What is HTTPretty ?¶
Once upon a time a python developer wanted to use a RESTful api, everything was fine but until the day he needed to test the code that hits the RESTful API: what if the API server is down? What if its content has changed ?
Don’t worry, HTTPretty is here for you:
import logging
import requests
import httpretty
from sure import expect
logging.getLogger('httpretty.core').setLevel(logging.DEBUG)
@httpretty.activate(allow_net_connect=False)
def test_yipit_api_returning_deals():
httpretty.register_uri(httpretty.GET, "http://api.yipit.com/v1/deals/",
body='[{"title": "Test Deal"}]',
content_type="application/json")
response = requests.get('http://api.yipit.com/v1/deals/')
expect(response.json()).to.equal([{"title": "Test Deal"}])
A more technical description¶
HTTPretty is a python library that swaps the modules socket
and ssl
with fake implementations that intercept HTTP
requests at the level of a TCP connection.
It is inspired on Ruby’s FakeWeb.
If you come from the Ruby programming language this would probably sound familiar :smiley:
Demo¶
expecting a simple response body¶
import requests
import httpretty
def test_one():
httpretty.enable(verbose=True, allow_net_connect=False) # enable HTTPretty so that it will monkey patch the socket module
httpretty.register_uri(httpretty.GET, "http://yipit.com/",
body="Find the best daily deals")
response = requests.get('http://yipit.com')
assert response.text == "Find the best daily deals"
httpretty.disable() # disable afterwards, so that you will have no problems in code that uses that socket module
httpretty.reset() # reset HTTPretty state (clean up registered urls and request history)
making assertions in a callback that generates the response body¶
import requests
import json
import httpretty
@httpretty.activate
def test_with_callback_response():
def request_callback(request, uri, response_headers):
content_type = request.headers.get('Content-Type')
assert request.body == '{"nothing": "here"}', 'unexpected body: {}'.format(request.body)
assert content_type == 'application/json', 'expected application/json but received Content-Type: {}'.format(content_type)
return [200, response_headers, json.dumps({"hello": "world"})]
httpretty.register_uri(
httpretty.POST, "https://httpretty.example.com/api",
body=request_callback)
response = requests.post('https://httpretty.example.com/api', headers={'Content-Type': 'application/json'}, data='{"nothing": "here"}')
expect(response.json()).to.equal({"hello": "world"})
Link headers¶
Tests link headers by using the adding_headers parameter.
import requests from sure import expect import httpretty @httpretty.activate def test_link_response(): first_url = "http://foo-api.com/data" second_url = "http://foo-api.com/data?page=2" link_str = "<%s>; rel='next'" % second_url httpretty.register_uri( httpretty.GET, first_url, body='{"success": true}', status=200, content_type="text/json", adding_headers={"Link": link_str}, ) httpretty.register_uri( httpretty.GET, second_url, body='{"success": false}', status=500, content_type="text/json", ) # Performs a request to `first_url` followed by some testing response = requests.get(first_url) expect(response.json()).to.equal({"success": True}) expect(response.status_code).to.equal(200) next_url = response.links["next"]["url"] expect(next_url).to.equal(second_url) # Follow the next URL and perform some testing. response2 = requests.get(next_url) expect(response2.json()).to.equal({"success": False}) expect(response2.status_code).to.equal(500)
Motivation¶
When building systems that access external resources such as RESTful webservices, XMLRPC or even simple HTTP requests, we stumble in the problem:
“I’m gonna need to mock all those requests”
It can be a bit of a hassle to use something like
mock.Mock
to stub the requests, this can work well for
low-level unit tests but when writing functional or integration tests
we should be able to allow the http calls to go through the TCP socket
module.
HTTPretty monkey patches Python’s
socket
core module with a fake version of the module.
Because HTTPretty implements a fake the modules socket
and
ssl
you can use write tests to code against any HTTP library
that use those modules.