index.js

'use strict'

split.split = split
split.width = width

module.exports = split

function split(text, columns){
	const rows = []
	let rowBuffer = ''
	let rowBufferLength = 0
	let wordBuffer = ''
	let wordBufferLength = 0
	let spillBuffer = ''
	let spillBufferLength = 0

	for (const char of text.normalize()){
		const code = char.codePointAt()

		if (code <= 32) {
			if (spillBufferLength > 0) {
				rows.push(rowBuffer)

				if (wordBufferLength + spillBufferLength === columns || code === 10) {
					rows.push(wordBuffer+spillBuffer)

					rowBuffer = ''
					rowBufferLength = 0
				} else {
					rowBuffer = wordBuffer+spillBuffer+char
					rowBufferLength = wordBufferLength + spillBufferLength + 1
				}

				spillBuffer = ''
				spillBufferLength = 0
			} else {
				if (rowBufferLength + wordBufferLength === columns || code === 10) {
					rows.push(rowBuffer+wordBuffer)

					rowBuffer = ''
					rowBufferLength = 0
				} else {
					rowBuffer += wordBuffer+char
					rowBufferLength += wordBufferLength + 1
				}
			}

			wordBuffer = ''
			wordBufferLength = 0
		} else {
			if (rowBufferLength + wordBufferLength < columns) {
				wordBuffer += char
				wordBufferLength++
			} else if (wordBufferLength + spillBufferLength === columns) {
				rows.push(rowBuffer+wordBuffer)

				rowBuffer = ''
				rowBufferLength = 0

				if (spillBufferLength === columns) {
					rows.push(spillBuffer)

					wordBuffer = char
					wordBufferLength = 1
				} else {
					wordBuffer = spillBuffer+char
					wordBufferLength = spillBufferLength + 1
				}

				spillBuffer = ''
				spillBufferLength = 0
			} else {
				spillBuffer += char
				spillBufferLength++
			}
		}
	}

	if (spillBufferLength > 0) {
		rows.push(rowBuffer, wordBuffer+spillBuffer)
	} else {
		rows.push(rowBuffer+wordBuffer)
	}

	return rows
}

function width(text, max){
	let i = 0
	let u = 0

	for (const char of text.normalize()) {
		if (char === '\n') {
			u = i > u ? i : u
			i = 0
		} else if (++i === max) {
			return max
		}
	}

	return i > u ? i : u
}