Just created a very simple library that allows you to have syntax highlighting in the Phoenix debugger. Code here: GitHub - tmbb/phoenix_with_pretty_debugger: Add syntax highlighting to the Plug debugger used by Phoenix · GitHub

PhoenixWithPrettyDebugger

Adds support for syntax highlighting in the Phoenix debugger.

To use, replace the following line in your application’s endpoint:

use Phoenix.Endpoint, otp_app: :your_app

by the this line:

use PhoenixWithPrettyDebugger.Endpoint, otp_app: :your_app

No other changes are needed.

Happy hacking with a prettier debugging experience!

The highlighter supports elixir and erlang by default (so it can even highlight code in the cowboy modules). Internaly this project uses the makeup syntax highlighting library and you can add support for other languages by importing the appropriate lexers.

Example output:

Highlighting Elixir:

highlighted-elixir1282×1030 70.5 KB

Highlighting Erlang:

highlighted-erlang1282×1030 75.9 KB

Is this safe?!

This library simply defines an alternative to the default Phoenix.Endpoint module which is actually API compatible. We reuse as much functionality from that module as possible and only redefine the parts we need to add our new debugger. Becuase the debugger is only used in :dev and never in :prod