1 files changed, 34 insertions, 0 deletions
diff --git a/lib/gitlab/checks/base_single_checker.rb b/lib/gitlab/checks/base_single_checker.rb
new file mode 100644
index 00000000000..f93902055c9
--- /dev/null
+++ b/lib/gitlab/checks/base_single_checker.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Checks
+    class BaseSingleChecker < BaseChecker
+      attr_reader :change_access
+      delegate(*SingleChangeAccess::ATTRIBUTES, to: :change_access)
+
+      def initialize(change_access)
+        @change_access = change_access
+      end
+
+      private
+
+      def creation?
+        Gitlab::Git.blank_ref?(oldrev)
+      end
+
+      def deletion?
+        Gitlab::Git.blank_ref?(newrev)
+      end
+
+      def update?
+        !creation? && !deletion?
+      end
+
+      def tag_exists?
+        project.repository.tag_exists?(tag_name)
+      end
+    end
+  end
+end
+
+Gitlab::Checks::BaseSingleChecker.prepend_mod_with('Gitlab::Checks::BaseSingleChecker')