UPGRADING

git clone https://github.com/beautify-web/js-beautify.git
cd js-beautify
Retrieve the latest tag with

git describe --tags `git rev-list --tags --max-count=1`

Move to the latest tag git checkout ${latestTag} (${latestTag} should be replaced with what was printed at step 3).
npm install
npx webpack
Copy js/lib/beautify.js to devtools/shared/jsbeautify/src/beautify-js.js
Copy js/lib/beautify-html.js to devtools/shared/jsbeautify/src/beautify-html.js
Replace the following line at the bottom of the file:

var js_beautify = require('./beautify.js');

with (changing beautify.js into beautify-js.js):

var js_beautify = require('./beautify-js.js');

Copy js/lib/beautify-css.js to devtools/shared/jsbeautify/src/beautify-css.js