Soundcheck.Check.Warning.LiveViewCallbackInComponent (soundcheck v0.1.0)

Basics

This check has a base priority of high and works with any version of Elixir.

Explanation

Flags LiveView callbacks defined in a LiveComponent: mount/3, handle_params/3, handle_info/2, handle_call/3, handle_cast/2, and terminate/2. A LiveComponent runs in its parent LiveView's process and LiveView never calls these on it, so the code is dead. send(self(), msg) from a component reaches the parent's handle_info/2, not the component's.

Before:

# in a LiveComponent
def handle_info({:saved, post}, socket), do: {:noreply, assign(socket, :post, post)}

After:

# in the parent LiveView
def handle_info({:saved, post}, socket) do
  send_update(MyAppWeb.PostComponent, id: post.id, post: post)
  {:noreply, socket}
end

A function another module calls on the component, such as a parent that delegates handle_info/2 to it, does not count as dead. The compiler already warns when the function carries @impl true.

Confidence: high. Tier: syntactic (works without compiling).

Check-Specific Parameters

Use the following parameters to configure this check:

:excluded_paths

Paths to skip (atoms, binaries as path segments, or regexes).

This parameter defaults to [~r/\/test\//, "test"].

:strict

Unused.

This parameter defaults to false.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.