Bump version to 4.0.0a2

* Refactor wiring

* Add todos to wiring

* Implement wiring of config invariant

* Implement sub containers wiring + add tests

* Add test for wiring config invariant

README.rst

@@ -74,31 +74,39 @@ Key features of the ``Dependency Injector``:
 
 .. code-block:: python
 
-   from dependency_injector import containers, providers
+    from dependency_injector import containers, providers
+    from dependency_injector.wiring import Provide
 
 
-   class Container(containers.DeclarativeContainer):
+    class Container(containers.DeclarativeContainer):
 
-       config = providers.Configuration()
+        config = providers.Configuration()
 
-       api_client = providers.Singleton(
-           ApiClient,
-           api_key=config.api_key,
-           timeout=config.timeout.as_int(),
-       )
+        api_client = providers.Singleton(
+            ApiClient,
+            api_key=config.api_key,
+            timeout=config.timeout.as_int(),
+        )
 
-       service = providers.Factory(
-           Service,
-           api_client=api_client,
-       )
+        service = providers.Factory(
+            Service,
+            api_client=api_client,
+        )
 
 
-   if __name__ == '__main__':
-       container = Container()
-       container.config.api_key.from_env('API_KEY')
-       container.config.timeout.from_env('TIMEOUT')
+    def main(service: Service = Provide[Container.service]):
+        ...
 
-       service = container.service()
+
+    if __name__ == '__main__':
+        container = Container()
+
+        container.config.api_key.from_env('API_KEY')
+        container.config.timeout.from_env('TIMEOUT')
+
+        container.wire(modules=[sys.modules[__name__]])
+
+        main()
 
 With the ``Dependency Injector`` you keep **application structure in one place**.
 This place is called **the container**. You use the container to manage all the components of the

docs/index.rst

@@ -83,31 +83,39 @@ Key features of the ``Dependency Injector``:
 
 .. code-block:: python
 
-   from dependency_injector import containers, providers
+    from dependency_injector import containers, providers
+    from dependency_injector.wiring import Provide
 
 
-   class Container(containers.DeclarativeContainer):
+    class Container(containers.DeclarativeContainer):
 
-       config = providers.Configuration()
+        config = providers.Configuration()
 
-       api_client = providers.Singleton(
-           ApiClient,
-           api_key=config.api_key,
-           timeout=config.timeout.as_int(),
-       )
+        api_client = providers.Singleton(
+            ApiClient,
+            api_key=config.api_key,
+            timeout=config.timeout.as_int(),
+        )
 
-       service = providers.Factory(
-           Service,
-           api_client=api_client,
-       )
+        service = providers.Factory(
+            Service,
+            api_client=api_client,
+        )
 
 
-   if __name__ == '__main__':
-       container = Container()
-       container.config.api_key.from_env('API_KEY')
-       container.config.timeout.from_env('TIMEOUT')
+    def main(service: Service = Provide[Container.service]):
+        ...
 
-       service = container.service()
+
+    if __name__ == '__main__':
+        container = Container()
+
+        container.config.api_key.from_env('API_KEY')
+        container.config.timeout.from_env('TIMEOUT')
+
+        container.wire(modules=[sys.modules[__name__]])
+
+        main()
 
 With the ``Dependency Injector`` you keep **application structure in one place**.
 This place is called **the container**. You use the container to manage all the components of the

docs/main/changelog.rst

@@ -7,6 +7,17 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+4.0.0
+-----
+- Add ``wiring`` feature.
+- Deprecate ``ext.aiohttp`` module.
+- Deprecate ``ext.flask`` module.
+- Remove deprecated ``types`` module.
+- Deprecate ``.delegate()`` provider method in favor of ``.provider`` attribute.
+- Add ``sanic`` example.
+- Update ``aiohttp`` example.
+- Update ``flask`` example.
+
 3.44.0
 ------
 - Add native support of the generics to the providers: ``some_provider = providers.Provider[SomeClass]``.

examples/demo/demo.py

@@ -1,17 +1,10 @@
+import sys
+from unittest import mock
+
 from dependency_injector import containers, providers
+from dependency_injector.wiring import Provide
 
-
-class ApiClient:
-
-    def __init__(self, api_key: str, timeout: int):
-        self.api_key = api_key
-        self.timeout = timeout
-
-
-class Service:
-
-    def __init__(self, api_client: ApiClient):
-        self.api_client = api_client
+from di import ApiClient, Service
 
 
 class Container(containers.DeclarativeContainer):
@@ -30,9 +23,19 @@ class Container(containers.DeclarativeContainer):
     )
 
 
+def main(service: Service = Provide[Container.service]):
+    ...
+
+
 if __name__ == '__main__':
     container = Container()
+
     container.config.api_key.from_env('API_KEY')
     container.config.timeout.from_env('TIMEOUT')
 
-    service = container.service()
+    container.wire(modules=[sys.modules[__name__]])
+
+    main()
+
+    with container.api_client.override(mock.Mock()):
+        main()

examples/demo/di.py

@@ -14,5 +14,15 @@ class Service:
         self.api_client = api_client
 
 
+def main() -> None:
+    service = Service(
+        api_client=ApiClient(
+            api_key=os.getenv('API_KEY'),
+            timeout=os.getenv('TIMEOUT'),
+        ),
+    )
+    ...
+
+
 if __name__ == '__main__':
-    service = Service(ApiClient(os.getenv('API_KEY'), os.getenv('TIMEOUT')))
+    main()

examples/demo/example.py

@@ -14,5 +14,10 @@ class Service:
         self.api_client = ApiClient()
 
 
-if __name__ == '__main__':
+def main() -> None:
     service = Service()
+    ...
+
+
+if __name__ == '__main__':
+    main()

examples/di_demo/test.py

@@ -1,11 +0,0 @@
-from unittest import mock
-
-from demo import Container
-
-
-if __name__ == '__main__':
-    container = Container()
-
-    with container.api_client.override(mock.Mock()):
-        service = container.service()
-        assert isinstance(service.api_client, mock.Mock)

examples/miniapps/aiohttp/README.rst

@@ -1,8 +1,8 @@
-Aiohttp Dependency Injection Example
-====================================
+Dependency Injector + Aiohttp Example
+=====================================
 
 Application ``giphynavigator`` is an `Aiohttp <https://docs.aiohttp.org/>`_ +
-`Dependency Injector <http://python-dependency-injector.ets-labs.org/>`_ application.
+`Dependency Injector <http://python-dependency-injector.ets-labs.org/>`_ example application.
 
