defmodule ExWaiter.Polling.InvalidResult do
  defexception [:message]

  @impl true
  def exception(result) do
    msg = """

    Expected:
    {:ok, value} or :ok for success
    {:error, value} or :error for failure

    Got:
    #{inspect(result)}

    Examples:

      Returning a tagged tuple ensures that the Project is returned
      from poll/2.

      %Project{name: name} = poll(fn ->
        case Projects.get(1) do
          %Project{} = project -> {:ok, project}
          value -> {:error, value}
        end
      end)
    """

    %__MODULE__{message: msg}
  end
end