Fired before a file will be added.
Event::on(
\bitboxde\minifier\services\View::class,
\bitboxde\minifier\services\View::EVENT_BEFORE_MINIFY_FILE,
function(\bitboxde\minifier\events\ViewEvent $event) {
$event->type;
$event->filePath;
$event->output;
});
See Integrate a CSS preprocessor (Sass / Less) for an example.