(loop: asyncio.AbstractEventLoop,
-                       fast: bool=False) -> None:
-    closed = loop.is_closed()
-    if not closed:
-        loop.call_soon(loop.stop)
-        loop.run_forever()
-        loop.close()
-
-    if not fast:
-        gc.collect()
-
-    asyncio.set_event_loop(None)
-
-
-class AsyncTestCase(unittest.TestCase):
-
-    def setUp(self):
-        self.loop = setup_test_loop()
-
-    def tearDown(self):
-        teardown_test_loop(self.loop)
-
-    def _run(self, f):
-        return self.loop.run_until_complete(f)
-
-
 class CoroutineTests(AsyncTestCase):
 
     def test_init_with_coroutine(self):

tests/unit/providers/test_factories_py2_py3.py

@@ -520,6 +520,24 @@ class FactoryAggregateTests(unittest.TestCase):
         self.assertEqual(object_b.init_arg3, 33)
         self.assertEqual(object_b.init_arg4, 44)
 
+    def test_call_factory_name_as_kwarg(self):
+        object_a = self.factory_aggregate(
+            factory_name='example_a',
+            init_arg1=1,
+            init_arg2=2,
+            init_arg3=3,
+            init_arg4=4,
+        )
+        self.assertIsInstance(object_a, self.ExampleA)
+        self.assertEqual(object_a.init_arg1, 1)
+        self.assertEqual(object_a.init_arg2, 2)
+        self.assertEqual(object_a.init_arg3, 3)
+        self.assertEqual(object_a.init_arg4, 4)
+
+    def test_call_no_factory_name(self):
+        with self.assertRaises(TypeError):
+            self.factory_aggregate()
+
     def test_call_no_such_provider(self):
         with self.assertRaises(errors.NoSuchProviderError):
             self.factory_aggregate('unknown')

tests/unit/providers/test_resource_py35.py

@@ -1,11 +1,24 @@
 """Dependency injector resource provider unit tests."""
 
-import sys
+import asyncio
 
 import unittest2 as unittest
 
 from dependency_injector import containers, providers, resources, errors
 
+# Runtime import to get asyncutils module
+import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
+import sys
+sys.path.append(_TOP_DIR)
+
+from asyncutils import AsyncTestCase
+
 
 def init_fn(*args, **kwargs):
     return args, kwargs
@@ -156,6 +169,15 @@ class ResourceTests(unittest.TestCase):
         self.assertEqual(_init.init_counter, 2)
         self.assertEqual(_init.shutdown_counter, 2)
 
