API version can now take an array of versions.

CHANGELOG.md

@@ -1,14 +1,19 @@
 Next Release
 ============
+
 #### Features
 
 * Grape is no longer tested against Ruby 1.8.7.
+* [#442](https://github.com/intridea/grape/issues/442): Enable incrementally building on top of a previous API version - [@dblock](https://github.com/dblock).
+* [#442](https://github.com/intridea/grape/issues/442): API `version` can now take an array of multiple versions - [@dblock](https://github.com/dblock).
+
 * Your contribution here.
 
 #### Fixes
 
 * [#428](https://github.com/intridea/grape/issues/428): Removes memoization from `Grape::Request` params to prevent middleware from freezing parameter values before `Formatter` can get them - [@mbleigh](https://github.com/mbleigh).
 
+
 0.5.0 (6/14/2013)
 =================
 

lib/grape/endpoint.rb

@@ -433,7 +433,7 @@ def build_middleware
 
       if settings[:version]
         b.use Grape::Middleware::Versioner.using(settings[:version_options][:using]), {
-          :versions        => settings[:version],
+          :versions        => settings[:version] ? settings[:version].flatten : nil,
           :version_options => settings[:version_options],
           :prefix          => settings[:root_prefix]
         }

lib/grape/middleware/versioner/header.rb

@@ -99,8 +99,8 @@ def strict?
         # of routes (see [Rack::Mount](https://github.com/josh/rack-mount) for more information). To prevent
         # this behavior, and not add the `X-Cascade` header, one can set the `:cascade` option to `false`.
         def cascade?
-          options[:version_options] && options[:version_options].has_key?(:cascade) ? 
-            !! options[:version_options][:cascade] : 
+          options[:version_options] && options[:version_options].has_key?(:cascade) ?
+            !! options[:version_options][:cascade] :
             true
         end
 

spec/grape/api_spec.rb

@@ -275,7 +275,15 @@ def subject.enable_root_route!
         subject.version 'v1', :using => :header, :vendor => 'test'
         subject.enable_root_route!
 
-        versioned_get "/", "v1", :using => :header
+        versioned_get "/", "v1", :using => :header, :vendor => 'test'
+      end
+
+      it 'header versioned APIs with multiple headers' do
+        subject.version ['v1', 'v2'], :using => :header, :vendor => 'test'
+        subject.enable_root_route!
+
+        versioned_get "/", "v1", :using => :header, :vendor => 'test'
+        versioned_get "/", "v2", :using => :header, :vendor => 'test'
       end
 
       it 'param versioned APIs' do

spec/grape/middleware/versioner/header_spec.rb

@@ -274,4 +274,29 @@
       subject.call('HTTP_ACCEPT' => 'application/vnd.vendor-v1+json').first.should == 200
     end
   end
+
+  context 'when multiple versions are specified' do
+    before do
+      @options[:versions] = ['v1', 'v2']
+    end
+
+    it 'succeeds with v1' do
+      subject.call('HTTP_ACCEPT' => 'application/vnd.vendor-v1+json').first.should == 200
+    end
+
+    it 'succeeds with v2' do
+      subject.call('HTTP_ACCEPT' => 'application/vnd.vendor-v2+json').first.should == 200
+    end
+
+    it 'fails with another version' do
+      expect {
+        subject.call('HTTP_ACCEPT' => 'application/vnd.vendor-v3+json')
+      }.to throw_symbol(
+        :error,
+        :status => 406,
+        :headers => {'X-Cascade' => 'pass'},
+        :message => 'API vendor or version not found.'
+      )
+    end
+  end
 end

spec/support/versioned_helpers.rb

@@ -25,7 +25,10 @@ def versioned_headers(options)
     {}  # no-op
   when :header
     {
-      'HTTP_ACCEPT' => "application/vnd.#{options[:vendor]}-#{options[:version]}+#{options[:format]}"
+      'HTTP_ACCEPT' => [
+        "application/vnd.#{options[:vendor]}-#{options[:version]}",
+        options[:format]
+      ].compact.join("+")
     }
   when :accept_version_header
     {
@@ -41,7 +44,7 @@ def versioned_get(path, version_name, version_options = {})
   headers = versioned_headers(version_options.merge(:version => version_name))
   params = {}
   if version_options[:using] == :param
-    params = { version_options[:parameter] => version_name } 
+    params = { version_options[:parameter] => version_name }
   end
   get path, params, headers
 end