function getNumericISOString() {
	// Get string unique to this millisecond
	let isoString = new Date().toISOString();

	// Remove constant characters
	return isoString.replace(/[^0-9]/g, '');
}

function* generateId() {
	let iterator = 0;
	let prevId = null;

	while (true) {
		let newId = getNumericISOString();

		// If id is not unique, increment iterator
		// Else reset iterator to 0
		iterator = newId === prevId ? ++iterator : 0;

		// Save id for comparison
		prevId = newId;

		yield newId += '-' + iterator;
	}
}

const myGen = generateId();

console.log(myGen.next().value);
console.log(myGen.next().value);
console.log(myGen.next().value);
console.log(myGen.next().value);
console.log(myGen.next().value);
console.log(myGen.next().value);
console.log(myGen.next().value);