Add single merge request diff API endpoint

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/api/merge_request_diffs.rb b/lib/api/merge_request_diffs.rb
index a2f92f81107..07435d78468 100644
--- a/lib/api/merge_request_diffs.rb
+++ b/lib/api/merge_request_diffs.rb
@@ -21,6 +21,25 @@ module API
         authorize! :read_merge_request, merge_request
         present merge_request.merge_request_diffs, with: Entities::MergeRequestDiff
       end
+
+      desc 'Get a single merge request diff version' do
+        detail 'This feature was introduced in GitLab 8.12.'
+        success Entities::MergeRequestDiffFull
+      end
+
+      params do
+        requires :id, type: String, desc: 'The ID of a project'
+        requires :merge_request_id, type: Integer, desc: 'The ID of a merge request'
+        requires :version_id, type: Integer, desc: 'The ID of a merge request diff version'
+      end
+
+      get ":id/merge_requests/:merge_request_id/versions/:version_id" do
+        merge_request = user_project.merge_requests.
+          find(params[:merge_request_id])
+
+        authorize! :read_merge_request, merge_request
+        present merge_request.merge_request_diffs.find(params[:version_id]), with: Entities::MergeRequestDiffFull
+      end
     end
   end
 end