Logo: Relish

  1. Sign in

Project: Vcr 2.0.0.rc1

Publisher: VCR

Register and use a custom matcher

If the built-in matchers do not meet your needs, you can use a custom matcher.

Any 2-argument callable (that is, an object that responds to #call and accepts
2 arguments) can be a matcher. Simply put the callable in your
:match_requests_on array.

In addition, you can register a named custom matcher with VCR, and use
the name in your :match_requests_on array.

Either way, your custom matcher should return a truthy value if the
given requests should be considered equivalent.

Background
Given
a previously recorded cassette file "cassettes/example.yml" with: 
---
http_interactions:
- request:
    method: get
    uri: http://foo.com:9000/foo
    body: ''
    headers: {}
  response:
    status:
      code: 200
      message: OK
    headers:
      Content-Length:
      - '18'
    body: port 9000 response
    http_version: '1.1'
  recorded_at: Tue, 01 Nov 2011 04:58:44 GMT
- request:
    method: get
    uri: http://foo.com:8000/foo
    body: ''
    headers: {}
  response:
    status:
      code: 200
      message: OK
    headers:
      Content-Length:
      - '18'
    body: port 8000 response
    http_version: '1.1'
  recorded_at: Tue, 01 Nov 2011 04:58:44 GMT
recorded_with: VCR 2.0.0
Scenarios
Use a callable as a custom request matcher
And
a file named "callable_matcher.rb" with: 
include_http_adapter_for("http_lib")

require 'vcr'

VCR.configure do |c|
  configuration
  c.cassette_library_dir = 'cassettes'
end

port_matcher = lambda do |request_1, request_2|
  URI(request_1.uri).port == URI(request_2.uri).port
end

VCR.use_cassette('example', :match_requests_on => [:method, port_matcher]) do
  puts "Response for port 8000: " + response_body_for(:get, "http://example.com:8000/")
end

VCR.use_cassette('example', :match_requests_on => [:method, port_matcher]) do
  puts "Response for port 9000: " + response_body_for(:get, "http://example.com:9000/")
end
When
I run ruby callable_matcher.rb
Then
it should pass with: 
Response for port 8000: port 8000 response
Response for port 9000: port 9000 response
Examples:
configuration http_lib
c.hook_into :fakeweb net/http
c.hook_into :webmock net/http
c.hook_into :webmock httpclient
c.hook_into :webmock curb
c.hook_into :webmock patron
c.hook_into :webmock em-http-request
c.hook_into :webmock typhoeus
c.hook_into :typhoeus typhoeus
c.hook_into :excon excon
c.hook_into :faraday faraday (w/ net_http)
c.hook_into :faraday faraday (w/ typhoeus)
Register a named custom matcher
And
a file named "register_custom_matcher.rb" with: 
include_http_adapter_for("net/http")

require 'vcr'

VCR.configure do |c|
  c.hook_into :fakeweb
  c.cassette_library_dir = 'cassettes'
  c.register_request_matcher :port do |request_1, request_2|
    URI(request_1.uri).port == URI(request_2.uri).port
  end
end

VCR.use_cassette('example', :match_requests_on => [:method, :port]) do
  puts "Response for port 8000: " + response_body_for(:get, "http://example.com:8000/")
end

VCR.use_cassette('example', :match_requests_on => [:method, :port]) do
  puts "Response for port 9000: " + response_body_for(:get, "http://example.com:9000/")
end
When
I run ruby register_custom_matcher.rb
Then
it should pass with: 
Response for port 8000: port 8000 response
Response for port 9000: port 9000 response

Last published over 7 years ago by myronmarston.