 Run
 ---
@@ -107,11 +107,11 @@ The output should be something like:
    ---------------------------------------------------
    giphynavigator/__init__.py          0      0   100%
    giphynavigator/__main__.py          5      5     0%
-   giphynavigator/application.py      10      0   100%
-   giphynavigator/containers.py       10      0   100%
+   giphynavigator/application.py      12      0   100%
+   giphynavigator/containers.py        6      0   100%
    giphynavigator/giphy.py            14      9    36%
+   giphynavigator/handlers.py          9      0   100%
    giphynavigator/services.py          9      1    89%
-   giphynavigator/tests.py            35      0   100%
-   giphynavigator/views.py             7      0   100%
+   giphynavigator/tests.py            37      0   100%
    ---------------------------------------------------
-   TOTAL                              90     15    83%
+   TOTAL                              92     15    84%

examples/miniapps/aiohttp/config.yml

@@ -0,0 +1,5 @@
+giphy:
+  request_timeout: 10
+default:
+  query: "Dependency Injector"
+  limit: 10

examples/miniapps/aiohttp/giphynavigator/application.py

@@ -2,20 +2,23 @@
 
 from aiohttp import web
 
-from .containers import ApplicationContainer
+from .containers import Container
+from . import handlers
 
 
 def create_app():
     """Create and return aiohttp application."""
-    container = ApplicationContainer()
+    container = Container()
     container.config.from_yaml('config.yml')
     container.config.giphy.api_key.from_env('GIPHY_API_KEY')
 
-    app: web.Application = container.app()
+    container.wire(modules=[handlers])
+
+    app = web.Application()
     app.container = container
 
     app.add_routes([
-        web.get('/', container.index_view.as_view()),
+        web.get('/', handlers.index),
     ])
 
     return app

examples/miniapps/aiohttp/giphynavigator/containers.py

@@ -0,0 +1,21 @@
+"""Containers module."""
+
+from dependency_injector import containers, providers
+
+from . import giphy, services
+
+
+class Container(containers.DeclarativeContainer):
+
+    config = providers.Configuration()
+
+    giphy_client = providers.Factory(
+        giphy.GiphyClient,
+        api_key=config.giphy.api_key,
+        timeout=config.giphy.request_timeout,
+    )
+
+    search_service = providers.Factory(
+        services.SearchService,
+        giphy_client=giphy_client,
+    )

examples/miniapps/aiohttp/giphynavigator/handlers.py

@@ -1,15 +1,17 @@
-"""Views module."""
+"""Handlers module."""
 
 from aiohttp import web
+from dependency_injector.wiring import Provide
 
 from .services import SearchService
+from .containers import Container
 
 
 async def index(
         request: web.Request,
-        search_service: SearchService,
-        default_query: str,
-        default_limit: int,
+        search_service: SearchService = Provide[Container.search_service],
+        default_query: str = Provide[Container.config.default.query],
+        default_limit: int = Provide[Container.config.default.limit.as_int()],
 ) -> web.Response:
     query = request.query.get('query', default_query)
     limit = int(request.query.get('limit', default_limit))

examples/miniapps/aiohttp/giphynavigator/tests.py

@@ -10,7 +10,9 @@ from giphynavigator.giphy import GiphyClient
 
 @pytest.fixture
 def app():
-    return create_app()
+    app = create_app()
+    yield app
+    app.container.unwire()
 
 
 @pytest.fixture
@@ -73,5 +75,5 @@ async def test_index_default_params(client, app):
 
     assert response.status == 200
     data = await response.json()
-    assert data['query'] == app.container.config.search.default_query()
-    assert data['limit'] == app.container.config.search.default_limit()
+    assert data['query'] == app.container.config.default.query()
+    assert data['limit'] == app.container.config.default.limit()

examples/miniapps/flask/README.rst

@@ -1,8 +1,8 @@
-Flask Dependency Injection Example
-==================================
+Dependency Injector + Flask Example
+===================================
 
 Application ``githubnavigator`` is a `Flask <https://flask.palletsprojects.com/>`_ +
-`Dependency Injector <http://python-dependency-injector.ets-labs.org/>`_ application.
+`Dependency Injector <http://python-dependency-injector.ets-labs.org/>`_ example application.
 
 .. image:: screenshot.png
 
@@ -90,10 +90,10 @@ The output should be something like:
    Name                             Stmts   Miss  Cover
    ----------------------------------------------------
    githubnavigator/__init__.py          0      0   100%
-   githubnavigator/application.py      11      0   100%
-   githubnavigator/containers.py       13      0   100%
+   githubnavigator/application.py      15      0   100%
+   githubnavigator/containers.py        7      0   100%
    githubnavigator/services.py         14      0   100%
-   githubnavigator/tests.py            32      0   100%
-   githubnavigator/views.py             7      0   100%
+   githubnavigator/tests.py            34      0   100%
+   githubnavigator/views.py             9      0   100%
    ----------------------------------------------------
-   TOTAL                               77      0   100%
+   TOTAL                               79      0   100%

examples/miniapps/flask/config.yml

@@ -0,0 +1,5 @@
+github:
+  request_timeout: 10
+default:
+  query: "Dependency Injector"
+  limit: 10

examples/miniapps/flask/githubnavigator/application.py

@@ -0,0 +1,25 @@
+"""Application module."""
+
+from flask import Flask
+from flask_bootstrap import Bootstrap
+
+from .containers import Container
+from . import views
+
+
+def create_app():
+    container = Container()
+    container.config.from_yaml('config.yml')
+    container.config.github.auth_token.from_env('GITHUB_TOKEN')
+
+    container.wire(modules=[views])
+
+    app = Flask(__name__)
+    app.container = container
+
+    bootstrap = Bootstrap()
+    bootstrap.init_app(app)
+
+    app.add_url_rule('/', 'index', views.index)
+
+    return app

examples/miniapps/flask/githubnavigator/containers.py

@@ -0,0 +1,22 @@
+"""Application containers module."""
+
+from dependency_injector import containers, providers
+from github import Github
+
+from . import services
+
+
+class Container(containers.DeclarativeContainer):
+
+    config = providers.Configuration()
+
+    github_client = providers.Factory(
+        Github,
+        login_or_token=config.github.auth_token,
+        timeout=config.github.request_timeout,
+    )
+
+    search_service = providers.Factory(
+        services.SearchService,
+        github_client=github_client,
+    )

examples/miniapps/flask/githubnavigator/tests.py

@@ -11,7 +11,9 @@ from .application import create_app
 
 @pytest.fixture
 def app():
-    return create_app()
+    app = create_app()
+    yield app
+    app.container.unwire()
 
 
 def test_index(client, app):

examples/miniapps/flask/githubnavigator/views.py

@@ -1,14 +1,16 @@
 """Views module."""
 
