Tested on Unity 2019.3.0f1
This tool provides a simple script editor inside Unity, for those times you just want to make a quick change to your script without opening your IDE.
Instead of the standard readonly preview of your script, you can write there, then save or discard your changes.
Note : This tool only applies to monoscripts, thus script assets, so don't worry, it's not going to alter any of your monobehaviour custom editors !
Inspired by a project from LeonBBlack (a.k.a "Benoît le sang")
Simply download the unity package file in the releases and double click it (or import it in Unity)
Download this repo and place it in your Unity project's Assets folder.
You should now be able to edit a script when you select one from your assets.
This repo is MIT licensed.