1'use strict'; 2const stripAnsi = require('strip-ansi'); 3const isFullwidthCodePoint = require('is-fullwidth-code-point'); 4const emojiRegex = require('emoji-regex')(); 5 6module.exports = input => { 7 input = input.replace(emojiRegex, ' '); 8 9 if (typeof input !== 'string' || input.length === 0) { 10 return 0; 11 } 12 13 input = stripAnsi(input); 14 15 let width = 0; 16 17 for (let i = 0; i < input.length; i++) { 18 const code = input.codePointAt(i); 19 20 // Ignore control characters 21 if (code <= 0x1F || (code >= 0x7F && code <= 0x9F)) { 22 continue; 23 } 24 25 // Ignore combining characters 26 if (code >= 0x300 && code <= 0x36F) { 27 continue; 28 } 29 30 // Surrogates 31 if (code > 0xFFFF) { 32 i++; 33 } 34 35 width += isFullwidthCodePoint(code) ? 2 : 1; 36 } 37 38 return width; 39}; 40