 from flask import request, render_template
+from dependency_injector.wiring import Provide
 
 from .services import SearchService
+from .containers import Container
 
 
 def index(
-        search_service: SearchService,
-        default_query: str,
-        default_limit: int,
+        search_service: SearchService = Provide[Container.search_service],
+        default_query: str = Provide[Container.config.default.query],
+        default_limit: int = Provide[Container.config.default.limit.as_int()],
 ):
     query = request.args.get('query', default_query)
     limit = request.args.get('limit', default_limit, int)

examples/miniapps/ghnav-flask/config.yml

@@ -1,5 +0,0 @@
-github:
-  request_timeout: 10
-search:
-  default_query: "Dependency Injector"
-  default_limit: 10

examples/miniapps/ghnav-flask/githubnavigator/application.py

@@ -1,20 +0,0 @@
-"""Application module."""
-
-from .containers import ApplicationContainer
-
-
-def create_app():
-    """Create and return Flask application."""
-    container = ApplicationContainer()
-    container.config.from_yaml('config.yml')
-    container.config.github.auth_token.from_env('GITHUB_TOKEN')
-
-    app = container.app()
-    app.container = container
-
-    bootstrap = container.bootstrap()
-    bootstrap.init_app(app)
-
-    app.add_url_rule('/', view_func=container.index_view.as_view())
-
-    return app

examples/miniapps/ghnav-flask/githubnavigator/containers.py

@@ -1,37 +0,0 @@
-"""Application containers module."""
-
-from dependency_injector import containers, providers
-from dependency_injector.ext import flask
-from flask import Flask
-from flask_bootstrap import Bootstrap
-from github import Github
-
-from . import views, services
-
-
-class ApplicationContainer(containers.DeclarativeContainer):
-    """Application container."""
-
-    app = flask.Application(Flask, __name__)
-
-    bootstrap = flask.Extension(Bootstrap)
-
-    config = providers.Configuration()
-
-    github_client = providers.Factory(
-        Github,
-        login_or_token=config.github.auth_token,
-        timeout=config.github.request_timeout,
-    )
-
-    search_service = providers.Factory(
-        services.SearchService,
-        github_client=github_client,
-    )
-
-    index_view = flask.View(
-        views.index,
-        search_service=search_service,
-        default_query=config.search.default_query,
-        default_limit=config.search.default_limit,
-    )

examples/miniapps/giphynav-aiohttp/config.yml

@@ -1,5 +0,0 @@
-giphy:
-  request_timeout: 10
-search:
-  default_query: "Dependency Injector"
-  default_limit: 10

examples/miniapps/giphynav-aiohttp/giphynavigator/containers.py

@@ -1,33 +0,0 @@
-"""Application containers module."""
-
-from dependency_injector import containers, providers
-from dependency_injector.ext import aiohttp
-from aiohttp import web
-
-from . import giphy, services, views
-
-
-class ApplicationContainer(containers.DeclarativeContainer):
-    """Application container."""
-
-    app = aiohttp.Application(web.Application)
-
-    config = providers.Configuration()
-
-    giphy_client = providers.Factory(
-        giphy.GiphyClient,
-        api_key=config.giphy.api_key,
-        timeout=config.giphy.request_timeout,
-    )
-
-    search_service = providers.Factory(
-        services.SearchService,
-        giphy_client=giphy_client,
-    )
-
-    index_view = aiohttp.View(
-        views.index,
-        search_service=search_service,
-        default_query=config.search.default_query,
-        default_limit=config.search.default_limit,
-    )

examples/miniapps/sanic/README.rst

@@ -0,0 +1,117 @@
+Dependency Injector + Sanic Example
+=====================================
+
+Application ``giphynavigator`` is a `Sanic <https://sanic.readthedocs.io/en/latest/index.html>`_ +
+`Dependency Injector <http://python-dependency-injector.ets-labs.org/>`_ example application.
+
+Run
+---
+
+Create virtual environment:
+
+.. code-block:: bash
+
+   virtualenv venv
+   . venv/bin/activate
+
+Install requirements:
+
+.. code-block:: bash
+
+    pip install -r requirements.txt
+
+To run the application do:
+
+.. code-block:: bash
+
+    export GIPHY_API_KEY=wBJ2wZG7SRqfrU9nPgPiWvORmloDyuL0
+    python -m giphynavigator
+
+The output should be something like:
+
+.. code-block::
+
+   [2020-09-23 18:16:31 -0400] [48258] [INFO] Goin' Fast @ http://0.0.0.0:8000
+   [2020-09-23 18:16:31 -0400] [48258] [INFO] Starting worker [48258]
+
+After that visit http://127.0.0.1:8000/ in your browser or use CLI command (``curl``, ``httpie``,
+etc). You should see something like:
+
+.. code-block:: json
+
+   {
+       "query": "Dependency Injector",
+       "limit": 10,
+       "gifs": [
+           {
+               "url": "https://giphy.com/gifs/boxes-dependent-swbf2-6Eo7KzABxgJMY"
+           },
+           {
+               "url": "https://giphy.com/gifs/depends-J56qCcOhk6hKE"
+           },
+           {
+               "url": "https://giphy.com/gifs/web-series-ccstudios-bro-dependent-1lhU8KAVwmVVu"
+           },
+           {
+               "url": "https://giphy.com/gifs/TheBoysTV-friends-friend-weneedeachother-XxR9qcIwcf5Jq404Sx"
+           },
+           {
+               "url": "https://giphy.com/gifs/netflix-a-series-of-unfortunate-events-asoue-9rgeQXbwoK53pcxn7f"
+           },
+           {
+               "url": "https://giphy.com/gifs/black-and-white-sad-skins-Hs4YzLs2zJuLu"
+           },
+           {
+               "url": "https://giphy.com/gifs/always-there-for-you-i-am-here-PlayjhCco9jHBYrd9w"
+           },
+           {
+               "url": "https://giphy.com/gifs/stream-famous-dollar-YT2dvOByEwXCdoYiA1"
+           },
+           {
+               "url": "https://giphy.com/gifs/i-love-you-there-for-am-1BhGzgpZXYWwWMAGB1"
+           },
+           {
+               "url": "https://giphy.com/gifs/life-like-twerk-9hlnWxjHqmH28"
+           }
+       ]
+   }
+
+.. note::
+
+   To create your own Giphy API key follow this
+   `guide <https://support.giphy.com/hc/en-us/articles/360020283431-Request-A-GIPHY-API-Key>`_.
+
+Test
+----
+
+This application comes with the unit tests.
+
+To run the tests do:
+
+.. code-block:: bash
+
+   py.test giphynavigator/tests.py --cov=giphynavigator
+
+The output should be something like:
+
+.. code-block::
+
+   platform darwin -- Python 3.8.3, pytest-5.4.3, py-1.9.0, pluggy-0.13.1
+   plugins: cov-2.10.0, sanic-1.6.1
+   collected 3 items
+
+   giphynavigator/tests.py ...                                     [100%]
+
+   ---------- coverage: platform darwin, python 3.8.3-final-0 -----------
+   Name                            Stmts   Miss  Cover
+   ---------------------------------------------------
+   giphynavigator/__init__.py          0      0   100%
+   giphynavigator/__main__.py          4      4     0%
+   giphynavigator/application.py      12      0   100%
+   giphynavigator/containers.py        6      0   100%
+   giphynavigator/giphy.py            14      9    36%
+   giphynavigator/handlers.py         10      0   100%
+   giphynavigator/services.py          9      1    89%
+   giphynavigator/tests.py            34      0   100%
+   ---------------------------------------------------
+   TOTAL                              89     14    84%

examples/miniapps/sanic/config.yml

@@ -0,0 +1,5 @@
+giphy:
+  request_timeout: 10
+default:
+  query: "Dependency Injector"
+  limit: 10

