A utility library for mocking out the requests
Python library.
Note
Responses requires Python 2.7 or newer, and requests >= 2.0
pip install responses
The core of responses
comes from registering mock responses:
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
:
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:
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')
Responses are automatically registered via params on add
, but can also be
passed directly:
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
orBufferedReader
) - 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
) - DEPRECATED: use
stream
argument in request directly - auto_calculate_content_length (
bool
) - Disabled by default. Automatically calculates the length of a supplied string or JSON body.
- match (
list
) A list of callbacks to match requests based on request attributes. Current module provides multiple matchers that you can use to match:
- body contents in JSON format
- body contents in URL encoded data format
- request query parameters
- request query string (similar to query parameters but takes string as input)
- kwargs provided to request e.g.
stream
,verify
- 'multipart/form-data' content and headers in request
- request headers
- request fragment identifier
Alternatively user can create custom matcher. Read more Matching Requests
When adding responses for endpoints that are sent request data you can add matchers to ensure your code is sending the right parameters and provide different responses based on the request body contents. Responses provides matchers for JSON and URL-encoded request bodies and you can supply your own for other formats.
import responses
import requests
from responses import matchers
@responses.activate
def test_calc_api():
responses.add(
responses.POST,
url='http://calc.com/sum',
body="4",
match=[
matchers.urlencoded_params_matcher({"left": "1", "right": "3"})
]
)
requests.post("http://calc.com/sum", data={"left": 1, "right": 3})
Matching JSON encoded data can be done with matchers.json_params_matcher()
.
If your application uses other encodings you can build your own matcher that
returns True
or False
if the request parameters match. Your matcher can
expect a request
parameter to be provided by responses.
Similarly, you can use the matchers.query_param_matcher
function to match
against the params
request parameter.
Note, you must set match_querystring=False
import responses
import requests
from responses import matchers
@responses.activate
def test_calc_api():
url = "http://example.com/test"
params = {"hello": "world", "I am": "a big test"}
responses.add(
method=responses.GET,
url=url,
body="test",
match=[matchers.query_param_matcher(params)],
match_querystring=False,
)
resp = requests.get(url, params=params)
constructed_url = r"http://example.com/test?I+am=a+big+test&hello=world"
assert resp.url == constructed_url
assert resp.request.url == constructed_url
assert resp.request.params == params
As alternative, you can use query string value in matchers.query_string_matcher
import requests
import responses
from responses import matchers
@responses.activate
def my_func():
responses.add(
responses.GET,
"https://httpbin.org/get",
match=[matchers.query_string_matcher("didi=pro&test=1")],
)
resp = requests.get("https://httpbin.org/get", params={"test": 1, "didi": "pro"})
my_func()
To validate request arguments use the matchers.request_kwargs_matcher
function to match
against the request kwargs.
Note, only arguments provided to matchers.request_kwargs_matcher
will be validated
import responses
import requests
from responses import matchers
with responses.RequestsMock(assert_all_requests_are_fired=False) as rsps:
req_kwargs = {
"stream": True,
"verify": False,
}
rsps.add(
"GET",
"http://111.com",
match=[matchers.request_kwargs_matcher(req_kwargs)],
)
requests.get("http://111.com", stream=True)
# >>> Arguments don't match: {stream: True, verify: True} doesn't match {stream: True, verify: False}
To validate request body and headers for multipart/form-data
data you can use
matchers.multipart_matcher
. The data
, and files
parameters provided will be compared
to the request:
import requests
import responses
from responses.matchers import multipart_matcher
@responses.activate
def my_func():
req_data = {"some": "other", "data": "fields"}
req_files = {"file_name": b"Old World!"}
responses.add(
responses.POST, url="http://httpbin.org/post",
match=[multipart_matcher(req_data, req_files)]
)
resp = requests.post("http://httpbin.org/post", files={"file_name": b"New World!"})
my_func()
# >>> raises ConnectionError: multipart/form-data doesn't match. Request body differs.
To validate request URL fragment identifier you can use matchers.fragment_identifier_matcher
.
The matcher takes fragment string (everything after #
sign) as input for comparison:
import requests
import responses
from responses.matchers import fragment_identifier_matcher
@responses.activate
def run():
url = "http://example.com?ab=xy&zed=qwe#test=1&foo=bar"
responses.add(
responses.GET,
url,
match_querystring=True,
match=[fragment_identifier_matcher("test=1&foo=bar")],
body=b"test",
)
# two requests to check reversed order of fragment identifier
resp = requests.get("http://example.com?ab=xy&zed=qwe#test=1&foo=bar")
resp = requests.get("http://example.com?zed=qwe&ab=xy#foo=bar&test=1")
run()
When adding responses you can specify matchers to ensure that your code is sending the right headers and provide different responses based on the request headers.
