mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2025-11-04 01:47:36 +03:00
864 lines
22 KiB
ReStructuredText
864 lines
22 KiB
ReStructuredText
.. _aiohttp-tutorial:
|
||
|
||
Aiohttp tutorial
|
||
================
|
||
|
||
.. meta::
|
||
:keywords: Python,Aiohttp,Tutorial,Education,Web,API,REST API,Example,DI,Dependency injection,
|
||
IoC,Inversion of control,Refactoring,Tests,Unit tests,Pytest,py.test,Bootstrap,
|
||
HTML,CSS
|
||
:description: This tutorial shows how to build an aiohttp application following the dependency
|
||
injection principle. You will create the REST API application, connect to the
|
||
Giphy API, cover it with the unit test and make some refactoring.
|
||
|
||
This tutorial shows how to build an ``aiohttp`` REST API application following the dependency
|
||
injection principle.
|
||
|
||
Start from the scratch or jump to the section:
|
||
|
||
.. contents::
|
||
:local:
|
||
:backlinks: none
|
||
|
||
You can find complete project on the
|
||
`Github <https://github.com/ets-labs/python-dependency-injector/tree/master/examples/miniapps/aiohttp>`_.
|
||
|
||
What are we going to build?
|
||
---------------------------
|
||
|
||
.. image:: https://media.giphy.com/media/apvx5lPCPsjN6/source.gif
|
||
|
||
We will build a REST API application that searches for funny GIFs on the `Giphy <https://giphy.com/>`_.
|
||
Let's call it Giphy Navigator.
|
||
|
||
How does Giphy Navigator work?
|
||
|
||
- Client sends a request specifying the search query and the number of results.
|
||
- Giphy Navigator returns a response in json format.
|
||
- The response contains:
|
||
- the search query
|
||
- the limit number
|
||
- the list of gif urls
|
||
|
||
Example response:
|
||
|
||
.. 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"
|
||
}
|
||
]
|
||
}
|
||
|
||
The task is naive and that's exactly what we need for the tutorial.
|
||
|
||
Prepare the environment
|
||
-----------------------
|
||
|
||
Let's create the environment for the project.
|
||
|
||
First we need to create a project folder:
|
||
|
||
.. code-block:: bash
|
||
|
||
mkdir giphynav-aiohttp-tutorial
|
||
cd giphynav-aiohttp-tutorial
|
||
|
||
Now let's create and activate virtual environment:
|
||
|
||
.. code-block:: bash
|
||
|
||
python3 -m venv venv
|
||
. venv/bin/activate
|
||
|
||
Environment is ready and now we're going to create the layout of the project.
|
||
|
||
Project layout
|
||
--------------
|
||
|
||
Create next structure in the current directory. All files should be empty. That's ok for now.
|
||
|
||
Initial project layout::
|
||
|
||
./
|
||
├── giphynavigator/
|
||
│ ├── __init__.py
|
||
│ ├── application.py
|
||
│ ├── containers.py
|
||
│ └── handlers.py
|
||
├── venv/
|
||
└── requirements.txt
|
||
|
||
Install the requirements
|
||
------------------------
|
||
|
||
Now it's time to install the project requirements. We will use next packages:
|
||
|
||
- ``dependency-injector`` - the dependency injection framework
|
||
- ``aiohttp`` - the web framework
|
||
- ``aiohttp-devtools`` - the helper library that will provide a development server with live
|
||
reloading
|
||
- ``pyyaml`` - the YAML files parsing library, used for the reading of the configuration files
|
||
- ``pytest-aiohttp`` - the helper library for the testing of the ``aiohttp`` application
|
||
- ``pytest-cov`` - the helper library for measuring the test coverage
|
||
|
||
Put next lines into the ``requirements.txt`` file:
|
||
|
||
.. code-block:: bash
|
||
|
||
dependency-injector
|
||
aiohttp
|
||
aiohttp-devtools
|
||
pyyaml
|
||
pytest-aiohttp
|
||
pytest-cov
|
||
|
||
and run next in the terminal:
|
||
|
||
.. code-block:: bash
|
||
|
||
pip install -r requirements.txt
|
||
|
||
Let's also install the ``httpie``. It is a user-friendly command-line HTTP client for the API era.
