1 files changed, 44 insertions, 0 deletions
diff --git a/lib/gitlab/routing.rb b/lib/gitlab/routing.rb
index 632e2d87500..2c994536060 100644
--- a/lib/gitlab/routing.rb
+++ b/lib/gitlab/routing.rb
@@ -2,10 +2,35 @@ module Gitlab
   module Routing
     extend ActiveSupport::Concern
 
+    mattr_accessor :_includers
+    self._includers = []
+
     included do
+      Gitlab::Routing.includes_helpers(self)
+
       include Gitlab::Routing.url_helpers
     end
 
+    def self.includes_helpers(klass)
+      self._includers << klass
+    end
+
+    def self.add_helpers(mod)
+      url_helpers.include mod
+      url_helpers.extend mod
+
+      GitlabRoutingHelper.include mod
+      GitlabRoutingHelper.extend mod
+
+      app_url_helpers = Gitlab::Application.routes.named_routes.url_helpers_module
+      app_url_helpers.include mod
+      app_url_helpers.extend mod
+
+      _includers.each do |klass|
+        klass.include mod
+      end
+    end
+
     # Returns the URL helpers Module.
     #
     # This method caches the output as Rails' "url_helpers" method creates an
@@ -15,5 +40,24 @@ module Gitlab
     def self.url_helpers
       @url_helpers ||= Gitlab::Application.routes.url_helpers
     end
+
+    def self.redirect_legacy_paths(router, *paths)
+      build_redirect_path = lambda do |request, _params, path|
+        # Only replace the last occurence of `path`.
+        #
+        # `request.fullpath` includes the querystring
+        new_path = request.path.sub(%r{/#{path}(/*)(?!.*#{path})}, "/-/#{path}\\1")
+        new_path << "?#{request.query_string}" if request.query_string.present?
+
+        new_path
+      end
+
+      paths.each do |path|
+        router.match "/#{path}(/*rest)",
+                     via: [:get, :post, :patch, :delete],
+                     to: router.redirect { |params, request| build_redirect_path.call(request, params, path) },
+                     as: "legacy_#{path}_redirect"
+      end
+    end
   end
 end