vrm-no-fs/lib/formats/diplomatic.js

Coerces, validates and prettifies vehicle registration marks (VRMs)

exports.ref = 'diplomatic';
exports.validFrom = 1979;
exports.parse = parse;

const regex = /^(\d{3})(D|X)(\d{3})$/;

function parse(vrm) {
	const match = vrm.match(regex);

	if (!match)
		return null;

	const entity = parseInt(match[1], 10);
	const serial = parseInt(match[3], 10);

	return {
		prettyVrm: match.slice(1).join(' '),

		_extra: {
			entity: entity,
			serial: serial,
		},
	};
}