|
||
We will use it for the manual testing.
|
||
|
||
Run the command in the terminal:
|
||
|
||
.. code-block:: bash
|
||
|
||
pip install httpie
|
||
|
||
The requirements are setup. Now we will build a minimal application.
|
||
|
||
Minimal application
|
||
-------------------
|
||
|
||
In this section we will build a minimal application. It will have an endpoint that
|
||
will answer our requests in json format. There will be no payload for now.
|
||
|
||
Edit ``handlers.py``:
|
||
|
||
.. code-block:: python
|
||
|
||
"""Handlers module."""
|
||
|
||
from aiohttp import web
|
||
|
||
|
||
async def index(request: web.Request) -> web.Response:
|
||
query = request.query.get('query', 'Dependency Injector')
|
||
limit = int(request.query.get('limit', 10))
|
||
|
||
gifs = []
|
||
|
||
return web.json_response(
|
||
{
|
||
'query': query,
|
||
'limit': limit,
|
||
'gifs': gifs,
|
||
},
|
||
)
|
||
|
||
Now let's create a container. Container will keep all of the application components and their dependencies.
|
||
|
||
Edit ``containers.py``:
|
||
|
||
.. code-block:: python
|
||
|
||
"""Containers module."""
|
||
|
||
from dependency_injector import containers
|
||
|
||
|
||
class Container(containers.DeclarativeContainer):
|
||
...
|
||
|
||
Container is empty for now. We will add the providers in the following sections.
|
||
|
||
Finally we need to create ``aiohttp`` application factory. It will create and configure container
|
||
and ``web.Application``. It is traditionally called ``create_app()``.
|
||
We will assign ``index`` handler to handle user requests to the root ``/`` of our web application.
|
||
|
||
Put next into the ``application.py``:
|
||
|
||
.. code-block:: python
|
||
|
||
"""Application module."""
|
||
|
||
from aiohttp import web
|
||
|
||
from .containers import Container
|
||
from . import handlers
|
||
|
||
|
||
def create_app() -> web.Application:
|
||
container = Container()
|
||
|
||
app = web.Application()
|
||
app.container = container
|
||
app.add_routes([
|
||
web.get('/', handlers.index),
|
||
])
|
||
return app
|
||
|
||
Now we're ready to run our application
|
||
|
||
Do next in the terminal:
|
||
|
||
.. code-block:: bash
|
||
|
||
adev runserver giphynavigator/application.py --livereload
|
||
|
||
The output should be something like:
|
||
|
||
.. code-block:: bash
|
||
|
||
[18:52:59] Starting aux server at http://localhost:8001 ◆
|
||
[18:52:59] Starting dev server at http://localhost:8000 ●
|
||
|
||
Let's check that it works. Open another terminal session and use ``httpie``:
|
||
|
||
.. code-block:: bash
|
||
|
||
http http://127.0.0.1:8000/
|
||
|
||
You should see:
|
||
|
||
.. code-block:: json
|
||
|
||
HTTP/1.1 200 OK
|
||
Content-Length: 844
|
||
Content-Type: application/json; charset=utf-8
|
||
Date: Wed, 29 Jul 2020 21:01:50 GMT
|
||
Server: Python/3.8 aiohttp/3.6.2
|
||
|
||
{
|
||
"gifs": [],
|
||
"limit": 10,
|
||
"query": "Dependency Injector"
|
||
}
|
||
|
||
Minimal application is ready. Let's connect our application with the Giphy API.
|
||
|
||
Giphy API client
|
||
----------------
|
||
|
||
In this section we will integrate our application with the Giphy API.
|
||
|
||
We will create our own API client using ``aiohttp`` client.
|
||
|
||
Create ``giphy.py`` module in the ``giphynavigator`` package:
|
||
|
||
.. code-block:: bash
|
||
:emphasize-lines: 6
|
||
|
||
./
|
||
├── giphynavigator/
|
||
│ ├── __init__.py
|
||
│ ├── application.py
|
||
│ ├── containers.py
|
||
│ ├── giphy.py
|
||
│ └── handlers.py
|
||
├── venv/
|
||
└── requirements.txt
|
||
|
||
and put next into it:
|
||
|
||
.. code-block:: python
|
||
|
||
"""Giphy client module."""
