Optional Behaviour for creating error handlers for Guardian.Plug.Pipeline.

Error handler

When using plugs, you'll need to specify an error handler module.

The error_handler module requires an auth_error function that receives the conn, the reason tuple and the options.

defmodule MyApp.AuthErrorHandler do
  @behaviour Guardian.Plug.ErrorHandler

  @impl Guardian.Plug.ErrorHandler
  def auth_error(conn, {type, reason}, opts) do
    ...
  end
end

By default, Guardian will emit types of:

• :unauthorized
• :invalid_token
• :already_authenticated
• :no_resource_found