blob: 33c9d6c06f7a592e60551578ef6e6a4290bb389e [file] [log] [blame]
'use strict';
const stripAnsi = require('strip-ansi');
const isFullwidthCodePoint = require('is-fullwidth-code-point');
const emojiRegex = require('emoji-regex')();
module.exports = input => {
input = input.replace(emojiRegex, ' ');
if (typeof input !== 'string' || input.length === 0) {
return 0;
}
input = stripAnsi(input);
let width = 0;
for (let i = 0; i < input.length; i++) {
const code = input.codePointAt(i);
// Ignore control characters
if (code <= 0x1F || (code >= 0x7F && code <= 0x9F)) {
continue;
}
// Ignore combining characters
if (code >= 0x300 && code <= 0x36F) {
continue;
}
// Surrogates
if (code > 0xFFFF) {
i++;
}
width += isFullwidthCodePoint(code) ? 2 : 1;
}
return width;
};