|
||
|
||
from aiohttp import ClientSession, ClientTimeout
|
||
|
||
|
||
class GiphyClient:
|
||
|
||
API_URL = 'https://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()
|
||
|
||
Now we need to add ``GiphyClient`` into the container. The ``GiphyClient`` has two dependencies
|
||
that have to be injected: the API key and the request timeout. We will need to use two more
|
||
providers from the ``dependency_injector.providers`` module:
|
||
|
||
- ``Factory`` provider that will create the ``GiphyClient`` client.
|
||
- ``Configuration`` provider that will provide the API key and the request timeout.
|
||
|
||
Edit ``containers.py``:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 3-5,10-16
|
||
|
||
"""Containers module."""
|
||
|
||
from dependency_injector import containers, providers
|
||
|
||
from . import giphy
|
||
|
||
|
||
class Container(containers.DeclarativeContainer):
|
||
|
||
config = providers.Configuration()
|
||
|
||
giphy_client = providers.Factory(
|
||
giphy.GiphyClient,
|
||
api_key=config.giphy.api_key,
|
||
timeout=config.giphy.request_timeout,
|
||
)
|
||
|
||
.. note::
|
||
|
||
We have used the configuration value before it was defined. That's the principle how the
|
||
``Configuration`` provider works.
|
||
|
||
Use first, define later.
|
||
|
||
Now let's add the configuration file.
|
||
|
||
We will use YAML.
|
||
|
||
Create an empty file ``config.yml`` in the root root of the project:
|
||
|
||
.. code-block:: bash
|
||
:emphasize-lines: 9
|
||
|
||
./
|
||
├── giphynavigator/
|
||
│ ├── __init__.py
|
||
│ ├── application.py
|
||
│ ├── containers.py
|
||
│ ├── giphy.py
|
||
│ └── handlers.py
|
||
├── venv/
|
||
├── config.yml
|
||
└── requirements.txt
|
||
|
||
and put next into it:
|
||
|
||
.. code-block:: yaml
|
||
|
||
giphy:
|
||
request_timeout: 10
|
||
|
||
We will use an environment variable ``GIPHY_API_KEY`` to provide the API key.
|
||
|
||
Now we need to edit ``create_app()`` to make two things when application starts:
|
||
|
||
- Load the configuration file the ``config.yml``.
|
||
- Load the API key from the ``GIPHY_API_KEY`` environment variable.
|
||
|
||
Edit ``application.py``:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 11-12
|
||
|
||
"""Application module."""
|
||
|
||
from aiohttp import web
|
||
|
||
from .containers import Container
|
||
from . import handlers
|
||
|
||
|
||
def create_app() -> web.Application:
|
||
container = Container()
|
||
container.config.from_yaml('config.yml')
|
||
container.config.giphy.api_key.from_env('GIPHY_API_KEY')
|
||
|
||
app = web.Application()
|
||
app.container = container
|
||
app.add_routes([
|
||
web.get('/', handlers.index),
|
||
])
|
||
return app
|
||
|
||
|
||
Now we need to create an API key and set it to the environment variable.
|
||
|
||
As for now, don’t worry, just take this one:
|
||
|
||
.. code-block:: bash
|
||
|
||
export GIPHY_API_KEY=wBJ2wZG7SRqfrU9nPgPiWvORmloDyuL0
|
||
|
||
.. 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>`_.
|
||
|
||
The Giphy API client and the configuration setup is done. Let's proceed to the search service.
|
||
|
||
Search service
|
||
--------------
|
||
|
||
Now it's time to add the ``SearchService``. It will:
|
||
|
||
- Perform the search.
|
||
- Format result data.
|
||
|
||
``SearchService`` will use ``GiphyClient``.
|
||
|
||
Create ``services.py`` module in the ``giphynavigator`` package:
|
||
|
||
.. code-block:: bash
|
||
:emphasize-lines: 8
|
||
|
||
./
|
||
├── giphynavigator/
|
||
│ ├── __init__.py
|
||
│ ├── application.py
|
||
│ ├── containers.py
|
||
│ ├── giphy.py
|
||
│ ├── handlers.py
|
||
│ └── services.py
|
||
├── venv/
|
||
├── config.yml
|
||
└── requirements.txt
|
||
|
||
and put next into it:
|
||
|
||
.. code-block:: python
|
||
|
||
"""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']]
|
||
|
||
The ``SearchService`` has a dependency on the ``GiphyClient``. This dependency will be
|
||
injected when we add ``SearchService`` to the container.
|
||
|
||
Edit ``containers.py``:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 5,18-21
|
||
|
||
"""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,
|
||
)
|
||
|
||
The search service is ready. In next section we're going to put it to work.
|
||
|
||
Make the search work
|
||
--------------------
|
||
|
||
Now we are ready to put the search into work. Let's inject ``SearchService`` into
|
||
the ``index`` handler. We will use :ref:`wiring` feature.
|
||
|
||
Edit ``handlers.py``:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 4-7,10-13,17
|
||
|
||
"""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 = Provide[Container.search_service],
|
||
) -> web.Response:
|
||
query = request.query.get('query', 'Dependency Injector')
|
||
limit = int(request.query.get('limit', 10))
|
||
|
||
gifs = await search_service.search(query, limit)
|
||
|
||
return web.json_response(
|
||
{
|
||
'query': query,
|
||
'limit': limit,
|
||
'gifs': gifs,
|
||
},
|
||
)
|
||
|
||
To make the injection work we need to wire the container instance with the ``handlers`` module.
|
||
This needs to be done once. After it's done we can use ``Provide`` markers to specify as many
|
||
injections as needed for any handler.
|
||
|
||
Edit ``application.py``:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 13
|
||
|
||
"""Application module."""
|
||
|
||
from aiohttp import web
|
||
|
||
from .containers import Container
|
||
from . import handlers
|
||
|
||
|
||
def create_app() -> web.Application:
|
||
container = Container()
|
||
container.config.from_yaml('config.yml')
|
||
container.config.giphy.api_key.from_env('GIPHY_API_KEY')
|
||
container.wire(modules=[handlers])
|
||
|
||
app = web.Application()
|
||
app.container = container
|
||
app.add_routes([
|
||
web.get('/', handlers.index),
|
||
])
|
||
return app
|
||
|
||
Make sure the app is running or use:
|
||
|
||
.. code-block:: bash
|
||
|
||
adev runserver giphynavigator/application.py --livereload
|
||
|
||
and make a request to the API in the terminal:
|
||
|
||
.. code-block:: bash
|
||
|
||
http http://localhost:8000/ query=="wow,it works" limit==5
|
||
|
||
You should see:
|
||
|
||
.. code-block:: json
|
||
|
||
HTTP/1.1 200 OK
|
||
Content-Length: 492
|
||
Content-Type: application/json; charset=utf-8
|
||
Date: Fri, 09 Oct 2020 01:35:48 GMT
|
||
Server: Python/3.8 aiohttp/3.6.2
|
||
|
||
{
|
||
"gifs": [
|
||
{
|
||
"url": "https://giphy.com/gifs/dollyparton-3xIVVMnZfG3KQ9v4Ye"
|
||
},
|
||
{
|
||
"url": "https://giphy.com/gifs/tennistv-unbelievable-disbelief-cant-believe-UWWJnhHHbpGvZOapEh"
|
||
},
|
||
{
|
||
"url": "https://giphy.com/gifs/discoverychannel-nugget-gold-rush-rick-ness-KGGPIlnC4hr4u2s3pY"
|
||
},
|
||
{
|
||
"url": "https://giphy.com/gifs/soulpancake-wow-work-xUe4HVXTPi0wQ2OAJC"
|
||
},
|
||
{
|
||
"url": "https://giphy.com/gifs/readingrainbow-teamwork-levar-burton-reading-rainbow-3o7qE1EaTWLQGDSabK"
|
||
}
|
||
],
|
||
"limit": 5,
|
||
"query": "wow,it works"
|
||
}
|
||
|
||
.. image:: https://media.giphy.com/media/3oxHQCI8tKXoeW4IBq/source.gif
|
||
|
||
The search works!
|
||
|
||
Make some refactoring
|
||
---------------------
|
||
|
||
Our ``index`` handler has two hardcoded config values:
|
||
|
||
- Default search query
|
||
- Default results limit
|
||
|
||
Let's make some refactoring. We will move these values to the config.
