pytest_httpserver

HTTP server for pytest

Nutshell

This library is designed to help to test http clients without contacting the real http server. In other words, it is a fake http server which is accessible via localhost can be started with the pre-defined expected http requests and their responses.

Example

Handling a simple GET request

def test_my_client(
    httpserver,
):  # httpserver is a pytest fixture which starts the server
    # set up the server to serve /foobar with the json
    httpserver.expect_request("/foobar").respond_with_json({"foo": "bar"})
    # check that the request is served
    assert requests.get(httpserver.url_for("/foobar")).json() == {"foo": "bar"}

Handing a POST request with an expected json body

def test_json_request(
    httpserver,
):  # httpserver is a pytest fixture which starts the server
    # set up the server to serve /foobar with the json
    httpserver.expect_request(
        "/foobar", method="POST", json={"id": 12, "name": "foo"}
    ).respond_with_json({"foo": "bar"})
    # check that the request is served
    assert requests.post(
        httpserver.url_for("/foobar"), json={"id": 12, "name": "foo"}
    ).json() == {"foo": "bar"}

You can also use the library without pytest. There's a with statement to ensure that the server is stopped.

with HTTPServer() as httpserver:
    # set up the server to serve /foobar with the json
    httpserver.expect_request("/foobar").respond_with_json({"foo": "bar"})
    # check that the request is served
    print(requests.get(httpserver.url_for("/foobar")).json())

Documentation

Please find the API documentation at https://pytest-httpserver.readthedocs.io/en/latest/.

Features

You can set up a dozen of expectations for the requests, and also what response should be sent by the server to the client.

Requests

There are three different types:

• permanent: this will be always served when there's match for this request, you can make as many HTTP requests as you want
• oneshot: this will be served only once when there's a match for this request, you can only make 1 HTTP request
• ordered: same as oneshot but the order must be strictly matched to the order of setting up

You can also fine-tune the expected request. The following can be specified:

• URI (this is a must)
• HTTP method
• headers
• query string
• data (HTTP body of the request)
• JSON (HTTP body loaded as JSON)

Responses

Once you have the expectations for the request set up, you should also define the response you want to send back. The following is supported currently:

• respond arbitrary data (string or bytearray)
• respond a json (a python dict converted in-place to json)
• respond a Response object of werkzeug
• use your own function

Similar to requests, you can fine-tune what response you want to send:

• HTTP status
• headers
• data

Behave support

Using the BlockingHTTPServer class, the assertion for a request and the response can be performed in real order. For more info, see the test, the howto and the API documentation.

Missing features

• HTTP/2
• Keepalive
• TLS

Donation

Currently, this project is based heavily on werkzeug and pytest.

Werkzeug does all the heavy lifting behind the scenes, parsing HTTP request and defining Request and Response objects, which are currently transparent in the API.

If you wish to donate to werkzeug: https://palletsprojects.com/donate

Pytest is the de-facto test library for python.

If you wish to donate to pytest: https://opencollective.com/pytest