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.

ee/lib/ee/api/helpers/search_helpers.rb

+# frozen_string_literal: true
+
+module EE
+  module API
+    module Helpers
+      module SearchHelpers
+        extend ActiveSupport::Concern
+
+        class_methods do
+          extend ::Gitlab::Utils::Override
+
+          override :global_search_scopes
+          def global_search_scopes
+            ['wiki_blobs', 'blobs', 'commits', *super]
+          end
+
+          override :group_search_scopes
+          def group_search_scopes
+            ['wiki_blobs', 'blobs', 'commits', *super]
+          end
+        end
+      end
+    end
+  end
+end

ee/lib/ee/api/search.rb

+# frozen_string_literal: true
+
+module EE
+  module API
+    module Search
+      extend ActiveSupport::Concern
+
+      prepended do
+        helpers do
+          extend ::Gitlab::Utils::Override
+
+          ELASTICSEARCH_SCOPES = %w(wiki_blobs blobs commits).freeze
+
+          override :verify_search_scope!
+          def verify_search_scope!
+            if ELASTICSEARCH_SCOPES.include?(params[:scope]) && !elasticsearch?
+              render_api_error!({ error: 'Scope not supported without Elasticsearch!' }, 400)
+            end
+          end
+
+          def elasticsearch?
+            ::Gitlab::CurrentSettings.elasticsearch_search?
+          end
+
+          override :process_results
+          def process_results(results)
+            return [] if results.empty?
+
+            if results.is_a?(::Elasticsearch::Model::Response::Response)
+              return paginate(results).map { |blob| ::Gitlab::Elastic::SearchResults.parse_search_result(blob) }
+            end
+
+            super
+          end
+        end
+      end
+    end
+  end
+end

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
+
+API::Helpers::SearchHelpers.prepend(EE::API::Helpers::SearchHelpers)

lib/api/search.rb

@@ -20,8 +20,6 @@ module API
         snippet_blobs: Entities::Snippet
       }.freeze
 
-      ELASTICSEARCH_SCOPES = %w(wiki_blobs blobs commits).freeze
-
       def search(additional_params = {})
         search_params = {
           scope: params[:scope],
@@ -37,12 +35,6 @@ module API
       end
 
       def process_results(results)
-        return [] if results.empty?
-
-        if results.is_a?(Elasticsearch::Model::Response::Response)
-          return paginate(results).map { |blob| Gitlab::Elastic::SearchResults.parse_search_result(blob) }
-        end
-
         paginate(results)
       end
 
@@ -54,14 +46,10 @@ module API
         SCOPE_ENTITY[params[:scope].to_sym]
       end
 
-      def check_elasticsearch_scope!
-        if ELASTICSEARCH_SCOPES.include?(params[:scope]) && !elasticsearch?
-          render_api_error!({ error: 'Scope not supported without Elasticsearch!' }, 400)
-        end
-      end
-
-      def elasticsearch?
-        Gitlab::CurrentSettings.elasticsearch_search?
+      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
 
@@ -73,15 +61,12 @@ 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,
-            if Elasticsearch enabled: wiki_blobs, blobs, commits',
-          values: %w(projects issues merge_requests milestones snippet_titles snippet_blobs
-                     wiki_blobs blobs commits)
+          desc: 'The scope of the search',
+          values: Helpers::SearchHelpers.global_search_scopes
         use :pagination
       end
       get do
-        check_elasticsearch_scope!
+        verify_search_scope!
 
         present search, with: entity
       end
@@ -96,14 +81,12 @@ 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,
-            if Elasticsearch enabled: wiki_blobs, blobs, commits',
-          values: %w(projects issues merge_requests milestones wiki_blobs blobs commits)
+          desc: 'The scope of the search',
+          values: Helpers::SearchHelpers.group_search_scopes
         use :pagination
       end
       get ':id/(-/)search' do
-        check_elasticsearch_scope!
+        verify_search_scope!
 
         present search(group_id: user_group.id), with: entity
       end
@@ -118,9 +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
@@ -129,3 +111,5 @@ module API
     end
   end
 end
+
+API::Search.prepend(EE::API::Search)