Add compare branches endpoint to API

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

2 files changed, 33 insertions, 0 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 457af52fe9d..eead8b18ebd 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -194,5 +194,22 @@ module API
     class Label < Grape::Entity
       expose :name
     end
+
+    class RepoDiff < Grape::Entity
+      expose :old_path, :new_path, :a_mode, :b_mode, :diff
+      expose :new_file, :renamed_file, :deleted_file
+    end
+
+    class Compare < Grape::Entity
+      expose :commit, using: Entities::RepoCommit do |compare, options|
+        Commit.new compare.commit
+      end
+      expose :commits, using: Entities::RepoCommit do |compare, options|
+        Commit.decorate compare.commits
+      end
+      expose :diffs, using: Entities::RepoDiff do |compare, options|
+        compare.diffs
+      end
+    end
   end
 end
diff --git a/lib/api/repositories.rb b/lib/api/repositories.rb
index 076a9ceeb74..d59c25cf316 100644
--- a/lib/api/repositories.rb
+++ b/lib/api/repositories.rb
@@ -15,6 +15,7 @@ module API
           not_found!
         end
       end
+
       # Get a project repository tags
       #
       # Parameters:
@@ -118,6 +119,21 @@ module API
           not_found!
         end
       end
+
+      # Compare two branches, tags or commits
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   from (required) - the commit sha or branch name
+      #   to (required) - the commit sha or branch name
+      # Example Request:
+      #   GET /projects/:id/repository/compare?from=master&to=feature
+      get ':id/repository/compare' do
+        authorize! :download_code, user_project
+        compare = Gitlab::Git::Compare.new(user_project.repository.raw_repository, params[:from], params[:to], MergeRequestDiff::COMMITS_SAFE_SIZE)
+
+        present compare, with: Entities::Compare
+      end
     end
   end
 end