+    def test_shutdown_of_not_initialized(self):
+        def _init():
+            yield
+
+        provider = providers.Resource(_init)
+
+        result = provider.shutdown()
+        self.assertIsNone(result)
+
     def test_initialized(self):
         provider = providers.Resource(init_fn)
         self.assertFalse(provider.initialized)
@@ -320,3 +342,186 @@ class ResourceTests(unittest.TestCase):
                 provider.initialized,
             )
         )
+
+
+class AsyncResourceTest(AsyncTestCase):
+
+    def test_init_async_function(self):
+        resource = object()
+
+        async def _init():
+            await asyncio.sleep(0.001)
+            _init.counter += 1
+            return resource
+        _init.counter = 0
+
+        provider = providers.Resource(_init)
+
+        result1 = self._run(provider())
+        self.assertIs(result1, resource)
+        self.assertEqual(_init.counter, 1)
+
+        result2 = self._run(provider())
+        self.assertIs(result2, resource)
+        self.assertEqual(_init.counter, 1)
+
+        self._run(provider.shutdown())
+
+    def test_init_async_generator(self):
+        resource = object()
+
+        async def _init():
+            await asyncio.sleep(0.001)
+            _init.init_counter += 1
+
+            yield resource
+
+            await asyncio.sleep(0.001)
+            _init.shutdown_counter += 1
+
+        _init.init_counter = 0
+        _init.shutdown_counter = 0
+
+        provider = providers.Resource(_init)
+
+        result1 = self._run(provider())
+        self.assertIs(result1, resource)
+        self.assertEqual(_init.init_counter, 1)
+        self.assertEqual(_init.shutdown_counter, 0)
+
+        self._run(provider.shutdown())
+        self.assertEqual(_init.init_counter, 1)
+        self.assertEqual(_init.shutdown_counter, 1)
+
+        result2 = self._run(provider())
+        self.assertIs(result2, resource)
+        self.assertEqual(_init.init_counter, 2)
+        self.assertEqual(_init.shutdown_counter, 1)
+
+        self._run(provider.shutdown())
+        self.assertEqual(_init.init_counter, 2)
+        self.assertEqual(_init.shutdown_counter, 2)
+
+    def test_init_async_class(self):
+        resource = object()
+
+        class TestResource(resources.AsyncResource):
+            init_counter = 0
+            shutdown_counter = 0
+
+            async def init(self):
+                await asyncio.sleep(0.001)
+                self.__class__.init_counter += 1
+                return resource
+
+            async def shutdown(self, resource_):
+                await asyncio.sleep(0.001)
+                self.__class__.shutdown_counter += 1
+                assert resource_ is resource
+
+        provider = providers.Resource(TestResource)
+
+        result1 = self._run(provider())
+        self.assertIs(result1, resource)
+        self.assertEqual(TestResource.init_counter, 1)
+        self.assertEqual(TestResource.shutdown_counter, 0)
+
+        self._run(provider.shutdown())
+        self.assertEqual(TestResource.init_counter, 1)
+        self.assertEqual(TestResource.shutdown_counter, 1)
+
+        result2 = self._run(provider())
+        self.assertIs(result2, resource)
+        self.assertEqual(TestResource.init_counter, 2)
+        self.assertEqual(TestResource.shutdown_counter, 1)
+
+        self._run(provider.shutdown())
+        self.assertEqual(TestResource.init_counter, 2)
+        self.assertEqual(TestResource.shutdown_counter, 2)
+
+    def test_init_with_error(self):
+        async def _init():
+            raise RuntimeError()
+
+        provider = providers.Resource(_init)
+
+        future = provider()
+        self.assertTrue(provider.initialized)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+        # Disable default exception handling to prevent output
+        asyncio.get_event_loop().set_exception_handler(lambda loop, context: ...)
+
+        with self.assertRaises(RuntimeError):
+            self._run(future)
+
+        # Restore default exception handling
+        asyncio.get_event_loop().set_exception_handler(None)
+
+        self.assertFalse(provider.initialized)
+        self.assertTrue(provider.is_async_mode_enabled())
+
+    def test_init_and_shutdown_methods(self):
+        async def _init():
+            await asyncio.sleep(0.001)
+            _init.init_counter += 1
+
+            yield
+
+            await asyncio.sleep(0.001)
+            _init.shutdown_counter += 1
+
+        _init.init_counter = 0
+        _init.shutdown_counter = 0
+
+        provider = providers.Resource(_init)
+
+        self._run(provider.init())
+        self.assertEqual(_init.init_counter, 1)
+        self.assertEqual(_init.shutdown_counter, 0)
+
+        self._run(provider.shutdown())
+        self.assertEqual(_init.init_counter, 1)
+        self.assertEqual(_init.shutdown_counter, 1)
+
+        self._run(provider.init())
+        self.assertEqual(_init.init_counter, 2)
+        self.assertEqual(_init.shutdown_counter, 1)
+
+        self._run(provider.shutdown())
+        self.assertEqual(_init.init_counter, 2)
+        self.assertEqual(_init.shutdown_counter, 2)
+
+    def test_shutdown_of_not_initialized(self):
+        async def _init():
+            yield
+
+        provider = providers.Resource(_init)
+        provider.enable_async_mode()
+
+        result = self._run(provider.shutdown())
+        self.assertIsNone(result)
+
+    def test_concurrent_init(self):
+        resource = object()
+
+        async def _init():
+            await asyncio.sleep(0.001)
+            _init.counter += 1
+            return resource
+        _init.counter = 0
+
+        provider = providers.Resource(_init)
+
+        result1, result2 = self._run(
+            asyncio.gather(
+                provider(),
+                provider()
+            ),
+        )
+
+        self.assertIs(result1, resource)
+        self.assertEqual(_init.counter, 1)
+
+        self.assertIs(result2, resource)
+        self.assertEqual(_init.counter, 1)

tests/unit/samples/wiringsamples/asyncinjections.py

@@ -0,0 +1,50 @@
+import asyncio
+
+from dependency_injector import containers, providers
+from dependency_injector.wiring import inject, Provide, Closing
+
+
+class TestResource:
+    def __init__(self):
+        self.init_counter = 0
+        self.shutdown_counter = 0
+
+    def reset_counters(self):
+        self.init_counter = 0
+        self.shutdown_counter = 0
+
+
+resource1 = TestResource()
+resource2 = TestResource()
+
+
+async def async_resource(resource):
+    await asyncio.sleep(0.001)
+    resource.init_counter += 1
+
+    yield resource
+
+    await asyncio.sleep(0.001)
+    resource.shutdown_counter += 1
+
+
+class Container(containers.DeclarativeContainer):
+
+    resource1 = providers.Resource(async_resource, providers.Object(resource1))
+    resource2 = providers.Resource(async_resource, providers.Object(resource2))
+
+
+@inject
+async def async_injection(
+        resource1: object = Provide[Container.resource1],
+        resource2: object = Provide[Container.resource2],
+):
+    return resource1, resource2
+
+
+@inject
+async def async_injection_with_closing(
+        resource1: object = Closing[Provide[Container.resource1]],
+        resource2: object = Closing[Provide[Container.resource2]],
+):
+    return resource1, resource2

tests/unit/wiring/test_wiring_py36.py

@@ -5,6 +5,12 @@ from dependency_injector.wiring import wire, Provide, Closing
 
 # Runtime import to avoid syntax errors in samples on Python < 3.5
 import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
 _SAMPLES_DIR = os.path.abspath(
     os.path.sep.join((
         os.path.dirname(__file__),
@@ -12,8 +18,11 @@ _SAMPLES_DIR = os.path.abspath(
     )),
 )
 import sys
+sys.path.append(_TOP_DIR)
 sys.path.append(_SAMPLES_DIR)
 
