A module (not a plug) for debugging in development.

This module is commonly used within a Plug.Builder or a Plug.Router and it wraps the call/2 function.

Notice Plug.Debugger does not catch errors, as errors should still propagate so that the Elixir process finishes with the proper reason. This module does not perform any logging either, as all logging is done by the web server handler.

Note: If this module is used with Plug.ErrorHandler, only one of them will effectively handle errors. For this reason, it is recommended that Plug.Debugger is used before Plug.ErrorHandler and only in particular environments, like :dev.

Examples

defmodule MyApp do
  use Plug.Builder

  if Mix.env == :dev do
    use Plug.Debugger, otp_app: :my_app
  end

  plug :boom

  def boom(conn, _) do
    # Error raised here will be caught and displayed in a debug page
    # complete with a stacktrace and other helpful info.
    raise "oops"
  end
end

Options

• :otp_app - same as in wrap/3

Links to the text editor

If a PLUG_EDITOR environment variable is set, Plug.Debugger will use it to generate links to your text editor. The variable should be set with __FILE__ and __LINE__ placeholders which will be correctly replaced. For example (with the TextMate editor):

txmt://open/?url=file://__FILE__&line=__LINE__