Use env['action_dispatch.routes'] to determine if we should generate prefix or not.

This technique is here to allow using routes from Engine in Application
and vice versa. When using Engine routes inside Application it should
generate prefix based on mount point. When using Engine routes inside
Engine it should use env['SCRIPT_NAME']. In any other case it should
generate prefix as env should not be even available.

2 files changed, 103 insertions, 1 deletions

diff --git a/actionpack/test/controller/routing_test.rb b/actionpack/test/controller/routing_test.rb
index a8c74a6064..1f14607c31 100644
--- a/actionpack/test/controller/routing_test.rb
+++ b/actionpack/test/controller/routing_test.rb
@@ -251,7 +251,7 @@ class LegacyRouteSetTests < Test::Unit::TestCase
       map.pages 'pages', :controller => 'content', :action => 'show_page', :host => 'foo.com'
     end
     x = setup_for_named_route
-    x.expects(:url_for).with(:host => 'foo.com', :only_path => false, :controller => 'content', :action => 'show_page', :use_route => :pages).once
+    x.expects(:url_for).with(:host => 'foo.com', :only_path => false, :controller => 'content', :action => 'show_page', :use_route => :pages, :router => rs).once
     x.send(:pages_url)
   end
 
diff --git a/actionpack/test/dispatch/prefix_generation_test.rb b/actionpack/test/dispatch/prefix_generation_test.rb
new file mode 100644
index 0000000000..95d5c1c366
--- /dev/null
+++ b/actionpack/test/dispatch/prefix_generation_test.rb
@@ -0,0 +1,102 @@
+require 'abstract_unit'
+
+module TestGenerationPrefix
+  class WithMountedEngine < ActionDispatch::IntegrationTest
+    class BlogEngine
+      def self.routes
+        @routes ||= begin
+          routes = ActionDispatch::Routing::RouteSet.new
+          routes.draw do
+            match "/posts/:id", :to => "inside_engine_generating#index", :as => :post
+          end
+
+          routes
+        end
+      end
+
+      def self.call(env)
+        env['action_dispatch.routes'] = routes
+        routes.call(env)
+      end
+    end
+
+    class RailsApplication
+      def self.routes
+        @routes ||= begin
+          routes = ActionDispatch::Routing::RouteSet.new
+          routes.draw do
+            scope "/:omg", :omg => "awesome" do
+              mount BlogEngine => "/blog"
+            end
+            match "/generate", :to => "outside_engine_generating#index"
+          end
+
+          routes
+        end
+      end
+
+      def self.call(env)
+        env['action_dispatch.routes'] = routes
+        routes.call(env)
+      end
+    end
+
+    class ::InsideEngineGeneratingController < ActionController::Base
+      include BlogEngine.routes.url_helpers
+      def index
+        render :text => post_path(:id => params[:id])
+      end
+    end
+
+    class ::OutsideEngineGeneratingController < ActionController::Base
+      include BlogEngine.routes.url_helpers
+      def index
+        render :text => post_path(:id => 1)
+      end
+    end
+
+    class Foo
+      include ActionDispatch::Routing::UrlFor
+      include BlogEngine.routes.url_helpers
+
+      def foo
+        post_path(42)
+      end
+    end
+
+
+    RailsApplication.routes # force draw
+    include BlogEngine.routes.url_helpers
+
+    test "generating URL with prefix" do
+      assert_equal "/awesome/blog/posts/1", post_path(:id => 1)
+    end
+
+    test "use SCRIPT_NAME inside the engine" do
+      env = Rack::MockRequest.env_for("/posts/1")
+      env["SCRIPT_NAME"] = "/pure-awesomness/blog"
+      response = ActionDispatch::Response.new(*BlogEngine.call(env))
+      assert_equal "/pure-awesomness/blog/posts/1", response.body
+    end
+
+    test "prepend prefix outside the engine" do
+      env = Rack::MockRequest.env_for("/generate")
+      env["SCRIPT_NAME"] = "/something" # it could be set by passenger
+      response = ActionDispatch::Response.new(*RailsApplication.call(env))
+      assert_equal "/something/awesome/blog/posts/1", response.body
+    end
+
+    test "generating urls with options for both prefix and named_route" do
+      assert_equal "/pure-awesomness/blog/posts/3", post_path(:id => 3, :omg => "pure-awesomness")
+    end
+
+    test "generating urls with url_for should prepend the prefix" do
+      path = BlogEngine.routes.url_for(:omg => 'omg', :controller => "inside_engine_generating", :action => "index", :id => 1, :only_path => true)
+      assert_equal "/omg/blog/posts/1", path
+    end
+
+    test "generating urls from a regular class" do
+      assert_equal "/awesome/blog/posts/42", Foo.new.foo
+    end
+  end
+end