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