add Octokit.update_ref method, fixtures and specs

lib/octokit/client/refs.rb

@@ -47,6 +47,24 @@ def create_ref(repo, ref, sha, options={})
         post("repos/#{Repository.new(repo)}/git/refs", options.merge(parameters))
       end
 
+      # Update a reference
+      #
+      # @param repo [String, Repository, Hash] A GitHub repository
+      # @param ref [String] The ref, e.g. <tt>tags/v0.0.3</tt>
+      # @param sha [String] A SHA, e.g. <tt>827efc6d56897b048c772eb4087f854f46256132</tt>
+      # @param force [Boolean] A flag indicating one wants to force the update to make sure the update is a fast-forward update.
+      # @return [Array] The list of references updated
+      # @see http://developer.github.com/v3/git/refs/
+      # @example Force update heads/sc/featureA for octocat/Hello-World with sha aa218f56b14c9653891f9e74264a383fa43fefbd
+      #   Octokit.update_ref("octocat/Hello-World","heads/sc/featureA", "aa218f56b14c9653891f9e74264a383fa43fefbd")
+      def update_ref(repo, ref, sha, force=true, options={})
+        parameters = {
+          :sha  => sha,
+          :force => force
+        }
+        patch("repos/#{Repository.new(repo)}/git/refs/#{ref}", options.merge(parameters))
+      end
+
     end
   end
 end

spec/fixtures/v3/ref_update.json

@@ -0,0 +1,11 @@
+[
+  {
+    "ref": "refs/heads/sc/featureA",
+    "url": "https://api.github.com/repos/octocat/Hello-World/git/refs/heads/sc/featureA",
+    "object": {
+      "type": "commit",
+      "sha": "aa218f56b14c9653891f9e74264a383fa43fefbd",
+      "url": "https://api.github.com/repos/octocat/Hello-World/git/commits/aa218f56b14c9653891f9e74264a383fa43fefbd"
+    }
+  }
+]

spec/octokit/client/refs_spec.rb

@@ -51,5 +51,18 @@
 
   end
 
+  describe ".update_ref" do
+
+    it "should update a ref" do
+      stub_patch("/repos/octocat/Hello-World/git/refs/heads/sc/featureA").
+        with(:body => { "sha" => "aa218f56b14c9653891f9e74264a383fa43fefbd", "force" => true },
+             :headers => {'Content-Type'=>'application/json'}).
+        to_return(:body => fixture("v3/ref_update.json"))
+      refs = @client.update_ref("octocat/Hello-World","heads/sc/featureA", "aa218f56b14c9653891f9e74264a383fa43fefbd", true)
+      refs.first.ref.should eq("refs/heads/sc/featureA")
+      refs.first.object.sha.should eq("aa218f56b14c9653891f9e74264a383fa43fefbd")
+    end
+  end
+
 end