gecko-dev/third_party/python/responses

Responses
=========

..  image:: https://travis-ci.org/getsentry/responses.svg?branch=master
    :target: https://travis-ci.org/getsentry/responses

A utility library for mocking out the `requests` Python library.

..  note::

    Responses requires Python 2.7 or newer, and requests >= 2.0


Installing
----------

``pip install responses``


Basics
------

The core of ``responses`` comes from registering mock responses:

..  code-block:: python

    import responses
    import requests

    @responses.activate
    def test_simple():
        responses.add(responses.GET, 'http://twitter.com/api/1/foobar',
                      json={'error': 'not found'}, status=404)

        resp = requests.get('http://twitter.com/api/1/foobar')

        assert resp.json() == {"error": "not found"}

        assert len(responses.calls) == 1
        assert responses.calls[0].request.url == 'http://twitter.com/api/1/foobar'
        assert responses.calls[0].response.text == '{"error": "not found"}'

If you attempt to fetch a url which doesn't hit a match, ``responses`` will raise
a ``ConnectionError``:

..  code-block:: python

    import responses
    import requests

    from requests.exceptions import ConnectionError

    @responses.activate
    def test_simple():
        with pytest.raises(ConnectionError):
            requests.get('http://twitter.com/api/1/foobar')

Lastly, you can pass an ``Exception`` as the body to trigger an error on the request:

..  code-block:: python

    import responses
    import requests

    @responses.activate
    def test_simple():
        responses.add(responses.GET, 'http://twitter.com/api/1/foobar',
                      body=Exception('...'))
        with pytest.raises(Exception):
            requests.get('http://twitter.com/api/1/foobar')


Response Parameters
-------------------

Responses are automatically registered via params on ``add``, but can also be
passed directly:

..  code-block:: python

    import responses

    responses.add(
        responses.Response(
            method='GET',
            url='http://example.com',
        )
    )

The following attributes can be passed to a Response mock:

method (``str``)
    The HTTP method (GET, POST, etc).

url (``str`` or compiled regular expression)
    The full resource URL.

match_querystring (``bool``)
    Include the query string when matching requests.
    Enabled by default if the response URL contains a query string,
    disabled if it doesn't or the URL is a regular expression.

body (``str`` or ``BufferedReader``)
    The response body.

json
    A Python object representing the JSON response body. Automatically configures
    the appropriate Content-Type.

status (``int``)
    The HTTP status code.

content_type (``content_type``)
    Defaults to ``text/plain``.

headers (``dict``)
    Response headers.

stream (``bool``)
    Disabled by default. Indicates the response should use the streaming API.


Dynamic Responses
-----------------

You can utilize callbacks to provide dynamic responses. The callback must return
a tuple of (``status``, ``headers``, ``body``).

..  code-block:: python

    import json

    import responses
    import requests

    @responses.activate
    def test_calc_api():

        def request_callback(request):
            payload = json.loads(request.body)
            resp_body = {'value': sum(payload['numbers'])}
            headers = {'request-id': '728d329e-0e86-11e4-a748-0c84dc037c13'}
            return (200, headers, json.dumps(resp_body))

        responses.add_callback(
            responses.POST, 'http://calc.com/sum',
            callback=request_callback,
            content_type='application/json',
        )

        resp = requests.post(
            'http://calc.com/sum',
            json.dumps({'numbers': [1, 2, 3]}),
            headers={'content-type': 'application/json'},
        )

        assert resp.json() == {'value': 6}

        assert len(responses.calls) == 1
        assert responses.calls[0].request.url == 'http://calc.com/sum'
        assert responses.calls[0].response.text == '{"value": 6}'
        assert (
            responses.calls[0].response.headers['request-id'] ==
            '728d329e-0e86-11e4-a748-0c84dc037c13'
        )

You can also pass a compiled regex to `add_callback` to match multiple urls:

..  code-block:: python

    import re, json

    from functools import reduce

    import responses
    import requests

    operators = {
      'sum': lambda x, y: x+y,
      'prod': lambda x, y: x*y,
      'pow': lambda x, y: x**y
    }

    @responses.activate
    def test_regex_url():

        def request_callback(request):
            payload = json.loads(request.body)
            operator_name = request.path_url[1:]

            operator = operators[operator_name]

            resp_body = {'value': reduce(operator, payload['numbers'])}
            headers = {'request-id': '728d329e-0e86-11e4-a748-0c84dc037c13'}
            return (200, headers, json.dumps(resp_body))

        responses.add_callback(
            responses.POST,
            re.compile('http://calc.com/(sum|prod|pow|unsupported)'),
            callback=request_callback,
            content_type='application/json',
        )

        resp = requests.post(
            'http://calc.com/prod',
            json.dumps({'numbers': [2, 3, 4]}),
            headers={'content-type': 'application/json'},
        )
        assert resp.json() == {'value': 24}

    test_regex_url()


If you want to pass extra keyword arguments to the callback function, for example when reusing
a callback function to give a slightly different result, you can use ``functools.partial``:

.. code-block:: python

    from functools import partial

    ...

        def request_callback(request, id=None):
            payload = json.loads(request.body)
            resp_body = {'value': sum(payload['numbers'])}
            headers = {'request-id': id}
            return (200, headers, json.dumps(resp_body))

        responses.add_callback(
            responses.POST, 'http://calc.com/sum',
            callback=partial(request_callback, id='728d329e-0e86-11e4-a748-0c84dc037c13'),
            content_type='application/json',
        )


Responses as a context manager
------------------------------

..  code-block:: python

    import responses
    import requests

    def test_my_api():
        with responses.RequestsMock() as rsps:
            rsps.add(responses.GET, 'http://twitter.com/api/1/foobar',
                     body='{}', status=200,
                     content_type='application/json')
            resp = requests.get('http://twitter.com/api/1/foobar')

            assert resp.status_code == 200

        # outside the context manager requests will hit the remote server
        resp = requests.get('http://twitter.com/api/1/foobar')
        resp.status_code == 404

Responses as a pytest fixture
-----------------------------

.. code-block:: python

    @pytest.fixture
    def mocked_responses():
        with responses.RequestsMock() as rsps:
            yield rsps

    def test_api(mocked_responses):
        mocked_responses.add(
            responses.GET, 'http://twitter.com/api/1/foobar',
            body='{}', status=200,
            content_type='application/json')
        resp = requests.get('http://twitter.com/api/1/foobar')
        assert resp.status_code == 200

Assertions on declared responses
--------------------------------

When used as a context manager, Responses will, by default, raise an assertion
error if a url was registered but not accessed. This can be disabled by passing
the ``assert_all_requests_are_fired`` value:

.. code-block:: python

    import responses
    import requests

    def test_my_api():
        with responses.RequestsMock(assert_all_requests_are_fired=False) as rsps:
            rsps.add(responses.GET, 'http://twitter.com/api/1/foobar',
                     body='{}', status=200,
                     content_type='application/json')


Multiple Responses
------------------

You can also add multiple responses for the same url:

..  code-block:: python

    import responses
    import requests

    @responses.activate
    def test_my_api():
        responses.add(responses.GET, 'http://twitter.com/api/1/foobar', status=500)
        responses.add(responses.GET, 'http://twitter.com/api/1/foobar',
                      body='{}', status=200,
                      content_type='application/json')

        resp = requests.get('http://twitter.com/api/1/foobar')
        assert resp.status_code == 500
        resp = requests.get('http://twitter.com/api/1/foobar')
        assert resp.status_code == 200


Using a callback to modify the response
---------------------------------------

If you use customized processing in `requests` via subclassing/mixins, or if you
have library tools that interact with `requests` at a low level, you may need
to add extended processing to the mocked Response object to fully simulate the
environment for your tests.  A `response_callback` can be used, which will be
wrapped by the library before being returned to the caller.  The callback
accepts a `response` as it's single argument, and is expected to return a
single `response` object.

..  code-block:: python

    import responses
    import requests

    def response_callback(resp):
        resp.callback_processed = True
        return resp

    with responses.RequestsMock(response_callback=response_callback) as m:
        m.add(responses.GET, 'http://example.com', body=b'test')
        resp = requests.get('http://example.com')
        assert resp.text == "test"
        assert hasattr(resp, 'callback_processed')
        assert resp.callback_processed is True


Passing thru real requests
--------------------------

In some cases you may wish to allow for certain requests to pass thru responses
and hit a real server. This can be done with the 'passthru' methods:

.. code-block:: python

    import responses

    @responses.activate
    def test_my_api():
        responses.add_passthru('https://percy.io')

This will allow any requests matching that prefix, that is otherwise not registered
as a mock response, to passthru using the standard behavior.


Viewing/Modifying registered responses
--------------------------------------

Registered responses are available as a private attribute of the RequestMock
instance. It is sometimes useful for debugging purposes to view the stack of
registered responses which can be accessed via ``responses.mock._matches``.

The ``replace`` function allows a previously registered ``response`` to be
changed. The method signature is identical to ``add``. ``response``s are
identified using ``method`` and ``url``. Only the first matched ``response`` is
replaced.

..  code-block:: python

    import responses
    import requests

    @responses.activate
    def test_replace():

        responses.add(responses.GET, 'http://example.org', json={'data': 1})
        responses.replace(responses.GET, 'http://example.org', json={'data': 2})

        resp = requests.get('http://example.org')

        assert resp.json() == {'data': 2}


``remove`` takes a ``method`` and ``url`` argument and will remove *all*
matched ``response``s from the registered list.

Finally, ``clear`` will reset all registered ``response``s



Contributing
------------

Responses uses several linting and autoformatting utilities, so it's important that when
submitting patches you use the appropriate toolchain:

Clone the repository:

.. code-block:: shell

    git clone https://github.com/getsentry/responses.git

Create an environment (e.g. with ``virtualenv``):

.. code-block:: shell

    virtualenv .env && source .env/bin/activate

Configure development requirements:

.. code-block:: shell

    make develop