Feature: Dynamic ERB cassettes By default, cassettes are static: the exact response that was received when the cassette was recorded will be replayed for all future requests. Usually, this is fine, but in some cases you need something more dynamic. You can use ERB for this. To enable ERB evaluation of a cassette, pass the `:erb => true` option to a cassette. If you want to pass variables to the cassette, you can pass the names and values of the variables in a hash (`:erb => { ... }`). Scenario: Enable dynamic ERB cassette evalutation using :erb => true Given a previously recorded cassette file "cassettes/dynamic.yml" with: """ --- http_interactions: - request: method: get uri: http://example.com/foo?a=<%= 'b' * 3 %> body: encoding: UTF-8 string: '' headers: {} response: status: code: 200 message: OK headers: Content-Type: - text/html;charset=utf-8 Content-Length: - '9' body: encoding: UTF-8 string: Hello <%= 'bar'.next %> http_version: '1.1' recorded_at: Tue, 01 Nov 2011 04:58:44 GMT recorded_with: VCR 2.0.0 """ And a file named "dynamic_erb_example.rb" with: """ruby require 'vcr' VCR.configure do |c| c.hook_into :webmock c.cassette_library_dir = 'cassettes' end VCR.use_cassette('dynamic', :erb => true) do response = Net::HTTP.get_response('example.com', '/foo?a=bbb') puts "Response: #{response.body}" end """ When I run `ruby dynamic_erb_example.rb` Then it should pass with "Response: Hello bas" Scenario: Pass arguments to the ERB using :erb => { ... } Given a previously recorded cassette file "cassettes/dynamic.yml" with: """ --- http_interactions: - request: method: get uri: http://example.com/foo?a=<%= arg1 %> body: encoding: UTF-8 string: '' headers: {} response: status: code: 200 message: OK headers: Content-Type: - text/html;charset=utf-8 Content-Length: - '9' body: encoding: UTF-8 string: Hello <%= arg2 %> http_version: '1.1' recorded_at: Tue, 01 Nov 2011 04:58:44 GMT recorded_with: VCR 2.0.0 """ And a file named "dynamic_erb_example.rb" with: """ruby require 'vcr' VCR.configure do |c| c.hook_into :webmock c.cassette_library_dir = 'cassettes' end VCR.use_cassette('dynamic', :erb => { :arg1 => 7, :arg2 => 'baz' }) do response = Net::HTTP.get_response('example.com', '/foo?a=7') puts "Response: #{response.body}" end """ When I run `ruby dynamic_erb_example.rb` Then it should pass with "Response: Hello baz"