VCR
1.0.0
1.0.0
  • Initial page
  • record_modes
    • :none
    • :new_episodes
    • :all
    • :once
  • test_frameworks
    • Usage with Test::Unit
    • Usage with Cucumber
    • Usage with RSpec metadata
  • request_matching
    • Matching on Headers
    • Matching on Body
    • Matching on Method
    • URI without param(s)
    • Identical requests are replayed in sequence
    • Matching on Body
    • Playback repeats
    • Matching on URI
    • Matching on Host
    • Matching on Path
    • Matching on Query string
    • Register and use a custom matcher
  • cassettes
    • exclusive cassette
    • Update content_length header
    • Error for HTTP request made when no cassette is in use
    • Naming
    • Allow Unused HTTP Interactions
    • Freezing Time
    • Decode compressed response
    • Dynamic ERB cassettes
    • Automatic Re-recording
    • Cassette format
  • configuration
    • hook_into
    • cassette_library_dir
    • Filter sensitive data
    • Ignore Request
    • Debug Logging
    • default_cassette_options
    • query_parser
    • uri_parser
    • Allow HTTP connections when no cassette
    • Preserve Exact Body Bytes
  • http_libraries
    • EM HTTP Request
    • Net::HTTP
  • hooks
    • before_playback hook
    • after_http_request hook
    • before_http_request hook
    • before_record hook
    • around_http_request hook
  • middleware
    • Faraday middleware
    • Rack
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  • Background ()
  • Match the URI on all but the timestamp query parameter

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  1. request_matching

URI without param(s)

A common source of difficulty when using VCR with the default matchers are non-deterministic URIs. If the URI changes on every test run (because it includes a timestamp parameter, or whatever), the default URI matcher will not work well for you.

You can write a custom matcher to match URIs however you want, but for the common need to match on a URI and ignore particular query parameters, VCR provides an easier way:

  :match_requests_on => [
    :method,
    VCR.request_matchers.uri_without_param(:timestamp)
  ]

uri_without_param also has a plural alias (i.e. uri_without_params(:timestamp, :session))

Background ()

Given a previously recorded cassette file "cassettes/example.yml" with:

--- 
http_interactions: 
- request: 
    method: get
    uri: http://example.com/search?q=foo&timestamp=1316920490
    body: 
      encoding: UTF-8
      string: ""
    headers: {}
  response: 
    status: 
      code: 200
      message: OK
    headers: 
      Content-Length: 
      - "12"
    body: 
      encoding: UTF-8
      string: foo response
    http_version: "1.1"
  recorded_at: Tue, 01 Nov 2011 04:58:44 GMT
- request: 
    method: get
    uri: http://example.com/search?q=bar&timestamp=1296723437
    body: 
      encoding: UTF-8
      string: ""
    headers: {}
  response: 
    status: 
      code: 200
      message: OK
    headers: 
      Content-Length: 
      - "12"
    body: 
      encoding: UTF-8
      string: bar response
    http_version: "1.1"
  recorded_at: Tue, 01 Nov 2011 04:58:44 GMT
recorded_with: VCR 2.0.0

Match the URI on all but the timestamp query parameter

And a file named "uri_without_param_matcher.rb" with:

include_http_adapter_for("net/http")

require 'vcr'

VCR.configure do |c|
  c.hook_into :webmock
  c.cassette_library_dir = 'cassettes'
  c.default_cassette_options = {
    :match_requests_on => [:method,
      VCR.request_matchers.uri_without_param(:timestamp)]
  }
end

def search_uri(q)
  "http://example.com/search?q=#{q}&timestamp=#{Time.now.to_i}"
end

VCR.use_cassette('example') do
  puts "Response for bar: " +
       response_body_for(:get, search_uri("bar"))
end

VCR.use_cassette('example') do
  puts "Response for foo: " +
       response_body_for(:get, search_uri("foo"))
end

When I run ruby uri_without_param_matcher.rb

Then it should pass with:

Response for bar: bar response
Response for foo: foo response
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Last updated 5 years ago

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