Testing

Sanic endpoints can be tested locally using the test_client object, which depends on the additional aiohttp library.

The test_client exposes get, post, put, delete, patch, head and options methods for you to run against your application. A simple example (using pytest) is like follows:

# Import the Sanic app, usually created with Sanic(__name__)
from external_server import app

def test_index_returns_200():
    request, response = app.test_client.get('/')
    assert response.status == 200

def test_index_put_not_allowed():
    request, response = app.test_client.put('/')
    assert response.status == 405

Internally, each time you call one of the test_client methods, the Sanic app is run at 127.0.0.1:42101 and your test request is executed against your application, using aiohttp.

The test_client methods accept the following arguments and keyword arguments:

  • uri (default '/') A string representing the URI to test.
  • gather_request (default True) A boolean which determines whether the original request will be returned by the function. If set to True, the return value is a tuple of (request, response), if False only the response is returned.
  • server_kwargs *(default {}) a dict of additional arguments to pass into app.run before the test request is run.
  • debug (default False) A boolean which determines whether to run the server in debug mode.

The function further takes the *request_args and **request_kwargs, which are passed directly to the aiohttp ClientSession request.

For example, to supply data to a GET request, you would do the following:

def test_get_request_includes_data():
    params = {'key1': 'value1', 'key2': 'value2'}
    request, response = app.test_client.get('/', params=params)
    assert request.args.get('key1') == 'value1'

And to supply data to a JSON POST request:

def test_post_json_request_includes_data():
    data = {'key1': 'value1', 'key2': 'value2'}
    request, response = app.test_client.post('/', data=json.dumps(data))
    assert request.json.get('key1') == 'value1'

More information about the available arguments to aiohttp can be found in the documentation for ClientSession.

Using a random port

If you need to test using a free unpriveleged port chosen by the kernel instead of the default with SanicTestClient, you can do so by specifying port=None. On most systems the port will be in the range 1024 to 65535.

# Import the Sanic app, usually created with Sanic(__name__)
from external_server import app
from sanic.testing import SanicTestClient

def test_index_returns_200():
    request, response = SanicTestClient(app, port=None).get('/')
    assert response.status == 200

pytest-sanic

pytest-sanic is a pytest plugin, it helps you to test your code asynchronously. Just write tests like,

async def test_sanic_db_find_by_id(app):
    """
    Let's assume that, in db we have,
        {
            "id": "123",
            "name": "Kobe Bryant",
            "team": "Lakers",
        }
    """
    doc = await app.db["players"].find_by_id("123")
    assert doc.name == "Kobe Bryant"
    assert doc.team == "Lakers"

pytest-sanic also provides some useful fixtures, like loop, unused_port, test_server, test_client.

@pytest.yield_fixture
def app():
    app = Sanic("test_sanic_app")

    @app.route("/test_get", methods=['GET'])
    async def test_get(request):
        return response.json({"GET": True})

    @app.route("/test_post", methods=['POST'])
    async def test_post(request):
        return response.json({"POST": True})

    yield app


@pytest.fixture
def test_cli(loop, app, test_client):
    return loop.run_until_complete(test_client(app, protocol=WebSocketProtocol))


#########
# Tests #
#########

async def test_fixture_test_client_get(test_cli):
    """
    GET request
    """
    resp = await test_cli.get('/test_get')
    assert resp.status == 200
    resp_json = await resp.json()
    assert resp_json == {"GET": True}

async def test_fixture_test_client_post(test_cli):
    """
    POST request
    """
    resp = await test_cli.post('/test_post')
    assert resp.status == 200
    resp_json = await resp.json()
    assert resp_json == {"POST": True}