Refactor API::Search for EE

This refactors API::Search so that Enterprise Edition can more easily
extend its functionality, without having to modify the file directly.

lib/api/helpers/search_helpers.rb

+# frozen_string_literal: true
+
+module API
+  module Helpers
+    module SearchHelpers
+      def self.global_search_scopes
+        # This is a separate method so that EE can redefine it.
+        %w(projects issues merge_requests milestones snippet_titles snippet_blobs)
+      end
+
+      def self.group_search_scopes
+        # This is a separate method so that EE can redefine it.
+        %w(projects issues merge_requests milestones)
+      end
+
+      def self.project_search_scopes
+        # This is a separate method so that EE can redefine it.
+        %w(issues merge_requests milestones notes wiki_blobs commits blobs)
+      end
+    end
+  end
+end

lib/api/search.rb

@@ -45,6 +45,12 @@ module API
       def entity
         SCOPE_ENTITY[params[:scope].to_sym]
       end
+
+      def verify_search_scope!
+        # In EE we have additional validation requirements for searches.
+        # Defining this method here as a noop allows us to easily extend it in
+        # EE, without having to modify this file directly.
+      end
     end
 
     resource :search do
@@ -55,12 +61,13 @@ module API
         requires :search, type: String, desc: 'The expression it should be searched for'
         requires :scope,
           type: String,
-          desc: 'The scope of search, available scopes:
-            projects, issues, merge_requests, milestones, snippet_titles, snippet_blobs',
-          values: %w(projects issues merge_requests milestones snippet_titles snippet_blobs)
+          desc: 'The scope of the search',
+          values: Helpers::SearchHelpers.global_search_scopes
         use :pagination
       end
       get do
+        verify_search_scope!
+
         present search, with: entity
       end
     end
@@ -74,12 +81,13 @@ module API
         requires :search, type: String, desc: 'The expression it should be searched for'
         requires :scope,
           type: String,
-          desc: 'The scope of search, available scopes:
-            projects, issues, merge_requests, milestones',
-          values: %w(projects issues merge_requests milestones)
+          desc: 'The scope of the search',
+          values: Helpers::SearchHelpers.group_search_scopes
         use :pagination
       end
       get ':id/(-/)search' do
+        verify_search_scope!
+
         present search(group_id: user_group.id), with: entity
       end
     end
@@ -93,9 +101,8 @@ module API
         requires :search, type: String, desc: 'The expression it should be searched for'
         requires :scope,
           type: String,
-          desc: 'The scope of search, available scopes:
-            issues, merge_requests, milestones, notes, wiki_blobs, commits, blobs',
-          values: %w(issues merge_requests milestones notes wiki_blobs commits blobs)
+          desc: 'The scope of the search',
+          values: Helpers::SearchHelpers.project_search_scopes
         use :pagination
       end
       get ':id/(-/)search' do