Use version from each of the accept headers, not only first one

lib/travis/api/app/responders/json.rb

@@ -25,13 +25,17 @@ class Travis::Api::App
         end
 
         def builder
-          @builder ||= Travis::Api.builder(resource, { :version => accept_version }.merge(options))
+          @builder ||= Travis::Api.builder(resource, { :version => version }.merge(options))
         end
 
         def accept_params
           (options[:accept].params || {}).symbolize_keys
         end
 
+        def version
+          options[:accept].version || Travis::Api::App::Helpers::Accept::DEFAULT_VERSION
+        end
+
         def params
           (request.params || {}).merge(accept_params)
         end

spec/integration/version_spec.rb

@@ -0,0 +1,26 @@
+require 'spec_helper'
+
+describe 'App' do
+  before do
+    add_endpoint '/foo' do
+      get '/' do
+        respond_with foo: 'bar'
+      end
+    end
+  end
+
+  it 'uses version from current accept header' do
+    Travis::Api.expects(:builder).with { |r, options| options[:version] == 'v1' }
+
+    Travis::Api::App::Responders::Json.any_instance.stubs(:apply?).
+        returns(false).then.returns(true)
+
+    response = get '/foo', {}, 'HTTP_ACCEPT' => 'application/json; version=2, application/json; version=1'
+    response.content_type.should == 'application/json;charset=utf-8'
+  end
+
+  it 'uses v1 by default' do
+    Travis::Api.expects(:builder).with { |r, options| options[:version] == 'v1' }
+    get '/foo', {}, 'HTTP_ACCEPT' => 'application/json'
+  end
+end