examples/miniapps/sanic/giphynavigator/__init__.py

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

examples/miniapps/sanic/giphynavigator/__main__.py

@@ -0,0 +1,8 @@
+"""Main module."""
+
+from .application import create_app
+
+
+if __name__ == '__main__':
+    app = create_app()
+    app.run(host='0.0.0.0', port=8000, debug=True)

examples/miniapps/sanic/giphynavigator/application.py

@@ -0,0 +1,22 @@
+"""Application module."""
+
+from sanic import Sanic
+
+from .containers import Container
+from . import handlers
+
+
+def create_app():
+    """Create and return aiohttp application."""
+    container = Container()
+    container.config.from_yaml('config.yml')
+    container.config.giphy.api_key.from_env('GIPHY_API_KEY')
+
+    container.wire(modules=[handlers])
+
+    app = Sanic('Giphy Navigator')
+    app.container = container
+
+    app.add_route(handlers.index, '/')
+
+    return app

examples/miniapps/sanic/giphynavigator/containers.py

@@ -0,0 +1,21 @@
+"""Containers module."""
+
+from dependency_injector import containers, providers
+
+from . import giphy, services
+
+
+class Container(containers.DeclarativeContainer):
+
+    config = providers.Configuration()
+
+    giphy_client = providers.Factory(
+        giphy.GiphyClient,
+        api_key=config.giphy.api_key,
+        timeout=config.giphy.request_timeout,
+    )
+
+    search_service = providers.Factory(
+        services.SearchService,
+        giphy_client=giphy_client,
+    )

examples/miniapps/sanic/giphynavigator/giphy.py

@@ -0,0 +1,26 @@
+"""Giphy client module."""
+
+from aiohttp import ClientSession, ClientTimeout
+
+
+class GiphyClient:
+
+    API_URL = 'http://api.giphy.com/v1'
+
+    def __init__(self, api_key, timeout):
+        self._api_key = api_key
+        self._timeout = ClientTimeout(timeout)
+
+    async def search(self, query, limit):
+        """Make search API call and return result."""
+        url = f'{self.API_URL}/gifs/search'
+        params = {
+            'q': query,
+            'api_key': self._api_key,
+            'limit': limit,
+        }
+        async with ClientSession(timeout=self._timeout) as session:
+            async with session.get(url, params=params) as response:
+                if response.status != 200:
+                    response.raise_for_status()
+                return await response.json()

examples/miniapps/sanic/giphynavigator/handlers.py

@@ -0,0 +1,28 @@
+"""Handlers module."""
+
+from sanic.request import Request
+from sanic.response import HTTPResponse, json
+from dependency_injector.wiring import Provide
+
+from .services import SearchService
+from .containers import Container
+
+
+async def index(
+        request: Request,
+        search_service: SearchService = Provide[Container.search_service],
+        default_query: str = Provide[Container.config.default.query],
+        default_limit: int = Provide[Container.config.default.limit.as_int()],
+) -> HTTPResponse:
+    query = request.args.get('query', default_query)
+    limit = int(request.args.get('limit', default_limit))
+
+    gifs = await search_service.search(query, limit)
+
+    return json(
+        {
+            'query': query,
+            'limit': limit,
+            'gifs': gifs,
+        },
+    )

examples/miniapps/sanic/giphynavigator/services.py

@@ -0,0 +1,18 @@
+"""Services module."""
+
+from .giphy import GiphyClient
+
+
+class SearchService:
+
+    def __init__(self, giphy_client: GiphyClient):
+        self._giphy_client = giphy_client
+
+    async def search(self, query, limit):
+        """Search for gifs and return formatted data."""
+        if not query:
+            return []
+
+        result = await self._giphy_client.search(query, limit)
+
+        return [{'url': gif['url']} for gif in result['data']]

examples/miniapps/sanic/giphynavigator/tests.py

@@ -0,0 +1,74 @@
+"""Tests module."""
+
+from unittest import mock
+
+import pytest
+
+from giphynavigator.application import create_app
+from giphynavigator.giphy import GiphyClient
+
+
+@pytest.fixture
+def app():
+    app = create_app()
+    yield app
+    app.container.unwire()
+
+
+async def test_index(app):
+    giphy_client_mock = mock.AsyncMock(spec=GiphyClient)
+    giphy_client_mock.search.return_value = {
+        'data': [
+            {'url': 'https://giphy.com/gif1.gif'},
+            {'url': 'https://giphy.com/gif2.gif'},
+        ],
+    }
+
+    with app.container.giphy_client.override(giphy_client_mock):
+        _, response = await app.asgi_client.get(
+            '/',
+            params={
+                'query': 'test',
+                'limit': 10,
+            },
+        )
+
+    assert response.status == 200
+    data = response.json()
+    assert data == {
+        'query': 'test',
+        'limit': 10,
+        'gifs': [
+            {'url': 'https://giphy.com/gif1.gif'},
+            {'url': 'https://giphy.com/gif2.gif'},
+        ],
+    }
+
+
+async def test_index_no_data(app):
+    giphy_client_mock = mock.AsyncMock(spec=GiphyClient)
+    giphy_client_mock.search.return_value = {
+        'data': [],
+    }
+
+    with app.container.giphy_client.override(giphy_client_mock):
+        _, response = await app.asgi_client.get('/')
+
+    assert response.status == 200
+    data = response.json()
+    assert data['gifs'] == []
+
+
+async def test_index_default_params(app):
+    giphy_client_mock = mock.AsyncMock(spec=GiphyClient)
+    giphy_client_mock.search.return_value = {
+        'data': [],
+    }
+
+    with app.container.giphy_client.override(giphy_client_mock):
+        _, response = await app.asgi_client.get('/')
+
+    assert response.status == 200
+    data = response.json()
+    assert data['query'] == app.container.config.default.query()
+    assert data['limit'] == app.container.config.default.limit()

examples/miniapps/sanic/requirements.txt

@@ -0,0 +1,5 @@
+dependency-injector
+sanic
+pyyaml
+pytest-sanic
+pytest-cov

setup.cfg

@@ -2,6 +2,8 @@
 max_line_length = 100
 max_complexity = 10
 exclude = types.py
+per-file-ignores =
+    examples/demo/*: F841
 
 [pydocstyle]
 ignore = D100,D101,D102,D105,D106,D107,D203,D213

src/dependency_injector/__init__.py

@@ -1,6 +1,6 @@
 """Top-level package."""
 
-__version__ = '3.44.0'
+__version__ = '4.0.0a2'
 """Version number.
 
 :type: str

src/dependency_injector/containers.pyi

@@ -1,4 +1,5 @@
-from typing import Type, Dict, Tuple, Optional, Any, Union, ClassVar, Callable as _Callable
+from types import ModuleType
+from typing import Type, Dict, Tuple, Optional, Any, Union, ClassVar, Callable as _Callable, Iterable
 
 from .providers import Provider
 
@@ -16,6 +17,9 @@ class Container:
     def override_providers(self, **overriding_providers: Provider) -> None: ...
     def reset_last_overriding(self) -> None: ...
     def reset_override(self) -> None: ...
+    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: ...
 
 
 class DynamicContainer(Container): ...

src/dependency_injector/containers.pyx

@@ -1,15 +1,26 @@
 """Containers module."""
 
