node/tools/eslint/node_modules/string-width/index.js
Rich Trott 5e952182e7
tools: update to ESLint 4.3.0
PR-URL: https://github.com/nodejs/node/pull/14417
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Teddy Katz <teddy.katz@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Refael Ackermann <refack@gmail.com>
2017-07-27 23:30:39 +02:00

36 lines
649 B
JavaScript

'use strict';
const stripAnsi = require('strip-ansi');
const isFullwidthCodePoint = require('is-fullwidth-code-point');
module.exports = str => {
if (typeof str !== 'string' || str.length === 0) {
return 0;
}
str = stripAnsi(str);
let width = 0;
for (let i = 0; i < str.length; i++) {
const code = str.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;
};