Handle params in forward, closes #3428

lib/phoenix/router.ex

@@ -337,9 +337,9 @@ defmodule Phoenix.Router do
     {matches, _} = Enum.map_reduce(routes_with_exprs, %{}, &build_match/2)
 
     checks =
-      for {%{line: line}, %{dispatch: {plug, params}}} <- routes_with_exprs, into: %{} do
+      for {%{line: line, plug: plug, plug_opts: plug_opts}, _} <- routes_with_exprs, into: %{} do
         quote line: line do
-          {unquote(plug).init(unquote(params)), true}
+          {unquote(plug).init(unquote(Macro.escape(plug_opts))), []}
         end
       end
 
@@ -823,12 +823,9 @@ defmodule Phoenix.Router do
   The router pipelines will be invoked prior to forwarding the
   connection.
 
-  The forwarded plug will be initialized at compile time.
-
-  Note, however, that we don't advise forwarding to another
-  endpoint. The reason is that plugs defined by your app
-  and the forwarded endpoint would be invoked twice, which
-  may lead to errors.
+  However, we don't advise forwarding to another endpoint.
+  The reason is that plugs defined by your app and the forwarded
+  endpoint would be invoked twice, which may lead to errors.
 
   ## Examples
 

test/phoenix/router/forward_test.exs

@@ -14,6 +14,7 @@ defmodule Phoenix.Router.ForwardTest do
 
     def index(conn, _params), do: text(conn, "admin index")
     def stats(conn, _params), do: text(conn, "stats")
+    def params(conn, params), do: text(conn, inspect(params))
     def api_users(conn, _params), do: text(conn, "api users")
     def api_root(conn, _params), do: text(conn, "api root")
     defp assign_fwd_script(conn, _), do: assign(conn, :fwd_script, conn.script_name)
@@ -56,8 +57,9 @@ defmodule Phoenix.Router.ForwardTest do
       forward "/admin", AdminDashboard
       forward "/init", InitPlug
       forward "/assign/opts", AssignOptsPlug, %{foo: "bar"}
-      scope "/internal" do
-        forward "/api/v1", ApiRouter
+
+      scope "/params/:param" do
+        forward "/", Controller, :params
       end
     end
   end
@@ -114,9 +116,9 @@ defmodule Phoenix.Router.ForwardTest do
     conn = call(Router, :get, "admin")
     assert conn.private[Router] == {[], %{
       Phoenix.Router.ForwardTest.AdminDashboard => ["admin"],
-      Phoenix.Router.ForwardTest.ApiRouter => ["api", "v1"],
       Phoenix.Router.ForwardTest.InitPlug => ["init"],
-      Phoenix.Router.ForwardTest.AssignOptsPlug => ["assign", "opts"]
+      Phoenix.Router.ForwardTest.AssignOptsPlug => ["assign", "opts"],
+      Phoenix.Router.ForwardTest.Controller => []
     }}
     assert conn.private[AdminDashboard] ==
       {["admin"], %{Phoenix.Router.ForwardTest.ApiRouter => ["api-admin"]}}
@@ -148,6 +150,10 @@ defmodule Phoenix.Router.ForwardTest do
     assert call(Router, :get, "assign/opts").assigns.opts == %{foo: "bar"}
   end
 
+  test "forward can handle params" do
+    assert call(Router, :get, "params/hello_world").resp_body =~ ~s["param" => "hello_world"]
+  end
+
   test "forward with scoped alias" do
     conn = call(ApiRouter, :get, "health")
     assert conn.resp_body == "health"