+import sys
+
 import six
 
 from .errors import Error
-
 from .providers cimport (
     Provider,
     deepcopy,
 )
 
 
+if sys.version_info[:2] >= (3, 6):
+    from .wiring import wire, unwire
+else:
+    def wire(*args, **kwargs):
+        raise NotImplementedError('Wiring requires Python 3.6 or above')
+
+    def unwire(*args, **kwargs):
+        raise NotImplementedError('Wiring requires Python 3.6 or above')
+
+
 class DynamicContainer(object):
     """Dynamic inversion of control container.
 
@@ -47,8 +58,11 @@ class DynamicContainer(object):
         :rtype: None
         """
         self.provider_type = Provider
-        self.providers = dict()
+        self.providers = {}
         self.overridden = tuple()
+        self.declarative_parent = None
+        self.wired_to_modules = []
+        self.wired_to_packages = []
         super(DynamicContainer, self).__init__()
 
     def __deepcopy__(self, memo):
@@ -60,6 +74,7 @@ class DynamicContainer(object):
         copied = self.__class__()
         copied.provider_type = Provider
         copied.overridden = deepcopy(self.overridden, memo)
+        copied.declarative_parent = self.declarative_parent
 
         for name, provider in deepcopy(self.providers, memo).items():
             setattr(copied, name, provider)
@@ -171,6 +186,34 @@ class DynamicContainer(object):
         for provider in six.itervalues(self.providers):
             provider.reset_override()
 
+    def wire(self, modules=None, packages=None):
+        """Wire container providers with provided packages and modules.
+
+        :rtype: None
+        """
+        wire(
+            container=self,
+            modules=modules,
+            packages=packages,
+        )
+
+        if modules:
+            self.wired_to_modules.extend(modules)
+
+        if packages:
+            self.wired_to_packages.extend(packages)
+
+    def unwire(self):
+        """Unwire container providers from previously wired packages and modules."""
+        unwire(
+            modules=self.wired_to_modules,
+            packages=self.wired_to_packages,
+        )
+
+        self.wired_to_modules.clear()
+        self.wired_to_packages.clear()
+
+
 
 class DeclarativeContainerMetaClass(type):
     """Declarative inversion of control container meta class."""
@@ -310,6 +353,7 @@ class DeclarativeContainer(object):
         """
         container = cls.instance_type()
         container.provider_type = cls.provider_type
+        container.declarative_parent = cls
         container.set_providers(**deepcopy(cls.providers))
         container.override_providers(**overriding_providers)
         return container
@@ -363,6 +407,15 @@ class DeclarativeContainer(object):
         for provider in six.itervalues(cls.providers):
             provider.reset_override()
 
+    @classmethod
+    def resolve_provider_name(cls, provider_to_resolve):
+        """Try to resolve provider name by its instance."""
+        for provider_name, container_provider in cls.providers.items():
+            if container_provider is provider_to_resolve:
+                return provider_name
+        else:
+            return None
+
 
 def override(object container):
     """:py:class:`DeclarativeContainer` overriding decorator.

src/dependency_injector/ext/aiohttp.py

@@ -3,10 +3,18 @@
 from __future__ import absolute_import
 
 import functools
+import warnings
 
 from dependency_injector import providers
 
 
+warnings.warn(
+    'Module "dependency_injector.ext.aiohttp" is deprecated since '
+    'version 4.0.0. Use "dependency_injector.wiring" module instead.',
+    category=DeprecationWarning,
+)
+
+
 class Application(providers.Singleton):
     """Aiohttp application provider."""
 

src/dependency_injector/ext/flask.py

@@ -1,12 +1,20 @@
 """Flask extension module."""
 
 from __future__ import absolute_import
+import warnings
 
 from flask import request as flask_request
 
 from dependency_injector import providers, errors
 
 
+warnings.warn(
+    'Module "dependency_injector.ext.aiohttp" is deprecated since '
+    'version 4.0.0. Use "dependency_injector.wiring" module instead.',
+    category=DeprecationWarning,
+)
+
+
 request = providers.Object(flask_request)
 
 

src/dependency_injector/providers.pxd

@@ -93,6 +93,10 @@ cdef class ConfigurationOption(Provider):
     cdef object __cache
 
 
+cdef class TypedConfigurationOption(Callable):
+    pass
+
+
 cdef class Configuration(Object):
     cdef str __name
     cdef dict __children
@@ -181,9 +185,9 @@ cdef class List(Provider):
 
 
 cdef class Container(Provider):
-    cdef object container_cls
-    cdef dict overriding_providers
-    cdef object container
+    cdef object __container_cls
+    cdef dict __overriding_providers
+    cdef object __container
 
     cpdef object _provide(self, tuple args, dict kwargs)
 

src/dependency_injector/providers.pyi

@@ -54,6 +54,8 @@ class Object(Provider, Generic[T]):
 class Delegate(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]):
@@ -122,14 +124,17 @@ class CoroutineDelegate(Delegate):
 
 class ConfigurationOption(Provider):
     UNDEFINED: object
-    def __init__(self, name: str, root: Configuration) -> None: ...
+    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: str) -> ConfigurationOption: ...
+    def __getitem__(self, item: Union[str, Provider]) -> ConfigurationOption: ...
+    @property
+    def root(self) -> Configuration: ...
     def get_name(self) -> str: ...
-    def as_int(self) -> Callable[int]: ...
-    def as_float(self) -> Callable[float]: ...
-    def as_(self, callback: _Callable[..., T], *args: Injection, **kwargs: Injection) -> Callable[T]: ...
+    def get_name_segments(self) -> Tuple[Union[str, Provider]]: ...
+    def as_int(self) -> TypedConfigurationOption[int]: ...
+    def as_float(self) -> TypedConfigurationOption[float]: ...
+    def as_(self, callback: _Callable[..., T], *args: Injection, **kwargs: Injection) -> TypedConfigurationOption[T]: ...
     def update(self, value: Any) -> None: ...
     def from_ini(self, filepath: str) -> None: ...
     def from_yaml(self, filepath: str) -> None: ...
@@ -137,11 +142,16 @@ class ConfigurationOption(Provider):
     def from_env(self, name: str, default: Optional[Any] = None) -> None: ...
 
