display mountable engine routes on RoutingError.

4 files changed, 46 insertions, 11 deletions

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 3e8441343f..8a9cd2d8ce 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -560,7 +560,9 @@
 
     *Carlos Galdino + Rafael Mendonça França*
 
-*   Show routes in exception page while debugging a `RoutingError` in development. *Richard Schneeman and Mattt Thompson*
+*   Show routes in exception page while debugging a `RoutingError` in development.
+
+    *Richard Schneeman + Mattt Thompson + Yves Senn*
 
 *   Add `ActionController::Flash.add_flash_types` method to allow people to register their own flash types. e.g.:
 
diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index ac8f6af7fe..5c50f9ec6a 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -2,7 +2,6 @@ require 'action_dispatch/http/request'
 require 'action_dispatch/middleware/exception_wrapper'
 require 'action_dispatch/routing/inspector'
 
-
 module ActionDispatch
   # This middleware is responsible for logging exceptions and
   # showing a debugging page in case the request is local.
@@ -42,12 +41,11 @@ module ActionDispatch
           :application_trace => wrapper.application_trace,
           :framework_trace => wrapper.framework_trace,
           :full_trace => wrapper.full_trace,
-          :routes => formatted_routes(exception),
+          :routes_inspector => routes_inspector(exception),
           :source_extract => wrapper.source_extract,
           :line_number => wrapper.line_number,
           :file => wrapper.file
         )
-
         file = "rescues/#{wrapper.rescue_template}"
         body = template.render(:template => file, :layout => 'rescues/layout')
         render(wrapper.status_code, body)
@@ -85,11 +83,28 @@ module ActionDispatch
       @stderr_logger ||= ActiveSupport::Logger.new($stderr)
     end
 
-    def formatted_routes(exception)
+    def routes_inspector(exception)
       return false unless @routes_app.respond_to?(:routes)
       if exception.is_a?(ActionController::RoutingError) || exception.is_a?(ActionView::Template::Error)
-        inspector = ActionDispatch::Routing::RoutesInspector.new
-        inspector.collect_routes(@routes_app.routes.routes)
+        ActionDispatch::Routing::RoutesInspector.new(@routes_app.routes.routes)
+      end
+    end
+
+    class TableRoutesFormatter
+      def initialize(view)
+        @view = view
+        @buffer = []
+      end
+
+      def section(type, title, routes)
+        @buffer << %(<tr><th colspan="4">#{title}</th></tr>)
+        @buffer << @view.render(partial: "routes/route", collection: routes)
+      end
+
+      def result
+        @view.raw @view.render(layout: "routes/route_wrapper") {
+          @view.raw @buffer.join("\n")
+        }
       end
     end
   end
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/routing_error.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/routing_error.erb
index 77804a8cbb..9463da520b 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/routing_error.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/routing_error.erb
@@ -15,6 +15,7 @@
   <% end %>
   <%= render template: "rescues/_trace" %>
 
+<% if @routes_inspector %>
   <h2>
     Routes
   </h2>
@@ -23,6 +24,5 @@
     Routes match in priority from top to bottom
   </p>
 
-<%= render layout: "routes/route_wrapper" do %>
-  <%= render partial: "routes/route", collection: @routes %>
+  <%= @routes_inspector.format(ActionDispatch::DebugExceptions::TableRoutesFormatter.new(self)) %>
 <% end %>
diff --git a/actionpack/test/dispatch/debug_exceptions_test.rb b/actionpack/test/dispatch/debug_exceptions_test.rb
index 39e791b4f4..1319eba9ac 100644
--- a/actionpack/test/dispatch/debug_exceptions_test.rb
+++ b/actionpack/test/dispatch/debug_exceptions_test.rb
@@ -45,8 +45,17 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
     end
   end
 
-  ProductionApp  = ActionDispatch::DebugExceptions.new(Boomer.new(false))
-  DevelopmentApp = ActionDispatch::DebugExceptions.new(Boomer.new(true))
+  def setup
+    app = ActiveSupport::OrderedOptions.new
+    app.config = ActiveSupport::OrderedOptions.new
+    app.config.assets = ActiveSupport::OrderedOptions.new
+    app.config.assets.prefix = '/sprockets'
+    Rails.stubs(:application).returns(app)
+  end
+
+  RoutesApp = Struct.new(:routes).new(SharedTestRoutes)
+  ProductionApp  = ActionDispatch::DebugExceptions.new(Boomer.new(false), RoutesApp)
+  DevelopmentApp = ActionDispatch::DebugExceptions.new(Boomer.new(true), RoutesApp)
 
   test 'skip diagnosis if not showing detailed exceptions' do
     @app = ProductionApp
@@ -78,6 +87,15 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
     assert boomer.closed, "Expected to close the response body"
   end
 
+  test 'displays routes in a table when a RoutingError occurs' do
+    @app = DevelopmentApp
+    get "/pass", {}, {'action_dispatch.show_exceptions' => true}
+    routing_table = body[/route_table.*<.table>/m]
+    assert_match '/:controller(/:action)(.:format)', routing_table
+    assert_match ':controller#:action', routing_table
+    assert_no_match '&lt;|&gt;', routing_table, "there should not be escaped html in the output"
+  end
+
   test "rescue with diagnostics message" do
     @app = DevelopmentApp