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Project: Vcr 1.7.1

stub_with

The stub_with configuration option determines which HTTP stubbing library
VCR will use. There are currently 4 supported stubbing libraries which
support many different HTTP libraries:

  • FakeWeb can be used to stub Net::HTTP.
  • WebMock can be used to stub:
    • Net::HTTP
    • HTTPClient
    • Patron
    • Curb (Curb::Easy, but not Curb::Multi)
    • EM HTTP Request
  • Typhoeus can be used to stub itself (as long as you use Typhoeus::Hydra, but not Typhoeus::Easy or Typhoeus::Multi).
  • Faraday can be used (in combination with the provided Faraday middleware) to stub requests made through Faraday (regardless of which Faraday HTTP adapter is used).

There are some addiitonal trade offs to consider when deciding which
stubbing library to use:

  • FakeWeb does not allow you to stub a request based on the headers or body. Therefore, the :match_requests_on option does not support :body or :headers when you use FakeWeb. Typhoeus, WebMock and Faraday both support matching on :body and :headers.
  • FakeWeb is currently about 4 times faster than WebMock for stubbing Net::HTTP (see benchmarks/http_stubbing_libraries.rb for details).
  • FakeWeb and WebMock both use extensive monkey patching to stub their supported HTTP libraries. No monkey patching is used for Typhoeus or Faraday.
  • FakeWeb and WebMock cannot both be used at the same time.
  • Typhoeus and Faraday can be used together, and with either FakeWeb or WebMock.

Regardless of which library you use, VCR takes care of all of the configuration
for you. You should not need to interact directly with FakeWeb, WebMock or the
stubbing facilities of Typhoeus or Faraday. If/when you decide to change stubbing
libraries (i.e. if you initially use FakeWeb because it's faster but later need the
additional features of WebMock) you can change the stub_with configuration
option and it'll work with no other changes required.

Scenarios
stub_with loads the given HTTP stubbing library
Given
a file named "vcr_stub_with.rb" with:
require 'vcr'

VCR.config do |c|
  c.stub_with stub_with
end

puts "FakeWeb Loaded: #{!!defined?(FakeWeb)}"
puts "WebMock Loaded: #{!!defined?(WebMock)}"
puts "Typhoeus Loaded: #{!!defined?(Typhoeus)}"
When
I run "ruby vcr_stub_with.rb"
Then
the output should contain:
FakeWeb Loaded: fakeweb_loaded
WebMock Loaded: webmock_loaded
Typhoeus Loaded: typhoeus_loaded
Examples:
stub_with fakeweb_loaded webmock_loaded typhoeus_loaded
:fakeweb true false false
:webmock false true false
:typhoeus false false true
Record and replay a request using each supported stubbing/http library combination
Given
a file named "stubbing_http_lib_combo.rb" with:
require 'vcr_cucumber_helpers'
include_http_adapter_for("http_lib")

start_sinatra_app(:port => 7777) do
  get('/') { ARGV[0] }
end

puts "The response for request 1 was: #{response_body_for(:get, "http://localhost:7777/")}"

require 'vcr'

VCR.config do |c|
  c.stub_with stub_with
  c.cassette_library_dir = 'vcr_cassettes'
end

VCR.use_cassette('example', :record => :new_episodes) do
  puts "The response for request 2 was: #{response_body_for(:get, "http://localhost:7777/")}"
end
When
I run "ruby stubbing_http_lib_combo.rb 'Hello World'"
Then
the output should contain each of the following:
The response for request 1 was: Hello World
The response for request 2 was: Hello World
And
the file "vcr_cassettes/example.yml" should contain "body: Hello World"
When
I run "ruby stubbing_http_lib_combo.rb 'Goodbye World'"
Then
the output should contain each of the following:
The response for request 1 was: Goodbye World
The response for request 2 was: Hello World
And
the file "vcr_cassettes/example.yml" should contain "body: Hello World"
Examples:
stub_with http_lib
:fakeweb net/http
:webmock net/http
:webmock httpclient
:webmock patron
:webmock curb
:webmock em-http-request
:typhoeus typhoeus
  • @exclude-jruby
Use Typhoeus and Faraday in combination with FakeWeb or WebMock
Given
a file named "stub_with_multiple.rb" with:
require 'vcr_cucumber_helpers'
require 'typhoeus'

start_sinatra_app(:port => 7777) do
  get('/:path') { "#{ARGV[0]} #{params[:path]}" }
end

def net_http_response
  Net::HTTP.get_response('localhost', '/net_http', 7777).body
end

def typhoeus_response
  Typhoeus::Request.get("http://localhost:7777/typhoeus").body
end

def faraday_response
  Faraday::Connection.new(:url => 'http://localhost:7777') do |builder|
    builder.use VCR::Middleware::Faraday do |cassette|
      cassette.name    'example'
      cassette.options :record => :new_episodes
    end

    builder.adapter :faraday_adapter
  end.get('/faraday').body
end

puts "Net::HTTP 1: #{net_http_response}"
puts "Typhoeus 1: #{typhoeus_response}"

require 'vcr'

VCR.config do |c|
  c.stub_with stub_with, :typhoeus, :faraday
  c.cassette_library_dir = 'vcr_cassettes'
end

VCR.use_cassette('example', :record => :new_episodes) do
  puts "Net::HTTP 2: #{net_http_response}"
  puts "Typhoeus 2: #{typhoeus_response}"
end

puts "Faraday: #{faraday_response}"
When
I run "ruby stub_with_multiple.rb 'Hello'"
Then
the output should contain each of the following:
Net::HTTP 1: Hello net_http
Typhoeus 1: Hello typhoeus
Net::HTTP 2: Hello net_http
Typhoeus 2: Hello typhoeus
Faraday: Hello faraday
And
the cassette "vcr_cassettes/example.yml" should have the following response bodies:
Hello net_http
Hello typhoeus
Hello faraday
When
I run "ruby stub_with_multiple.rb 'Goodbye'"
Then
the output should contain each of the following:
Net::HTTP 1: Goodbye net_http
Typhoeus 1: Goodbye typhoeus
Net::HTTP 2: Hello net_http
Typhoeus 2: Hello typhoeus
Faraday: Hello faraday
Examples:
stub_with faraday_adapter
:fakeweb net_http
:webmock net_http
:fakeweb typhoeus
:webmock typhoeus

Last published about 5 years ago by myronmarston.