jsbarcode-fixed/src/barcodes/MSI/checksums.js

JsBarcode is a customizable barcode generator with support for multiple barcode formats.

export function mod10(number){
	var sum = 0;
	for(var i = 0; i < number.length; i++){
		var n = parseInt(number[i]);
		if((i + number.length) % 2 === 0){
			sum += n;
		}
		else{
			sum += (n * 2) % 10 + Math.floor((n * 2) / 10);
		}
	}
	return (10 - (sum % 10)) % 10;
}

export function mod11(number){
	var sum = 0;
	var weights = [2, 3, 4, 5, 6, 7];
	for(var i = 0; i < number.length; i++){
		var n = parseInt(number[number.length - 1 - i]);
		sum += weights[i % weights.length] * n;
	}
	return (11 - (sum % 11)) % 11;
}