Phoenix: mix phx.routes no longer reports route collisions

[RobertDeRose]

Environment

• Elixir version (elixir -v):

  elixir -v
  Erlang/OTP 20 [erts-9.0] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]
  
  Elixir 1.5.1
  

• Phoenix version (mix deps):
  file_system 0.1.5 connection 1.0.4 gettext 0.13.1 ranch 1.3.2 poolboy 1.5.1 decimal 1.4.0 poison 3.1.0 db_connection 1.1.2 phoenix_pubsub 1.0.2 cowlib 1.0.2 cowboy 1.1.2 mime 1.1.0 plug 1.4.3 phoenix_html 2.10.4 phoenix 1.3.0 phoenix_live_reload 1.1.0 mariaex 0.8.3 ecto 2.2.0 phoenix_ecto 3.2.3
• NodeJS version (node -v): v8.4.0
• NPM version (npm -v): 5.3.0
• Operating system: macOS 10.12.6

Expected behavior

To get a warning similar to this

warning: this clause cannot match because a previous clause at line 16 always matches

Actual behavior

No Warning is produced when defining conflicting routes:

  scope "/admin", HelloWeb.Admin, as: :admin do
    pipe_through :browser

    resources "/reviews", ReviewController
  end

  scope "/admin", Something, as: :something do
    resources "/reviews", ReviewController
  end

mix phx.routes produces:

mix phx.routes
Compiling 8 files (.ex)
    admin_review_path  GET     /admin/reviews                  HelloWeb.Admin.ReviewController :index
    admin_review_path  GET     /admin/reviews/:id/edit         HelloWeb.Admin.ReviewController :edit
    admin_review_path  GET     /admin/reviews/new              HelloWeb.Admin.ReviewController :new
    admin_review_path  GET     /admin/reviews/:id              HelloWeb.Admin.ReviewController :show
    admin_review_path  POST    /admin/reviews                  HelloWeb.Admin.ReviewController :create
    admin_review_path  PATCH   /admin/reviews/:id              HelloWeb.Admin.ReviewController :update
                       PUT     /admin/reviews/:id              HelloWeb.Admin.ReviewController :update
    admin_review_path  DELETE  /admin/reviews/:id              HelloWeb.Admin.ReviewController :delete
something_review_path  GET     /admin/reviews                  Something.ReviewController :index
something_review_path  GET     /admin/reviews/:id/edit         Something.ReviewController :edit
something_review_path  GET     /admin/reviews/new              Something.ReviewController :new
something_review_path  GET     /admin/reviews/:id              Something.ReviewController :show
something_review_path  POST    /admin/reviews                  Something.ReviewController :create
something_review_path  PATCH   /admin/reviews/:id              Something.ReviewController :update
                       PUT     /admin/reviews/:id              Something.ReviewController :update
something_review_path  DELETE  /admin/reviews/:id              Something.ReviewController :delete

no error or warning are produced

[chrismccord]

the warning will only be produced the first time you compile the module with duplicate routes. Can you modify the router file ($ touch lib/.../router.ex and rerun the command? You should then see the warning.

[PhillippOhlandt]

I saw a warning yesterday on a new project, so it definitely works.

[RobertDeRose]

Yeah, sorry... still not working on my machine. So @PhillippOhlandt is there anything different about my stated versions than yours?

➤ touch lib/hello_web/router.ex
➤ mix phx.routes
Compiling 8 files (.ex)
            page_path  GET     /                               HelloWeb.PageController :index
           hello_path  GET     /hello                          HelloWeb.HelloController :index
           hello_path  GET     /hello/:messenger               HelloWeb.HelloController :show
            user_path  GET     /users                          HelloWeb.UserController :index
            user_path  GET     /users/:id/edit                 HelloWeb.UserController :edit
            user_path  GET     /users/new                      HelloWeb.UserController :new
            user_path  GET     /users/:id                      HelloWeb.UserController :show
            user_path  POST    /users                          HelloWeb.UserController :create
            user_path  PATCH   /users/:id                      HelloWeb.UserController :update
                       PUT     /users/:id                      HelloWeb.UserController :update
            user_path  DELETE  /users/:id                      HelloWeb.UserController :delete
       user_post_path  GET     /users/:user_id/posts           HelloWeb.PostController :index
       user_post_path  GET     /users/:user_id/posts/:id/edit  HelloWeb.PostController :edit
       user_post_path  GET     /users/:user_id/posts/new       HelloWeb.PostController :new
       user_post_path  GET     /users/:user_id/posts/:id       HelloWeb.PostController :show
       user_post_path  POST    /users/:user_id/posts           HelloWeb.PostController :create
       user_post_path  PATCH   /users/:user_id/posts/:id       HelloWeb.PostController :update
                       PUT     /users/:user_id/posts/:id       HelloWeb.PostController :update
       user_post_path  DELETE  /users/:user_id/posts/:id       HelloWeb.PostController :delete
    admin_review_path  GET     /admin/reviews                  HelloWeb.Admin.ReviewController :index
    admin_review_path  GET     /admin/reviews/:id/edit         HelloWeb.Admin.ReviewController :edit
    admin_review_path  GET     /admin/reviews/new              HelloWeb.Admin.ReviewController :new
    admin_review_path  GET     /admin/reviews/:id              HelloWeb.Admin.ReviewController :show
    admin_review_path  POST    /admin/reviews                  HelloWeb.Admin.ReviewController :create
    admin_review_path  PATCH   /admin/reviews/:id              HelloWeb.Admin.ReviewController :update
                       PUT     /admin/reviews/:id              HelloWeb.Admin.ReviewController :update
    admin_review_path  DELETE  /admin/reviews/:id              HelloWeb.Admin.ReviewController :delete
something_review_path  GET     /admin/reviews                  Something.ReviewController :index
something_review_path  GET     /admin/reviews/:id/edit         Something.ReviewController :edit
something_review_path  GET     /admin/reviews/new              Something.ReviewController :new
something_review_path  GET     /admin/reviews/:id              Something.ReviewController :show
something_review_path  POST    /admin/reviews                  Something.ReviewController :create
something_review_path  PATCH   /admin/reviews/:id              Something.ReviewController :update
                       PUT     /admin/reviews/:id              Something.ReviewController :update
something_review_path  DELETE  /admin/reviews/:id              Something.ReviewController :delete
                       *       /jobs                           BackgroundJob.Plug []

clearly there are duplicate routes here, and clearly there is no warning, even after touching the file.

I mean, I noticed this bug when I was following the tutorial and it was telling me about duplicate route warnings and when I did as the tutorial stated, it didn't warn the first or any other time, so I came up with this example to show the issue.

Close it if you like, but it's no longer working. I remember it worked when I tried Phoenix out about a year ago, but never got to do much more than the tutorial, so I started over because it's been so long.

The behavior has changed or something about a fresh install is causing issues, or maybe it's just something with my shell, for all I know. If I knew how to debug it, I would give you more information.

[PhillippOhlandt]

@RobertDeRose Maybe you hit an edge case. I think it would be the best if you could provide an example git repo with the issue so we can try on our machines.

[chrismccord]

Can you include your complete router?

[frankmariette]

I'm also having the same issue as @RobertDeRose. Here is my router which is primarily from following the tutorial.

defmodule HelloWeb.Router do
  use HelloWeb, :router

  pipeline :browser do
    plug :accepts, ["html"]
    plug :fetch_session
    plug :fetch_flash
    plug :protect_from_forgery
    plug :put_secure_browser_headers
  end

  pipeline :api do
    plug :accepts, ["json"]
  end

  scope "/", HelloWeb do
    pipe_through :browser # Use the default browser stack

    get "/", PageController, :index
    get "/hello", HelloController, :index
    get "/hello/:messenger", HelloController, :show
    resources "/reviews", ReviewController
    resources "/users", UserController do
      resources "/posts", PostController
    end

    get "/hello", ByeController, :index
  end

  scope "/", HelloWeb do
    pipe_through :browser

    get "/", PageController, :index
  end

  scope "/admin", HelloWeb.Admin, as: :admin do
    pipe_through :browser

    resources "/reviews", ReviewController
  end
end

[RobertDeRose]

@chrismccord what @frankmariette included is equal to what I had while following the tutorial

[Gazler]

This is potentially an issue related to elixir versions. I'll investigate.

[getschomp]

Hitting this issue:

~/hello
❯ mix compile
Compiling 1 file (.ex)

~/hello
❯ mix phx.routes
Compiling 8 files (.ex)
page_path GET / HelloWeb.PageController :index
root_path GET / HelloWeb.RootController :index
hello_path GET /hello HelloWeb.HelloController :index
hello_path GET /hello/:messenger HelloWeb.HelloController :show

~/hello
❯ mix phoenix.new -v
Phoenix v1.3.0

~/hello
❯ elixir -v
Erlang/OTP 20 [erts-9.1.3] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Elixir 1.5.1

[chrismccord]

This is an issue in Elixir and should be fixed in the next release. You can check the process here https://github.com/elixir-lang/elixir/issues/6637

[getschomp]

@chrismccord should the guides be updated while this is being updated?

[chrismccord]

I believe it only affects Elixir 1.5 and will be fixed in 1.6 so I think we can hold off

[josevalim]

Good news: it is fixed in Elixir master and the v1.5 branch. I plan to release v1.5.3 with a fix this or next week.

[frankmariette]

Thanks @josevalim and @chrismccord for looking into this and getting it fixed.