Dialyzer and defoverridable: Warning if overrided function does not return all possible values

Questions & Help Questions
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2

Imho it is: Why duplicate the delegate functionality if it’s not implementation dependant:

defmodule Handler do
  def delegate(impl, args) do
    case impl.handle(args) do
      :ok ->
        :ok

      {:error, reason} = result ->
        do_something(result)
        :ok
    end
  end

  defp do_something(_) do
    # Log stuff or whatever
  end

  @callback handle(any) :: :ok | {:error, any}
  @optional_callbacks handle: 1
end

defmodule Implementation do
  @behaviour Handler

  @impl true
  def handle(_) do
    :ok
  end
end

defmodule OtherImplementation do
  @behaviour Handler

  @impl true
  def handle(_) do
    {:error, "something went wrong"}
  end
end