Avoid duplicating routes for HEAD requests.

Follow up to rails#15321

Instead of duplicating the routes, we will first match the HEAD request to
HEAD routes. If no match is found, we will then map the HEAD request to
GET routes.

2 files changed, 32 insertions, 1 deletions

diff --git a/actionpack/test/dispatch/request_test.rb b/actionpack/test/dispatch/request_test.rb
index 84bd392fd9..00b80c7357 100644
--- a/actionpack/test/dispatch/request_test.rb
+++ b/actionpack/test/dispatch/request_test.rb
@@ -650,6 +650,18 @@ class RequestMethod < BaseRequestTest
     end
   end
 
+  test "allow request method hacking" do
+    request = stub_request('REQUEST_METHOD' => 'POST')
+
+    assert_equal 'POST', request.request_method
+    assert_equal 'POST', request.env["REQUEST_METHOD"]
+
+    request.request_method = 'GET'
+
+    assert_equal 'GET', request.request_method
+    assert_equal 'GET', request.env["REQUEST_METHOD"]
+  end
+
   test "invalid http method raises exception" do
     assert_raise(ActionController::UnknownHttpMethod) do
       stub_request('REQUEST_METHOD' => 'RANDOM_METHOD').request_method
diff --git a/actionpack/test/journey/router_test.rb b/actionpack/test/journey/router_test.rb
index 2e7e8e1bea..8fc965adf4 100644
--- a/actionpack/test/journey/router_test.rb
+++ b/actionpack/test/journey/router_test.rb
@@ -503,6 +503,25 @@ module ActionDispatch
         assert called
       end
 
+      def test_recognize_head_route
+        path   = Path::Pattern.from_string "/books(/:action(.:format))"
+        app    = Object.new
+        conditions = { request_method: 'HEAD' }
+        @router.routes.add_route(app, path, conditions, {})
+
+        env = rails_env(
+          'PATH_INFO' => '/books/list.rss',
+          'REQUEST_METHOD' => 'HEAD'
+        )
+
+        called = false
+        @router.recognize(env) do |r, params|
+          called = true
+        end
+
+        assert called
+      end
+
       def test_recognize_head_request_as_get_route
         path   = Path::Pattern.from_string "/books(/:action(.:format))"
         app    = Object.new
@@ -561,7 +580,7 @@ module ActionDispatch
       end
 
       def rails_env env, klass = ActionDispatch::Request
-        klass.new env
+        klass.new(rack_env(env))
       end
 
       def rack_env env