Split String

test.js

function chunkString(str, splitSize = 50) {
const maxChunkedPart = 9999999999999999;
if (typeof str !== 'string') {
    throw "str must be a string";
}

if (str.length <= splitSize) {
	return str;
}
const trimedString = str.replace(/\s+/g," ");

const chunkedString = trimedString.match(new RegExp('.{1,' + splitSize + '}', 'g')) // split into limit 50 character.


const result = [];
const splitBySpace = trimedString.split(" ");
splitBySpace.forEach((word) => {
	if (word.length >= 50) {
		throw "invalid string";
	}
});
let reservedString = null;

const resultArrayLength = chunkedString.length;



for (let i = 1; i <= resultArrayLength; i += 1) {
	result.push(i.toString() + "/" + resultArrayLength.toString());
	if (reservedString !== null) {
			result[i-1] += ` ${reservedString}`;
		}
	while (splitBySpace.length > 0) {
		const word = splitBySpace.shift(); 
		if (word) {
			const newWord = result[i-1] + ` ${word}`;
			if (newWord.length <= splitSize) {
				result[i-1] = result[i-1] + ` ${word}`;
				reservedString = null;
			} else {
				reservedString = word;
				break;
			}
		}
	}
	
	
}
return result;
}
const happyCase = chunkString("I can't believe Tweeter now supports chunking my messages, so I don't have to do it myself.", 50);
const badCase = chunkString("I can't believe Tweeter now supports chunking my messages, so I don't have to do it myself. ha", 50);
console.log(badCase);
const objectCase = chunkString({"obj": 1}, 10);
const stringShorterThanLimit = chunkString("I can't believe Tweeter now supports");
const whiteSpaceTrimmed = chunkString("I can't         believe Tweeter         now supports chunking my messages, so I don't have to do it myself.     ", 50);
const invalidWords = chunkString("I can'tdfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffieve Tweeter         now supports chunking my messages, so I don't have to do it myself.     ", 50);