 
+class TypedConfigurationOption(Callable[T]):
+    @property
+    def option(self) -> ConfigurationOption: ...
+
+
 class Configuration(Object):
     DEFAULT_NAME: str = 'config'
     def __init__(self, name: str = DEFAULT_NAME, default: Optional[Any] = None) -> None: ...
     def __getattr__(self, item: str) -> ConfigurationOption: ...
-    def __getitem__(self, item: str) -> ConfigurationOption: ...
+    def __getitem__(self, item: Union[str, Provider]) -> ConfigurationOption: ...
     def get_name(self) -> str: ...
     def get(self, selector: str) -> Any: ...
     def set(self, selector: str, value: Any) -> OverridingContext: ...
@@ -268,6 +278,8 @@ class Container(Provider):
     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):

src/dependency_injector/providers.pyx

@@ -8,6 +8,7 @@ import re
 import sys
 import types
 import threading
+import warnings
 import weakref
 
 try:
@@ -257,6 +258,11 @@ cdef class Provider(object):
 
         :rtype: :py:class:`Delegate`
         """
+        warnings.warn(
+            'Method ".delegate()" is deprecated since version 4.0.0. '
+            'Use ".provider" attribute instead.',
+            category=DeprecationWarning,
+        )
         return Delegate(self)
 
     @property
@@ -391,6 +397,11 @@ cdef class Delegate(Provider):
         """
         return self.__str__()
 
+    @property
+    def provides(self):
+        """Return provider."""
+        return self.__provides
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return provided instance.
 
@@ -1139,18 +1150,25 @@ cdef class ConfigurationOption(Provider):
             segment() if is_provider(segment) else segment for segment in self.__name
         )
 
+    @property
+    def root(self):
+        return self.__root_ref()
+
     def get_name(self):
         root = self.__root_ref()
         return '.'.join((root.get_name(), self._get_self_name()))
 
+    def get_name_segments(self):
+        return self.__name
+
     def as_int(self):
-        return Callable(int, self)
+        return TypedConfigurationOption(int, self)
 
     def as_float(self):
-        return Callable(float, self)
+        return TypedConfigurationOption(float, self)
 
     def as_(self, callback, *args, **kwargs):
-        return Callable(callback, self, *args, **kwargs)
+        return TypedConfigurationOption(callback, self, *args, **kwargs)
 
     def override(self, value):
         if isinstance(value, Provider):
@@ -1262,6 +1280,13 @@ cdef class ConfigurationOption(Provider):
         self.override(value)
 
 
+cdef class TypedConfigurationOption(Callable):
+
+    @property
+    def option(self):
+        return self.args[0]
+
+
 cdef class Configuration(Object):
     """Configuration provider provides configuration options to the other providers.
 
@@ -2458,13 +2483,13 @@ cdef class Container(Provider):
 
     def __init__(self, container_cls, container=None, **overriding_providers):
         """Initialize provider."""
-        self.container_cls = container_cls
-        self.overriding_providers = overriding_providers
+        self.__container_cls = container_cls
+        self.__overriding_providers = overriding_providers
 
         if container is None:
             container = container_cls()
             container.override_providers(**overriding_providers)
-        self.container = container
+        self.__container = container
 
         super(Container, self).__init__()
 
@@ -2475,9 +2500,9 @@ cdef class Container(Provider):
             return copied
 
         copied = self.__class__(
-            self.container_cls,
-            deepcopy(self.container, memo),
-            **deepcopy(self.overriding_providers, memo),
+            self.__container_cls,
+            deepcopy(self.__container, memo),
+            **deepcopy(self.__overriding_providers, memo),
         )
 
         return copied
@@ -2489,7 +2514,11 @@ cdef class Container(Provider):
                 '\'{cls}\' object has no attribute '
                 '\'{attribute_name}\''.format(cls=self.__class__.__name__,
                                               attribute_name=name))
-        return getattr(self.container, name)
+        return getattr(self.__container, name)
+
+    @property
+    def container(self):
+        return self.__container
 
     def override(self, provider):
         """Override provider with another provider."""
@@ -2497,7 +2526,7 @@ cdef class Container(Provider):
 
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return single instance."""
-        return self.container
+        return self.__container
 
 
 cdef class Selector(Provider):
@@ -2657,6 +2686,11 @@ cdef class ProvidedInstance(Provider):
     def __getitem__(self, item):
         return ItemGetter(self, item)
 
+    @property
+    def provides(self):
+        """Return provider."""
+        return self.__provider
+
     def call(self, *args, **kwargs):
         return MethodCaller(self, *args, **kwargs)
 
@@ -2696,6 +2730,16 @@ cdef class AttributeGetter(Provider):
     def __getitem__(self, item):
         return ItemGetter(self, item)
 
+    @property
+    def provides(self):
+        """Return provider."""
+        return self.__provider
+
+    @property
+    def name(self):
+        """Return name of the attribute."""
+        return self.__attribute
+
     def call(self, *args, **kwargs):
         return MethodCaller(self, *args, **kwargs)
 
@@ -2736,6 +2780,16 @@ cdef class ItemGetter(Provider):
     def __getitem__(self, item):
         return ItemGetter(self, item)
 
+    @property
+    def provides(self):
+        """Return provider."""
+        return self.__provider
+
+    @property
+    def name(self):
+        """Return name of the item."""
+        return self.__item
+
     def call(self, *args, **kwargs):
         return MethodCaller(self, *args, **kwargs)
 
@@ -2787,6 +2841,37 @@ cdef class MethodCaller(Provider):
     def __getitem__(self, item):
         return ItemGetter(self, item)
 
+    @property
+    def provides(self):
+        """Return provider."""
+        return self.__provider
+
+    @property
+    def args(self):
+        """Return positional argument injections."""
+        cdef int index
+        cdef PositionalInjection arg
+        cdef list args
+
+        args = list()
+        for index in range(self.__args_len):
+            arg = self.__args[index]
+            args.append(arg.__value)
+        return tuple(args)
+
+    @property
+    def kwargs(self):
+        """Return keyword argument injections."""
+        cdef int index
+        cdef NamedInjection kwarg
+        cdef dict kwargs
+
+        kwargs = dict()
+        for index in range(self.__kwargs_len):
+            kwarg = self.__kwargs[index]
+            kwargs[kwarg.__name] = kwarg.__value
+        return kwargs
+
     def call(self, *args, **kwargs):
         return MethodCaller(self, *args, **kwargs)
 

src/dependency_injector/types.py

@@ -1,17 +0,0 @@
-from typing import TypeVar, Generic, Any
-import warnings
-
-
-warnings.warn(
-    'Types module is deprecated since version 3.44.0. Use "providers" module instead: '
-    'providers.Provider[SomeClass]',
-    category=DeprecationWarning,
-)
-
-
-Injection = Any
-T = TypeVar('T')
-
-
-class Provider(Generic[T]):
-    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...

