1 files changed, 45 insertions, 0 deletions
diff --git a/lib/gitlab/graphql/deprecations.rb b/lib/gitlab/graphql/deprecations.rb
new file mode 100644
index 00000000000..9cd8462f2e8
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+++ b/lib/gitlab/graphql/deprecations.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+# Concern for handling GraphQL deprecations.
+# https://docs.gitlab.com/ee/development/api_graphql_styleguide.html#deprecating-schema-items
+module Gitlab
+  module Graphql
+    module Deprecations
+      extend ActiveSupport::Concern
+
+      included do
+        attr_accessor :deprecation
+      end
+
+      def visible?(ctx)
+        super && ctx[:remove_deprecated] == true ? deprecation.nil? : true
+      end
+
+      private
+
+      # Set deprecation, mutate the arguments
+      def init_gitlab_deprecation(kwargs)
+        if kwargs[:deprecation_reason].present?
+          raise ArgumentError, <<~ERROR
+            Use `deprecated` property instead of `deprecation_reason`. See
+            #{Rails.application.routes.url_helpers.help_page_url('development/api_graphql_styleguide', anchor: 'deprecating-schema-items')}
+          ERROR
+        end
+
+        # GitLab allows items to be marked as "alpha", which leverages GraphQL deprecations.
+        # TODO remove
+        deprecation_args = kwargs.extract!(:alpha, :deprecated)
+
+        self.deprecation = Deprecation.parse(**deprecation_args)
+        return unless deprecation
+
+        unless deprecation.valid?
+          raise ArgumentError, "Bad deprecation. #{deprecation.errors.full_messages.to_sentence}"
+        end
+
+        kwargs[:deprecation_reason] = deprecation.deprecation_reason
+        kwargs[:description] = deprecation.edit_description(kwargs[:description])
+      end
+    end
+  end
+end