|
||
|
||
Edit ``handlers.py``:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 13-14,16-17
|
||
|
||
"""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 = 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))
|
||
|
||
gifs = await search_service.search(query, limit)
|
||
|
||
return web.json_response(
|
||
{
|
||
'query': query,
|
||
'limit': limit,
|
||
'gifs': gifs,
|
||
},
|
||
)
|
||
|
||
Let's update the config.
|
||
|
||
Edit ``config.yml``:
|
||
|
||
.. code-block:: yaml
|
||
:emphasize-lines: 3-5
|
||
|
||
giphy:
|
||
request_timeout: 10
|
||
default:
|
||
query: "Dependency Injector"
|
||
limit: 10
|
||
|
||
The refactoring is done. We've made it cleaner - hardcoded values are now moved to the config.
|
||
|
||
Tests
|
||
-----
|
||
|
||
In this section we will add some tests.
|
||
|
||
Create ``tests.py`` module in the ``giphynavigator`` package:
|
||
|
||
.. code-block:: bash
|
||
:emphasize-lines: 9
|
||
|
||
./
|
||
├── giphynavigator/
|
||
│ ├── __init__.py
|
||
│ ├── application.py
|
||
│ ├── containers.py
|
||
│ ├── giphy.py
|
||
│ ├── handlers.py
|
||
│ ├── services.py
|
||
│ └── tests.py
|
||
├── venv/
|
||
├── config.yml
|
||
└── requirements.txt
|
||
|
||
and put next into it:
|
||
|
||
.. code-block:: python
|
||
:emphasize-lines: 32,59,73
|
||
|
||
"""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()
|
||
|
||
|
||
@pytest.fixture
|
||
def client(app, aiohttp_client, loop):
|
||
return loop.run_until_complete(aiohttp_client(app))
|
||
|
||
|
||
async def test_index(client, 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 client.get(
|
||
'/',
|
||
params={
|
||
'query': 'test',
|
||
'limit': 10,
|
||
},
|
||
)
|
||
|
||
assert response.status == 200
|
||
data = await 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(client, 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 client.get('/')
|
||
|
||
assert response.status == 200
|
||
data = await response.json()
|
||
assert data['gifs'] == []
|
||
|
||
|
||
async def test_index_default_params(client, 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 client.get('/')
|
||
|
||
assert response.status == 200
|
||
data = await response.json()
|
||
assert data['query'] == app.container.config.default.query()
|
||
assert data['limit'] == app.container.config.default.limit()
|
||
|
||
Now let's run it and check the coverage:
|
||
|
||
.. code-block:: bash
|
||
|
||
py.test giphynavigator/tests.py --cov=giphynavigator
|
||
|
||
You should see:
|
||
|
||
.. 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, aiohttp-0.3.0, asyncio-0.14.0
|
||
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/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 37 0 100%
|
||
---------------------------------------------------
|
||
TOTAL 87 10 89%
|
||
|
||
.. note::
|
||
|
||
Take a look at the highlights in the ``tests.py``.
|
||
|
||
It emphasizes the overriding of the ``GiphyClient``. The real API call are mocked.
|
||
|
||
Conclusion
|
||
----------
|
||
|
||
In this tutorial we've built an ``aiohttp`` REST API application following the dependency
|
||
injection principle.
|
||
We've used the ``Dependency Injector`` as a dependency injection framework.
|
||
|
||
:ref:`containers` and :ref:`providers` helped to specify how to assemble search service and
|
||
giphy client.
|
||
|
||
:ref:`configuration-provider` helped to deal with reading YAML file and environment variable.
|
||
|
||
We used :ref:`wiring` feature to inject the dependencies into the ``index()`` handler.
|
||
:ref:`provider-overriding` feature helped in testing.
|
||
|
||
We kept all the dependencies injected explicitly. This will help when you need to add or
|
||
change something in future.
|
||
|
||
You can find complete project on the
|
||
`Github <https://github.com/ets-labs/python-dependency-injector/tree/master/examples/miniapps/aiohttp>`_.
|
||
|
||
What's next?
|
||
|
||
- Look at the other :ref:`tutorials`
|
||
- Know more about the :ref:`providers`
|
||
- Go to the :ref:`contents`
|
||
|
||
.. disqus::
|