--- /dev/null
+'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;
+};