src/dependency_injector/wiring.py

@@ -0,0 +1,321 @@
+"""Wiring module."""
+
+import functools
+import inspect
+import pkgutil
+import sys
+from types import ModuleType
+from typing import Optional, Iterable, Callable, Any, Type, Dict, Generic, TypeVar, cast
+
+if sys.version_info < (3, 7):
+    from typing import GenericMeta
+else:
+    class GenericMeta(type):
+        ...
+
+
+from . import providers
+
+
+__all__ = (
+    'wire',
+    'unwire',
+    'Provide',
+    'Provider',
+)
+
+T = TypeVar('T')
+Container = Any
+
+
+class ProvidersMap:
+
+    def __init__(self, container):
+        self._container = container
+        self._map = self._create_providers_map(
+            current_providers=container.providers,
+            original_providers=container.declarative_parent.providers,
+        )
+
+    def resolve_provider(self, provider: providers.Provider) -> providers.Provider:
+        if isinstance(provider, providers.Delegate):
+            return self._resolve_delegate(provider)
+        elif isinstance(provider, (
+            providers.ProvidedInstance,
+            providers.AttributeGetter,
+            providers.ItemGetter,
+            providers.MethodCaller,
+        )):
+            return self._resolve_provided_instance(provider)
+        elif isinstance(provider, providers.ConfigurationOption):
+            return self._resolve_config_option(provider)
+        elif isinstance(provider, providers.TypedConfigurationOption):
+            return self._resolve_config_option(provider.option, as_=provider.provides)
+        else:
+            return self._resolve_provider(provider)
+
+    def _resolve_delegate(self, original: providers.Delegate) -> providers.Provider:
+        return self._resolve_provider(original.provides)
+
+    def _resolve_provided_instance(self, original: providers.Provider) -> providers.Provider:
+        modifiers = []
+        while isinstance(original, (
+                providers.ProvidedInstance,
+                providers.AttributeGetter,
+                providers.ItemGetter,
+                providers.MethodCaller,
+        )):
+            modifiers.insert(0, original)
+            original = original.provides
+
+        new = self._resolve_provider(original)
+
+        for modifier in modifiers:
+            if isinstance(modifier, providers.ProvidedInstance):
+                new = new.provided
+            elif isinstance(modifier, providers.AttributeGetter):
+                new = getattr(new, modifier.name)
+            elif isinstance(modifier, providers.ItemGetter):
+                new = new[modifier.name]
+            elif isinstance(modifier, providers.MethodCaller):
+                new = new.call(
+                    *modifier.args,
+                    **modifier.kwargs,
+                )
+
+        return new
+
+    def _resolve_config_option(
+            self,
+            original: providers.ConfigurationOption,
+            as_: Any = None,
+    ) -> providers.Provider:
+        original_root = original.root
+        new = self._resolve_provider(original_root)
+        new = cast(providers.Configuration, new)
+
+        for segment in original.get_name_segments():
+            if providers.is_provider(segment):
+                segment = self.resolve_provider(segment)
+                new = new[segment]
+            else:
+                new = getattr(new, segment)
+
+        if as_:
+            new = new.as_(as_)
+
+        return new
+
+    def _resolve_provider(self, original: providers.Provider) -> providers.Provider:
+        try:
+            return self._map[original]
+        except KeyError:
+            raise Exception('Unable to resolve original provider')
+
+    @classmethod
+    def _create_providers_map(
+            cls,
+            current_providers: Dict[str, providers.Provider],
+            original_providers: Dict[str, providers.Provider],
+    ) -> Dict[providers.Provider, providers.Provider]:
+        providers_map = {}
+        for provider_name, current_provider in current_providers.items():
+            original_provider = original_providers[provider_name]
+            providers_map[original_provider] = current_provider
+
+            if isinstance(current_provider, providers.Container) \
+                    and isinstance(original_provider, providers.Container):
+                subcontainer_map = cls._create_providers_map(
+                    current_providers=current_provider.container.providers,
+                    original_providers=original_provider.container.providers,
+                )
+                providers_map.update(subcontainer_map)
+
+        return providers_map
+
+
+def wire(
+        container: Container,
+        *,
+        modules: Optional[Iterable[ModuleType]] = None,
+        packages: Optional[Iterable[ModuleType]] = None,
+) -> None:
+    """Wire container providers with provided packages and modules."""
+    if not _is_declarative_container_instance(container):
+        raise Exception('Can wire only an instance of the declarative container')
+
+    if not modules:
+        modules = []
+
+    if packages:
+        for package in packages:
+            modules.extend(_fetch_modules(package))
+
+    providers_map = ProvidersMap(container)
+
+    for module in modules:
+        for name, member in inspect.getmembers(module):
+            if inspect.isfunction(member):
+                _patch_fn(module, name, member, providers_map)
+            elif inspect.isclass(member):
+                _patch_cls(member, providers_map)
+
+
+def unwire(
+        *,
+        modules: Optional[Iterable[ModuleType]] = None,
+        packages: Optional[Iterable[ModuleType]] = None,
+) -> None:
+    """Wire provided packages and modules with previous wired providers."""
+    if not modules:
+        modules = []
+
+    if packages:
+        for package in packages:
+            modules.extend(_fetch_modules(package))
+
+    for module in modules:
+        for name, member in inspect.getmembers(module):
+            if inspect.isfunction(member):
+                _unpatch_fn(module, name, member)
+            elif inspect.isclass(member):
+                _unpatch_cls(member,)
+
+
+def _patch_cls(
+        cls: Type[Any],
+        providers_map: ProvidersMap,
+) -> None:
+    if not hasattr(cls, '__init__'):
+        return
+    init_method = getattr(cls, '__init__')
+    injections = _resolve_injections(init_method, providers_map)
+    if not injections:
+        return
+    setattr(cls, '__init__', _patch_with_injections(init_method, injections))
+
+
+def _unpatch_cls(cls: Type[Any]) -> None:
+    if not hasattr(cls, '__init__'):
+        return
+    init_method = getattr(cls, '__init__')
+    if not _is_patched(init_method):
+        return
+    setattr(cls, '__init__', _get_original_from_patched(init_method))
+
+
+def _patch_fn(
+        module: ModuleType,
+        name: str,
+        fn: Callable[..., Any],
+        providers_map: ProvidersMap,
+) -> None:
+    injections = _resolve_injections(fn, providers_map)
+    if not injections:
+        return
+    setattr(module, name, _patch_with_injections(fn, injections))
+
+
+def _unpatch_fn(
+        module: ModuleType,
+        name: str,
+        fn: Callable[..., Any],
+) -> None:
+    if not _is_patched(fn):
+        return
+    setattr(module, name, _get_original_from_patched(fn))
+
+
+def _resolve_injections(fn: Callable[..., Any], providers_map: ProvidersMap) -> Dict[str, Any]:  # noqa
+    signature = inspect.signature(fn)
+
+    injections = {}
+    for parameter_name, parameter in signature.parameters.items():
+        if not isinstance(parameter.default, _Marker):
+            continue
+        marker = parameter.default
+
+        provider = providers_map.resolve_provider(marker.provider)
+        if isinstance(marker, Provide):
+            injections[parameter_name] = provider
+        elif isinstance(marker, Provider):
+            injections[parameter_name] = provider.provider
+
+    return injections
+
+
+def _fetch_modules(package):
+    modules = []
+    for loader, module_name, is_pkg in pkgutil.walk_packages(
+            path=package.__path__,
+            prefix=package.__name__ + '.',
+    ):
+        module = loader.find_module(module_name).load_module(module_name)
+        modules.append(module)
+    return modules
+
+
+def _patch_with_injections(fn, injections):
+    if inspect.iscoroutinefunction(fn):
+        @functools.wraps(fn)
+        async def _patched(*args, **kwargs):
+            to_inject = {}
+            for injection, provider in injections.items():
+                to_inject[injection] = provider()
+
+            to_inject.update(kwargs)
+
+            return await fn(*args, **to_inject)
+    else:
+        @functools.wraps(fn)
+        def _patched(*args, **kwargs):
+            to_inject = {}
+            for injection, provider in injections.items():
+                to_inject[injection] = provider()
+
+            to_inject.update(kwargs)
+
+            return fn(*args, **to_inject)
+
+    _patched.__wired__ = True
+    _patched.__original__ = fn
+    _patched.__injections__ = injections
+
+    return _patched
+
+
+def _is_patched(fn):
+    return getattr(fn, '__wired__', False) is True
+
+
+def _get_original_from_patched(fn):
+    return getattr(fn, '__original__')
+
+
+def _is_declarative_container_instance(instance: Any) -> bool:
+    return (not isinstance(instance, type)
+            and getattr(instance, '__IS_CONTAINER__', False) is True
+            and getattr(instance, 'declarative_parent', None) is not None)
+
+
+class ClassGetItemMeta(GenericMeta):
+    def __getitem__(cls, item):
+        # Spike for Python 3.6
+        return cls(item)
+
+
+class _Marker(Generic[T], metaclass=ClassGetItemMeta):
+
+    def __init__(self, provider: providers.Provider) -> None:
+        self.provider = provider
+
+    def __class_getitem__(cls, item) -> T:
+        return cls(item)
+
+
+class Provide(_Marker):
+    ...
+
+
+class Provider(_Marker):
+    ...

