vcr

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Record your test suite's HTTP interactions and replay them during future test runs for fast, deterministic, accurate tests.

Help Wanted

We looking for new maintainers. If you'd like to help maintain a well-used gem please join the vcr-maintainers google group.

Usage

require 'rubygems'
require 'test/unit'
require 'vcr'

VCR.configure do |config|
  config.cassette_library_dir = "fixtures/vcr_cassettes"
  config.hook_into :webmock # or :fakeweb
end

class VCRTest < Test::Unit::TestCase
  def test_example_dot_com
    VCR.use_cassette("synopsis") do
      response = Net::HTTP.get_response(URI('http://www.iana.org/domains/reserved'))
      assert_match /Example domains/, response.body
    end
  end
end

Run this test once, and VCR will record the HTTP request to fixtures/vcr_cassettes/synopsis.yml. Run it again, and VCR 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). You can use a different cassette library directory (e.g., "test/vcr_cassettes"), but do not use 'test/fixtures' as the directory if you're using Rails and minitest (Rails will instead transitively load any files in that directory as models).

Features

• Automatically records and replays your HTTP interactions with minimal setup/configuration code.
• Supports and works with the HTTP stubbing facilities of multiple libraries. Currently, the following are supported:
  • WebMock
  • Typhoeus
  • Faraday
  • Excon
  • FakeWeb (deprecated)
• Supports multiple HTTP libraries:
  • Patron (when using WebMock)
  • Curb (when using WebMock -- only supports Curl::Easy at the moment)
  • HTTPClient (when using WebMock)
  • em-http-request (when using WebMock)
  • Net::HTTP (when using FakeWeb and WebMock)
  • Typhoeus (Typhoeus::Hydra, but not Typhoeus::Easy or Typhoeus::Multi)
  • Excon
  • Faraday
  • And of course any library built on Net::HTTP, such as Mechanize, HTTParty or Rest Client.
• Request matching is configurable based on HTTP method, URI, host, path, body and headers, or you can easily implement a custom request matcher to handle any need.
• The same request can receive different responses in different tests--just use different cassettes.
• The recorded requests and responses are stored on disk in a serialization format of your choice (currently YAML and JSON are built in, and you can easily implement your own custom serializer) and can easily be inspected and edited.
• Dynamic responses are supported using ERB.
• Automatically re-records cassettes on a configurable regular interval to keep them fresh and current.
• Disables all HTTP requests that you don't explicitly allow.
• Simple Cucumber integration is provided using tags.
• Includes convenient RSpec macros and integration with RSpec 2 metadata.
• Known to work well with many popular Ruby libraries including RSpec 1 & 2, Cucumber, Test::Unit, Capybara, Mechanize, Rest Client and HTTParty.
• Includes Rack and Faraday middleware.

The docs come in two flavors:

• The relish docs contain example-based documentation (VCR's Cucumber suite, in fact). It's a good place to look when you are first getting started with VCR, or if you want to see an example of how to use a feature.
• The rubydoc.info docs contain API documentation. The API docs contain detailed info about all of VCR's public API.
• See the Upgrade doc for info about what's new and changed in VCR 2.0.

There is also a Railscast, which will get you up and running in no-time http://railscasts.com/episodes/291-testing-with-vcr.

Release Policy

VCR follows the principles of semantic versioning. The API documentation defines VCR's public API. Patch level releases contain only bug fixes. Minor releases contain backward-compatible new features. Major new releases contain backwards-incompatible changes to the public API.

Ruby Interpreter Compatibility

VCR has been tested on the following ruby interpreters:

• MRI 1.9.3
• MRI 2.0.0
• MRI 2.1
• MRI 2.2
• MRI 2.3.0
• JRuby
• Rubinius

Note that as of VCR 3, 1.8.7 and 1.9.2 are not supported.

Development

• Source hosted on GitHub.
• Direct questions and discussions to the mailing list.
• Report issues on GitHub Issues.
• Pull requests are very welcome! Please include spec and/or feature coverage for every patch, and create a topic branch for every separate change you make.
• See the Contributing guide for instructions on running the specs and features.
• Code quality metrics are checked by Code Climate.
• Documentation is generated with YARD (cheat sheet). To generate while developing:

yard server --reload

Ports in Other Languages

• Betamax (Python)
• VCR.py (Python)
• Betamax (Go)
• DVR (Go)
• Go VCR (Go)
• Betamax (Clojure)
• vcr-clj (Clojure)
• Betamax.NET (C#/.NET)
• ExVCR (Elixir)
• HAVCR (Haskell)
• Mimic (PHP/Kohana)
• PHP-VCR (PHP)
• Nock-VCR (JavaScript/Node)
• Sepia (Javascript/Node)
• VCR.js (JavaScript)
• NSURLConnectionVCR (Objective-C)
• VCRURLConnection (Objective-C)
• VHS (Erlang)
• Betamax (Java)
• http_replayer (Rust)

Related Projects

• Mr. Video (Rails engine for managing VCR cassettes and episodes)

Similar Libraries in Ruby

• Ephemeral Response
• Net::HTTP Spy
• NetRecorder
• Puffing Billy
• REST-assured
• Stale Fish
• WebFixtures

Credits

• Aslak Hellesøy for Cucumber.
• Bartosz Blimke for WebMock.
• Chris Kampmeier for FakeWeb.
• Chris Young for NetRecorder, the inspiration for VCR.
• David Balatero and Hans Hasselberg for help with Typhoeus support.
• Wesley Beary for help with Excon support.
• Jacob Green for help with ongoing VCR maintenance.
• Jan Berdajs and Daniel Berger for improvements to thread-safety.

Thanks also to the following people who have contributed patches or helpful suggestions:

• Aaron Brethorst
• Alexander Wenzowski
• Austen Ito
• Avdi Grimm
• Bartosz Blimke
• Benjamin Oakes
• Ben Hutton
• Bradley Isotope
• Carlos Kirkconnell
• Chad Jolly
• Chris Le
• Chris Gunther
• Eduardo Maia
• Eric Allam
• Ezekiel Templin
• Flaviu Simihaian
• Gordon Wilson
• Hans Hasselberg
• Herman Verschooten
• Ian Cordasco
• Ingemar
• Ilya Scharrenbroich
• Jacob Green
• James Bence
• Jay Shepherd
• Jeff Pollard
• Joe Nelson
• Jonathan Tron
• Justin Smestad
• Karl Baum
• Kris Luminar
• Kurt Funai
• Luke van der Hoeven
• Mark Burns
• Max Riveiro
• Michael Lavrisha
• Michiel de Mare
• Mike Dalton
• Mislav Marohnić
• Nathaniel Bibler
• Noah Davis
• Oliver Searle-Barnes
• Omer Rauchwerger
• Paco Guzmán
• Paul Morgan
• playupchris
• Ron Smith
• Ryan Bates
• Ryan Burrows
• Ryan Castillo
• Sathya Sekaran
• Scott Carleton
• Shay Frendt
• Steve Faulkner
• Stephen Anderson
• Todd Lunter
• Tyler Hunt
• Uģis Ozols
• vzvu3k6k
• Wesley Beary

Copyright

Copyright (c) 2010-2015 Myron Marston

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.