Add a class that represents a git push operation

app/services/merge_requests/base_service.rb

@@ -57,10 +57,10 @@ module MergeRequests
     # Returns all origin and fork merge requests from `@project` satisfying passed arguments.
     # rubocop: disable CodeReuse/ActiveRecord
     def merge_requests_for(source_branch, mr_states: [:opened])
-      MergeRequest
+      @project.source_of_merge_requests
         .with_state(mr_states)
-        .where(source_branch: source_branch, source_project_id: @project.id)
-        .preload(:source_project) # we don't need a #includes since we're just preloading for the #select
+        .where(source_branch: source_branch)
+        .preload(:source_project) # we don't need #includes since we're just preloading for the #select
         .select(&:source_project)
     end
     # rubocop: enable CodeReuse/ActiveRecord

lib/gitlab/git/push.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Git
+    class Push
+      def initialize(project, oldrev, newrev, ref)
+        @project, @oldrev, @newrev = project, oldrev, newrev
+        @repository = project.repository
+        @branch_name = Gitlab::Git.ref_name(ref)
+      end
+
+      def branch_added?
+        Gitlab::Git.blank_ref?(@oldrev)
+      end
+
+      def branch_removed?
+        Gitlab::Git.blank_ref?(@newrev)
+      end
+
+      def force_push?
+        Gitlab::Checks::ForcePush.force_push?(@project, @oldrev, @newrev)
+      end
+    end
+  end
+end