60 lines
1.3 KiB
JavaScript
60 lines
1.3 KiB
JavaScript
|
'use strict';
|
||
|
|
const isFullwidthCodePoint = require('is-fullwidth-code-point');
|
||
|
|
const astralRegex = require('astral-regex');
|
||
|
|
const ansiStyles = require('ansi-styles');
|
||
|
|
|
||
|
|
const ESCAPES = [
|
||
|
|
'\u001B',
|
||
|
|
'\u009B'
|
||
|
|
];
|
||
|
|
|
||
|
|
const END_CODE = 39;
|
||
|
|
|
||
|
|
const wrapAnsi = code => `${ESCAPES[0]}[${code}m`;
|
||
|
|
|
||
|
|
module.exports = (str, begin, end) => {
|
||
|
|
const arr = [...str.normalize()];
|
||
|
|
|
||
|
|
end = typeof end === 'number' ? end : arr.length;
|
||
|
|
|
||
|
|
let insideEscape = false;
|
||
|
|
let escapeCode = null;
|
||
|
|
let visible = 0;
|
||
|
|
let output = '';
|
||
|
|
|
||
|
|
for (const [i, x] of arr.entries()) {
|
||
|
|
let leftEscape = false;
|
||
|
|
|
||
|
|
if (ESCAPES.includes(x)) {
|
||
|
|
insideEscape = true;
|
||
|
|
const code = /\d[^m]*/.exec(str.slice(i, i + 18));
|
||
|
|
escapeCode = code === END_CODE ? null : code;
|
||
|
|
} else if (insideEscape && x === 'm') {
|
||
|
|
insideEscape = false;
|
||
|
|
leftEscape = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!insideEscape && !leftEscape) {
|
||
|
|
++visible;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!astralRegex({exact: true}).test(x) && isFullwidthCodePoint(x.codePointAt())) {
|
||
|
|
++visible;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (visible > begin && visible <= end) {
|
||
|
|
output += x;
|
||
|
|
} else if (visible === begin && !insideEscape && escapeCode !== null && escapeCode !== END_CODE) {
|
||
|
|
output += wrapAnsi(escapeCode);
|
||
|
|
} else if (visible >= end) {
|
||
|
|
if (escapeCode !== null) {
|
||
|
|
output += wrapAnsi(ansiStyles.codes.get(parseInt(escapeCode, 10)) || END_CODE);
|
||
|
|
}
|
||
|
|
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return output;
|
||
|
|
};
|