The bundle has a composer.json file, so you can simply add it to your requirements:
require: "exercise/htmlpurifier-bundle": "1.0.*@dev"
If you don't need the bundle. you can just add the HTMLPurifier package:
require: "ezyang/htmlpurifier": "dev-master"
If you see a composer.json
file in a repository on Github, you can just search on Packagist: