analytics/lib/plausible_web/views/error_view.ex

defmodule PlausibleWeb.ErrorView do
  use PlausibleWeb, :view

  def render("500.json", assigns) do
    message = if assigns[:reason] do
      assigns[:reason].message
    else
      "Something went wrong"
    end

    %{
      status: 500,
      message: message
    }
  end

  def render("404.html", assigns) do
    render("error.html", Map.merge(%{
      layout: false,
      status: 404,
      message: "Oops! There's nothing here"
    }, assigns))
  end

  def render("500.html", assigns) do
    render("error.html", Map.merge(%{
      layout: false,
      status: 500,
      message: "Oops! Looks like we're having server issues"
    }, assigns))
  end

  def template_not_found(template, assigns) do
    status = String.trim_trailing(template, ".html")

    render("error.html", Map.merge(%{
      layout: false,
      status: status,
      message: Phoenix.Controller.status_message_from_template(template)
    }, assigns))
  end
end