jhefreyzz

jhefreyzz

Try learning again Phoenix channels and stumbled upon a dialyzer warning I can’t seem to solve.
My whole channel code below.

  @impl true
  def join("room:lobby", payload, socket) do
    send(self(), :after_join)

    {:ok, assign(socket, current_user: payload)}
  end

  @impl true
  def handle_info(:after_join, socket) do
    {:ok, _} =
      Presence.track(socket, socket.assigns.current_user.id, %{
        nickname: socket.assigns.current_user.nickname,
        online_at: inspect(System.system_time(:second))
      })

    messages = MessageView.render("messages.json", %{messages: Chat.list_messages()})

    push(socket, "presence_state", Presence.list(socket))
    push(socket, "list_messages", messages)

    {:noreply, socket}
  end

  @impl true
  def handle_in("create_message", payload, socket) do
    {:ok, user} = Accounts.get_user!(socket.current_user.id)
    {:ok, message} = Chat.create_message(user, payload)

    message = MessageView.render("message.json", %{message: message})
    broadcast(socket, "message_created", message)
    {:noreply, socket}
  end

Dialyzer warnings:

The inferred type for the 3rd argument is not a
supertype of the expected type for the handle_in/3 callback
in the Phoenix.Channel behaviour.

Success type:
%Phoenix.Socket{:current_user => atom() | %{:id => _, _ => _}, :joined => true, _ => _}

Behaviour callback type:
%Phoenix.Socket{
  :assigns => map(),
  :channel => atom(),
  :channel_pid => pid(),
  :endpoint => atom(),
  :handler => atom(),
  :id => nil | binary(),
  :join_ref => _,
  :joined => boolean(),
  :private => %{},
  :pubsub_server => atom(),
  :ref => _,
  :serializer => atom(),
  :topic => binary(),
  :transport => atom(),
  :transport_pid => pid()
}
Type mismatch for @callback handle_in/3 in Phoenix.Channel behaviour.

Expected type:

  {:noreply,
   %Phoenix.Socket{
     :assigns => map(),
     :channel => atom(),
     :channel_pid => pid(),
     :endpoint => atom(),
     :handler => atom(),
     :id => nil | binary(),
     :join_ref => _,
     :joined => boolean(),
     :private => %{},
     :pubsub_server => atom(),
     :ref => _,
     :serializer => atom(),
     :topic => binary(),
     :transport => atom(),
     :transport_pid => pid()
   }}
  | {:noreply,
     %Phoenix.Socket{
       :assigns => map(),
       :channel => atom(),
       :channel_pid => pid(),
       :endpoint => atom(),
       :handler => atom(),
       :id => nil | binary(),
       :join_ref => _,
       :joined => boolean(),
       :private => %{},
       :pubsub_server => atom(),
       :ref => _,
       :serializer => atom(),
       :topic => binary(),
       :transport => atom(),
       :transport_pid => pid()
     }, :hibernate | timeout()}
  | {:reply, atom() | {atom(), map()},
     %Phoenix.Socket{
       :assigns => map(),
       :channel => atom(),
       :channel_pid => pid(),
       :endpoint => atom(),
       :handler => atom(),
       :id => nil | binary(),
       :join_ref => _,
       :joined => boolean(),
       :private => %{},
       :pubsub_server => atom(),
       :ref => _,
       :serializer => atom(),
       :topic => binary(),
       :transport => atom(),
       :transport_pid => pid()
     }}
  | {:stop, _,
     %Phoenix.Socket{
       :assigns => map(),
       :channel => atom(),
       :channel_pid => pid(),
       :endpoint => atom(),
       :handler => atom(),
       :id => nil | binary(),
       :join_ref => _,
       :joined => boolean(),
       :private => %{},
       :pubsub_server => atom(),
       :ref => _,
       :serializer => atom(),
       :topic => binary(),
       :transport => atom(),
       :transport_pid => pid()
     }}
  | {:stop, _, atom() | {atom(), map()},
     %Phoenix.Socket{
       :assigns => map(),
       :channel => atom(),
       :channel_pid => pid(),
       :endpoint => atom(),
       :handler => atom(),
       :id => nil | binary(),
       :join_ref => _,
       :joined => boolean(),
       :private => %{},
       :pubsub_server => atom(),
       :ref => _,
       :serializer => atom(),
       :topic => binary(),
       :transport => atom(),
       :transport_pid => pid()
     }}


Actual type:

  {:noreply,
   %Phoenix.Socket{:current_user => atom() | %{:id => _, _ => _}, :joined => true, _ => _}}

Showing Posts 1 to 2

Sebb

Sebb

according to your usage dialyzer thinks that socket has a current_user field.

{:ok, user} = Accounts.get_user!(socket.current_user.id) 

current_user is in socket.assigns.

jhefreyzz

jhefreyzz OP

Yeah, I already fixed it a while a go but forgot to update the thread.

— All posts loaded —

Where Next? Top

Trending in Questions Top

RSP87
I’m working on a project that simulates the bumbl example in the programming phoenix book. It acts almost like an email client. We have a...
New
kpanic
Hi everyone, I am toying with the idea of building a “match maker” for giving personal help to people that wants to start coding. I sta...
New
nseaSeb
Hello, I know there is an approach for handling lists that allows for optimized traversal, but I can’t recall the specific method (somet...
New
brecabral
Documentation While reading the Scoped Routes section, I noticed that the documentation currently refers to a problem without explainin...
New
velrest
So my question is quite simple and i have found no conclusive answer on forum, google or AI. Should we use :erlang.float for Integer to ...
New
asweet-confluent
I recently noticed that Elixir’s Logger defaults its primary log level to :debug when no :logger, :level application configuration is pre...
New
apz
I’m new to elixir and just tried to install the elixirLS extension for VScode(ium) and it is throwing some errors that I would like help ...
New

Other Trending Topics Top

GenericJam
Edit: 2026 May 15 - This post is archived. Mob is alive!! Main docs: mob v0.7.11 — Documentation A bit of explanation for the slightly c...
New
JesseHerrick
Hey, I’m Jesse and I’m the main contributor behind Dexter, a full-featured, lightning-fast Elixir LSP optimized for large codebases. It s...
New
mudasobwa
I am happy to introduce the very α version of the new programming language compiled to BEAM. Welcome Cure. It has literally three kille...
New
marciok
Hi there! We created Gust: A task orchestrator inspired by Airflow. For those who have never heard about Aiflow, it’s a Python-based wor...
New
mhanberg
Hi everyone! The first release candidate for the Expert language server project is now available! We’ve published a press release detai...
New
jimsynz
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews