sriprasanna / vcrpy Goto Github PK

#VCR.py

This is a proof-of-concept start at a Python version of Ruby's VCR library.

##What it is supposed to do Simplify testing by recording all HTTP interactions and saving them to "cassette" files, which are just yaml files. Then when you run your tests again, they all just hit the text files instead of the internet. This speeds up your tests and lets you work offline.

##Compatibility Notes This should work with Python 2.6 and 2.7. It also seems to work with pypy.

Currently I've only tested this (a little bit) with urllib2. It's known to NOT WORK with urllib.

##How to use it

import vcr
import urllib2

with vcr.use_cassette('fixtures/vcr_cassettes/synopsis.yaml'):
    response = urllib2.urlopen('http://www.iana.org/domains/example/').read()
    assert 'Example Domains' in response

Run this test once, and VCR.py will record the http request to fixtures/vcr_cassettes/synopsis.yml. Run it again, and VCR.py will replay the response from iana.org when the http request is made. This test is now fast (no real HTTP requests are made anymore), deterministic (the test will continue to pass, even if you are offline, or iana.org goes down for maintenance) and accurate (the response will contain the same headers and body you get from a real request).

##Ruby VCR compatibility I'm not trying to match the format of the YAML files. Cassettes generated by Ruby's VCR are not compatible with VCR.py. The API is similar but VCR.py doesn't have nearly as many features.

##Known Issues

• Probably only works with urllib2.
• Loading a HTTPS url and then a HTTP url in the same cassette will cause the second load to use the data from the HTTPS version of the URL: Issue #3
• Loading urls that do a 301/302 redirect don't work: Issue #4
• I haven't tested PUT/DELETE requests

##Similar libraries in Python Neither of these really implement the API I want, but I have cribbed some code from them.

• https://github.com/bbangert/Dalton
• https://github.com/storborg/replaylib

#License This library uses the MIT license