+from asyncutils import AsyncTestCase
+
 from wiringsamples import module, package
 from wiringsamples.service import Service
 from wiringsamples.container import Container, SubContainer
@@ -267,3 +276,56 @@ class WiringAndFastAPITest(unittest.TestCase):
         self.assertEqual(result_2.shutdown_counter, 2)
 
         self.assertIsNot(result_1, result_2)
+
+
+class WiringAsyncInjectionsTest(AsyncTestCase):
+
+    def test_async_injections(self):
+        from wiringsamples import asyncinjections
+
+        container = asyncinjections.Container()
+        container.wire(modules=[asyncinjections])
+        self.addCleanup(container.unwire)
+
+        asyncinjections.resource1.reset_counters()
+        asyncinjections.resource2.reset_counters()
+
+        resource1, resource2 = self._run(asyncinjections.async_injection())
+
+        self.assertIs(resource1, asyncinjections.resource1)
+        self.assertEqual(asyncinjections.resource1.init_counter, 1)
+        self.assertEqual(asyncinjections.resource1.shutdown_counter, 0)
+
+        self.assertIs(resource2, asyncinjections.resource2)
+        self.assertEqual(asyncinjections.resource2.init_counter, 1)
+        self.assertEqual(asyncinjections.resource2.shutdown_counter, 0)
+
+    def test_async_injections_with_closing(self):
+        from wiringsamples import asyncinjections
+
+        container = asyncinjections.Container()
+        container.wire(modules=[asyncinjections])
+        self.addCleanup(container.unwire)
+
+        asyncinjections.resource1.reset_counters()
+        asyncinjections.resource2.reset_counters()
+
+        resource1, resource2 = self._run(asyncinjections.async_injection_with_closing())
+
+        self.assertIs(resource1, asyncinjections.resource1)
+        self.assertEqual(asyncinjections.resource1.init_counter, 1)
+        self.assertEqual(asyncinjections.resource1.shutdown_counter, 1)
+
+        self.assertIs(resource2, asyncinjections.resource2)
+        self.assertEqual(asyncinjections.resource2.init_counter, 1)
+        self.assertEqual(asyncinjections.resource2.shutdown_counter, 1)
+
+        resource1, resource2 = self._run(asyncinjections.async_injection_with_closing())
+
+        self.assertIs(resource1, asyncinjections.resource1)
+        self.assertEqual(asyncinjections.resource1.init_counter, 2)
+        self.assertEqual(asyncinjections.resource1.shutdown_counter, 2)
+
+        self.assertIs(resource2, asyncinjections.resource2)
+        self.assertEqual(asyncinjections.resource2.init_counter, 2)
+        self.assertEqual(asyncinjections.resource2.shutdown_counter, 2)

tests/unit/wiring/test_wiringfastapi_py36.py

@@ -1,13 +1,13 @@
-import asyncio
-import contextlib
-import gc
-import unittest
-from unittest import mock
-
 from httpx import AsyncClient
 
-# Runtime import to avoid syntax errors in samples on Python < 3.5
+# Runtime import to avoid syntax errors in samples on Python < 3.5 and reach top-dir
 import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
 _SAMPLES_DIR = os.path.abspath(
     os.path.sep.join((
         os.path.dirname(__file__),
@@ -15,58 +15,14 @@ _SAMPLES_DIR = os.path.abspath(
     )),
 )
 import sys
+sys.path.append(_TOP_DIR)
 sys.path.append(_SAMPLES_DIR)
 
+from asyncutils import AsyncTestCase
+
 from wiringfastapi import web
 
 
-# TODO: Refactor to use common async test case
-def setup_test_loop(
-        loop_factory=asyncio.new_event_loop
-) -> asyncio.AbstractEventLoop:
-    loop = loop_factory()
-    try:
-        module = loop.__class__.__module__
-        skip_watcher = 'uvloop' in module
-    except AttributeError:  # pragma: no cover
-        # Just in case
-        skip_watcher = True
-    asyncio.set_event_loop(loop)
-    if sys.platform != "win32" and not skip_watcher:
-        policy = asyncio.get_event_loop_policy()
-        watcher = asyncio.SafeChildWatcher()  # type: ignore
-        watcher.attach_loop(loop)
-        with contextlib.suppress(NotImplementedError):
-            policy.set_child_watcher(watcher)
-    return loop
-
-
-def teardown_test_loop(loop: asyncio.AbstractEventLoop,
-                       fast: bool=False) -> None:
-    closed = loop.is_closed()
-    if not closed:
-        loop.call_soon(loop.stop)
-        loop.run_forever()
-        loop.close()
-
-    if not fast:
-        gc.collect()
-
-    asyncio.set_event_loop(None)
-
-
-class AsyncTestCase(unittest.TestCase):
-
-    def setUp(self):
-        self.loop = setup_test_loop()
-
-    def tearDown(self):
-        teardown_test_loop(self.loop)
-
-    def _run(self, f):
-        return self.loop.run_until_complete(f)
-
-
 class WiringFastAPITest(AsyncTestCase):
 
     client: AsyncClient