tests/unit/wiring/__init__.py

@@ -0,0 +1 @@
+"""Wiring tests."""

tests/unit/wiring/container.py

@@ -0,0 +1,17 @@
+from dependency_injector import containers, providers
+
+from .service import Service
+
+
+class SubContainer(containers.DeclarativeContainer):
+
+    int_object = providers.Object(1)
+
+
+class Container(containers.DeclarativeContainer):
+
+    config = providers.Configuration()
+
+    service = providers.Factory(Service)
+
+    sub = providers.Container(SubContainer)

tests/unit/wiring/module.py

@@ -0,0 +1,49 @@
+"""Test module for wiring."""
+
+from decimal import Decimal
+from typing import Callable
+
+from dependency_injector.wiring import Provide, Provider
+
+from .container import Container
+from .service import Service
+
+
+class TestClass:
+
+    def __init__(self, service: Service = Provide[Container.service]):
+        self.service = service
+
+
+def test_function(service: Service = Provide[Container.service]):
+    return service
+
+
+def test_function_provider(service_provider: Callable[..., Service] = Provider[Container.service]):
+    service = service_provider()
+    return service
+
+
+def test_config_value(
+        some_value_int: int = Provide[Container.config.a.b.c.as_int()],
+        some_value_str: str = Provide[Container.config.a.b.c.as_(str)],
+        some_value_decimal: Decimal = Provide[Container.config.a.b.c.as_(Decimal)],
+):
+    return some_value_int, some_value_str, some_value_decimal
+
+
+def test_provide_provider(service_provider: Callable[..., Service] = Provider[Container.service.provider]):
+    service = service_provider()
+    return service
+
+
+def test_provided_instance(some_value: int = Provide[Container.service.provided.foo['bar'].call()]):
+    return some_value
+
+
+def test_subcontainer_provider(some_value: int = Provide[Container.sub.int_object]):
+    return some_value
+
+
+def test_config_invariant(some_value: int = Provide[Container.config.option[Container.config.switch]]):
+    return some_value

tests/unit/wiring/package/subpackage/submodule.py

@@ -0,0 +1,8 @@
+from dependency_injector.wiring import Provide
+
+from ...container import Container
+from ...service import Service
+
+
+def test_function(service: Service = Provide[Container.service]):
+    return service

tests/unit/wiring/service.py

@@ -0,0 +1,2 @@
+class Service:
+    service_attr: int

tests/unit/wiring/test_wiring_py36.py

@@ -0,0 +1,106 @@
+from decimal import Decimal
+import unittest
+
+from dependency_injector.wiring import wire
+
+from . import module, package
+from .service import Service
+from .container import Container
+
+
+class WiringTest(unittest.TestCase):
+
+    container: Container
+
+    def setUp(self) -> None:
+        self.container = Container(config={'a': {'b': {'c': 10}}})
+        self.container.wire(
+            modules=[module],
+            packages=[package],
+        )
+        self.addCleanup(self.container.unwire)
+
+    def test_package_lookup(self):
+        from .package.subpackage.submodule import test_function
+        service = test_function()
+        self.assertIsInstance(service, Service)
+
+    def test_class_wiring(self):
+        test_class_object = module.TestClass()
+        self.assertIsInstance(test_class_object.service, Service)
+
+    def test_class_wiring_context_arg(self):
+        test_service = self.container.service()
+
+        test_class_object = module.TestClass(service=test_service)
+        self.assertIs(test_class_object.service, test_service)
+
+    def test_function_wiring(self):
+        service = module.test_function()
+        self.assertIsInstance(service, Service)
+
+    def test_function_wiring_context_arg(self):
+        test_service = self.container.service()
+
+        service = module.test_function(service=test_service)
+        self.assertIs(service, test_service)
+
+    def test_function_wiring_provider(self):
+        service = module.test_function_provider()
+        self.assertIsInstance(service, Service)
+
+    def test_function_wiring_provider_context_arg(self):
+        test_service = self.container.service()
+
+        service = module.test_function_provider(service_provider=lambda: test_service)
+        self.assertIs(service, test_service)
+
+    def test_configuration_option(self):
+        int_value, str_value, decimal_value = module.test_config_value()
+        self.assertEqual(int_value, 10)
+        self.assertEqual(str_value, '10')
+        self.assertEqual(decimal_value, Decimal(10))
+
+    def test_provide_provider(self):
+        service = module.test_provide_provider()
+        self.assertIsInstance(service, Service)
+
+    def test_provided_instance(self):
+        class TestService:
+            foo = {
+                'bar': lambda: 10,
+            }
+
+        with self.container.service.override(TestService()):
+            some_value = module.test_provided_instance()
+        self.assertEqual(some_value, 10)
+
+    def test_subcontainer(self):
+        some_value = module.test_subcontainer_provider()
+        self.assertEqual(some_value, 1)
+
+    def test_config_invariant(self):
+        config = {
+            'option': {
+                'a': 1,
+                'b': 2,
+            },
+            'switch': 'a',
+        }
+        self.container.config.from_dict(config)
+
+        with self.container.config.switch.override('a'):
+            value_a = module.test_config_invariant()
+        self.assertEqual(value_a, 1)
+
+        with self.container.config.switch.override('b'):
+            value_b = module.test_config_invariant()
+        self.assertEqual(value_b, 2)
+
+    def test_wire_with_class_error(self):
+        with self.assertRaises(Exception):
+            wire(
+                container=Container,
+                modules=[module],
+            )
+