Getting Started

Install it

[sudo] gem install vcr
[sudo] gem install webmock

Configure it

Create a file named vcr_setup.rb with content like:

require 'vcr'

VCR.configure do |c|
  c.cassette_library_dir = 'vcr_cassettes'
  c.hook_into :webmock
end

Ensure this file is required by your test suite before any of the tests are run.

Use it

Run your tests. Any tests that make HTTP requests using Net::HTTP will raise errors like:

================================================================================
An HTTP request has been made that VCR does not know how to handle:
  GET http://example.com/

There is currently no cassette in use. There are a few ways
you can configure VCR to handle this request:

  * If you want VCR to record this request and play it back during future test
    runs, you should wrap your test (or this portion of your test) in a
    `VCR.use_cassette` block [1].
  * If you only want VCR to handle requests made while a cassette is in use,
    configure `allow_http_connections_when_no_cassette = true`. VCR will
    ignore this request since it is made when there is no cassette [2].
  * If you want VCR to ignore this request (and others like it), you can
    set an `ignore_request` callback [3].

[1] https://www.relishapp.com/myronmarston/vcr/v/2-0-0/docs/getting-started
[2] https://www.relishapp.com/myronmarston/vcr/v/2-0-0/docs/configuration/allow-http-connections-when-no-cassette
[3] https://www.relishapp.com/myronmarston/vcr/v/2-0-0/docs/configuration/ignore-request
================================================================================

Find one of these tests (preferably one that uses the same HTTP method and request URL every time--if not, you'll have to configure the request matcher). Wrap the body of it (or at least the code that makes the HTTP request) in a VCR.use_cassette block:

VCR.use_cassette('whatever cassette name you want') do
   # the body of the test would go here...
end

Run this test. It will record the HTTP request to disk as a cassette (a test fixture), with content like:

http_interactions:
- request:
    method: get
    uri: http://example.com/
    body: ''
    headers: {}
  response:
    status:
      code: 200
      message: OK
    headers:
      Content-Type:
      - text/html;charset=utf-8
      Content-Length:
      - '26'
    body: This is the response body
    http_version: '1.1'
  recorded_at: Tue, 01 Nov 2011 04:58:44 GMT
recorded_with: VCR 2.0.0

Disconnect your computer from the internet. Run the test again. It should pass since VCR is automatically replaying the recorded response when the request is made.