From d697508e04e0547fb2e583d5e9ae431ec0817ef8 Mon Sep 17 00:00:00 2001
From: Kyrylo Silin <silin@kyrylo.org>
Date: Tue, 6 Aug 2019 17:34:15 +0800
Subject: [PATCH] rails/app: detect and attach engine name to routes

Fixes #988 (Add support for Rails engine route prefixes)
---
 CHANGELOG.md              |  3 +++
 lib/airbrake/rails/app.rb | 25 ++++++++++++++++---------
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc0cb2ca7..6463a38d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@ Airbrake Changelog
 
 ### master
 
+* Rails: engine routes are now being marked with the engine name prefix
+  ([#997](https://github.com/airbrake/airbrake/pull/997))
+
 ### [v9.4.1][v9.4.1] (August 5, 2019)
 
 * Started depending on airbrake-ruby
diff --git a/lib/airbrake/rails/app.rb b/lib/airbrake/rails/app.rb
index 5cb7839e1..527e9cf2b 100644
--- a/lib/airbrake/rails/app.rb
+++ b/lib/airbrake/rails/app.rb
@@ -8,26 +8,33 @@ class App
       Route = Struct.new(:path, :controller, :action)
 
       def routes
-        @routes ||= [*app_routes, *engine_routes].map do |route|
-          Route.new(
-            route.path.spec.to_s,
-            route.defaults[:controller],
-            route.defaults[:action]
-          )
+        @routes ||= app_routes.merge(engine_routes).flat_map do |(engine_name, routes)|
+          routes.map { |rails_route| build_route(engine_name, rails_route) }
         end
       end
 
       private
 
       def app_routes
-        ::Rails.application.routes.routes.routes
+        # Engine name is nil because this is default (non-engine) routes.
+        { nil => ::Rails.application.routes.routes.routes }
       end
 
       def engine_routes
-        ::Rails::Engine.subclasses.flat_map do |engine|
-          engine.routes.routes.routes
+        ::Rails::Engine.subclasses.flat_map.with_object({}) do |engine, hash|
+          next if (eng_routes = engine.routes.routes.routes).none?
+
+          hash["/#{engine.engine_name}"] = eng_routes
         end
       end
+
+      def build_route(engine_name, rails_route)
+        Route.new(
+          "#{engine_name}#{rails_route.path.spec}",
+          rails_route.defaults[:controller],
+          rails_route.defaults[:action]
+        )
+      end
     end
   end
 end