Introduction

Last updated 5 years ago

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Introduction

vcr

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

Help Wanted

We're looking for more maintainers. If you'd like to help maintain a well-used gem please spend some time reviewing pull requests, issues, or participating in discussions.

Usage

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

VCR.configure do |config|
  config.cassette_library_dir = "fixtures/vcr_cassettes"
  config.hook_into :webmock
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").

Rails and Minitest: 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:
Supports multiple HTTP libraries:
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.
Optionally 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.
Supports filtering sensitive data from the response body

The docs come in two flavors:

Release Policy

Ruby Interpreter Compatibility

VCR versions 6.x are tested on the following ruby interpreters:

MRI 2.4
MRI 2.5
MRI 2.6

Note that as of VCR 6, only 2.3+ is explicitly supported.

Development

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.
guide for instructions on running the specs and features.
To generate while developing: