Allow custom paths to be provided to :websocket and :longpoll (phoeni…

…xframework#3166)

* Allow custom paths to be provided to :websocket and :longpoll

Previously, it was not possible to use a socket with a path that differed from
the key name. For example `:websocket` would always end with `/websocket` and
`:longpoll` would always end with `/longpoll`.

This commit allows a `:path` to be passed into the keyword options, the path
will be used instead of the default if available.

lib/phoenix/endpoint.ex

@@ -777,25 +777,28 @@ defmodule Phoenix.Endpoint do
 
     paths =
       if websocket do
-        triplet = {:websocket, socket, socket_config(websocket, Phoenix.Transports.WebSocket)}
-        [{socket_path(path, :websocket), triplet} | paths]
+        config = socket_config(websocket, Phoenix.Transports.WebSocket)
+        triplet = {:websocket, socket, config}
+        [{socket_path(path, config), triplet} | paths]
       else
         paths
       end
 
     paths =
       if longpoll do
-        plug_init = {endpoint, socket, socket_config(longpoll, Phoenix.Transports.LongPoll)}
-        [{socket_path(path, :longpoll), {:plug, Phoenix.Transports.LongPoll, plug_init}} | paths]
+        config = socket_config(longpoll, Phoenix.Transports.LongPoll)
+        plug_init = {endpoint, socket, config}
+        [{socket_path(path, config), {:plug, Phoenix.Transports.LongPoll, plug_init}} | paths]
       else
         paths
       end
 
     paths
   end
 
-  defp socket_path(path, key) do
-    String.split(path, "/", trim: true) ++ [Atom.to_string(key)]
+  defp socket_path(path, config) do
+    end_path_fragment = Keyword.fetch!(config, :path)
+    String.split(path <> "/" <> end_path_fragment, "/", trim: true)
   end
 
   defp socket_config(true, module), do: module.default_config()
@@ -839,6 +842,9 @@ defmodule Phoenix.Endpoint do
   The configuration below can be given to both `:websocket` and
   `:longpoll` keys:
 
+    * `:path` - the path to use for the transport. Will default
+       to the transport name ("/websocket" or "/longpoll")
+
     * `:serializer` - a list of serializers for messages. See
       `Phoenix.Socket` for more information
 

lib/phoenix/endpoint/cowboy_adapter.ex

@@ -104,10 +104,11 @@ defmodule Phoenix.Endpoint.CowboyAdapter do
 
     paths =
       if websocket do
-        init = {endpoint, socket, socket_config(websocket, Phoenix.Transports.WebSocket)}
+        config = socket_config(websocket, Phoenix.Transports.WebSocket)
+        init = {endpoint, socket, config}
 
         [
-          {socket_path(path, :websocket), Phoenix.Endpoint.CowboyWebSocket,
+          {socket_path(path, config), Phoenix.Endpoint.CowboyWebSocket,
            {Phoenix.Transports.WebSocket, init}}
           | paths
         ]
@@ -117,10 +118,11 @@ defmodule Phoenix.Endpoint.CowboyAdapter do
 
     paths =
       if longpoll do
-        init = {endpoint, socket, socket_config(longpoll, Phoenix.Transports.LongPoll)}
+        config = socket_config(longpoll, Phoenix.Transports.LongPoll)
+        init = {endpoint, socket, config}
 
         [
-          {socket_path(path, :longpoll), Plug.Adapters.Cowboy.Handler,
+          {socket_path(path, config), Plug.Adapters.Cowboy.Handler,
            {Phoenix.Transports.LongPoll, init}}
           | paths
         ]
@@ -130,9 +132,9 @@ defmodule Phoenix.Endpoint.CowboyAdapter do
 
     paths
   end
-
-  defp socket_path(path, key) do
-    parts = String.split(path, "/", trim: true) ++ [Atom.to_string(key)]
+  defp socket_path(path, config) do
+    end_path_fragment = Keyword.fetch!(config, :path)
+    parts = String.split(path <> "/" <> end_path_fragment, "/", trim: true)
     "/" <> Path.join(parts)
   end
 

lib/phoenix/transports/long_poll.ex

@@ -8,6 +8,7 @@ defmodule Phoenix.Transports.LongPoll do
   def default_config() do
     [
       window_ms: 10_000,
+      path: "/longpoll",
       pubsub_timeout_ms: 2_000,
       serializer: [{V1.JSONSerializer, "~> 1.0.0"}, {V2.JSONSerializer, "~> 2.0.0"}],
       transport_log: false,

lib/phoenix/transports/websocket.ex

@@ -4,6 +4,7 @@ defmodule Phoenix.Transports.WebSocket do
 
   def default_config() do
     [
+      path: "/websocket",
       serializer: [{V1.JSONSerializer, "~> 1.0.0"}, {V2.JSONSerializer, "~> 2.0.0"}],
       timeout: 60_000,
       transport_log: false,

test/phoenix/integration/websocket_socket_test.exs

@@ -63,6 +63,10 @@ defmodule Phoenix.Integration.WebSocketTest do
     socket "/ws", UserSocket,
       websocket: [check_origin: ["//example.com"], timeout: 200],
       custom: :value
+
+    socket "/custom/some_path", UserSocket,
+      websocket: [path: "nested/path", check_origin: ["//example.com"], timeout: 200],
+      custom: :value
   end
 
   setup_all do
@@ -91,4 +95,9 @@ defmodule Phoenix.Integration.WebSocketTest do
     WebsocketClient.send_message(client, "ping")
     assert_receive {:text, "pong"}
   end
+
+  test "allows a custom path" do
+    path = "ws://127.0.0.1:#{@port}/custom/some_path/nested/path"
+    assert {:ok, client} = WebsocketClient.start_link(self(), "#{path}?key=value", :noop)
+  end
 end