Quick js script to convert vtt format data to srt

vtt2srt.js

function vtt2srt(raw) {
	if (raw.substr(0,6) !== 'WEBVTT')
		throw new TypeError('data does not look like webvtt');

	var vtt = raw.replace('\r', '').trim();
	var data = '1\n' + vtt.substr(vtt.indexOf('\n\n')+2); // get past the blank line and get the 1 started

	var i = 1; // iterate the sub numbers
	return data.replace(/\n\n/g, str => '\n\n' + (++i) + '\n'); // add the numbers at new lines
}

module.exports = vtt2srt;
// fs.writeFileSync('./out.en.srt', vtt2srt(fs.readFileSync('./lw.en.vtt', 'utf8')))