yetone / responses

A utility for mocking out the Python Requests library.

Responses

A utility library for mocking out the requests Python library.

Note

Responses requires Requests >= 2.0

Response body as string

import responses
import requests

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

    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"}'

You can also specify a JSON object instead of a body string.

import responses
import requests

@responses.activate
def test_my_api():
    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"}'

Request callback

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'
    )

Instead of passing a string URL into responses.add or responses.add_callback you can also supply a compiled regular expression.

import re
import responses
import requests

# Instead of
responses.add(responses.GET, 'http://twitter.com/api/1/foobar',
              body='{"error": "not found"}', status=404,
              content_type='application/json')

# You can do the following
url_re = re.compile(r'https?://twitter.com/api/\d+/foobar')
responses.add(responses.GET, url_re,
              body='{"error": "not found"}', status=404,
              content_type='application/json')

A response can also throw an exception as follows.

import responses
import requests
from requests.exceptions import HTTPError

exception = HTTPError('Something went wrong')
responses.add(responses.GET, 'http://twitter.com/api/1/foobar',
              body=exception)
# All calls to 'http://twitter.com/api/1/foobar' will throw exception.

Responses as a context manager

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

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:

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')