import responses
import requests
from responses import matchers
@responses.activate
def test_content_type():
responses.add(
responses.GET,
url="http://example.com/",
body="hello world",
match=[
matchers.header_matcher({"Accept": "text/plain"})
]
)
responses.add(
responses.GET,
url="http://example.com/",
json={"content": "hello world"},
match=[
matchers.header_matcher({"Accept": "application/json"})
]
)
# request in reverse order to how they were added!
resp = requests.get("http://example.com/", headers={"Accept": "application/json"})
assert resp.json() == {"content": "hello world"}
resp = requests.get("http://example.com/", headers={"Accept": "text/plain"})
assert resp.text == "hello world"
Because requests
will send several standard headers in addition to what was
specified by your code, request headers that are additional to the ones
passed to the matcher are ignored by default. You can change this behaviour by
passing strict_match=True
to the matcher to ensure that only the headers
that you're expecting are sent and no others. Note that you will probably have
to use a PreparedRequest
in your code to ensure that requests
doesn't
include any additional headers.
import responses
import requests
from responses import matchers
@responses.activate
def test_content_type():
responses.add(
responses.GET,
url="http://example.com/",
body="hello world",
match=[
matchers.header_matcher({"Accept": "text/plain"}, strict_match=True)
]
)
# this will fail because requests adds its own headers
with pytest.raises(ConnectionError):
requests.get("http://example.com/", headers={"Accept": "text/plain"})
# a prepared request where you overwrite the headers before sending will work
session = requests.Session()
prepped = session.prepare_request(
requests.Request(
method="GET",
url="http://example.com/",
)
)
prepped.headers = {"Accept": "text/plain"}
resp = session.send(prepped)
assert resp.text == "hello world"
You can utilize callbacks to provide dynamic responses. The callback must return
a tuple of (status
, headers
, body
).
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:
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
:
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',
)
You can see params passed in the original request
in responses.calls[].request.params
:
import responses
import requests
@responses.activate
def test_request_params():
responses.add(
method=responses.GET,
url="http://example.com?hello=world",
body="test",
match_querystring=False,
)
resp = requests.get('http://example.com', params={"hello": "world"})
assert responses.calls[0].request.params == {"hello": "world"}
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
@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
When run with unittest tests, this can be used to set up some generic class-level responses, that may be complemented by each test
def setUp():
self.responses = responses.RequestsMock()
self.responses.start()
# self.responses.add(...)
self.addCleanup(self.responses.stop)
self.addCleanup(self.responses.reset)
def test_api(self):
self.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
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')
Assert that the request was called exactly n times.
import responses
import requests
@responses.activate
def test_assert_call_count():
responses.add(responses.GET, "http://example.com")
requests.get("http://example.com")
assert responses.assert_call_count("http://example.com", 1) is True
requests.get("http://example.com")
with pytest.raises(AssertionError) as excinfo:
responses.assert_call_count("http://example.com", 1)
assert "Expected URL 'http://example.com' to be called 1 times. Called 2 times." in str(excinfo.value)
You can also add multiple responses for the same url:
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
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.
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
In some cases you may wish to allow for certain requests to pass through responses
and hit a real server. This can be done with the add_passthru
methods:
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.
Pass through endpoints can be configured with regex patterns if you need to allow an entire domain or path subtree to send requests:
responses.add_passthru(re.compile('https://percy.io/\\w+'))
Lastly, you can use the response.passthrough attribute on BaseResponse or
use PassthroughResponse
to enable a response to behave as a pass through.
# Enable passthrough for a single response
response = Response(responses.GET, 'http://example.com', body='not used')
response.passthrough = True
responses.add(response)
# Use PassthroughResponse
response = PassthroughResponse(responses.GET, 'http://example.com')
responses.add(response)
Registered responses are available as a public method of the RequestMock
instance. It is sometimes useful for debugging purposes to view the stack of
registered responses which can be accessed via responses.registered()
.
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.
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}
The upsert
function allows a previously registered response
to be
changed like replace
. If the response is registered, the upsert
function
will registered it like add
.
remove
takes a method
and url
argument and will remove all
matched responses from the registered list.
Finally, reset
will reset all registered responses.
Responses uses several linting and autoformatting utilities, so it's important that when submitting patches you use the appropriate toolchain:
Clone the repository:
git clone https://github.com/getsentry/responses.git
Create an environment (e.g. with virtualenv
):
virtualenv .env && source .env/bin/activate
Configure development requirements:
make develop
Responses uses Pytest for testing. You can run all tests by:
pytest
And run a single test by:
pytest -k '<test_function_name>'
To verify type
compliance, run mypy linter:
mypy --config-file=./mypy.ini -p responses
To check code style and reformat it run:
pre-commit run --all-files
Note: on some OS, you have to use pre_commit