1 var repeat = require('./repeat'),
2 stringSize = require('./_stringSize'),
3 stringToArray = require('./_stringToArray'),
4 toInteger = require('./toInteger');
6 /** Used to compose unicode character classes. */
7 var rsAstralRange = '\\ud800-\\udfff',
8 rsComboMarksRange = '\\u0300-\\u036f\\ufe20-\\ufe23',
9 rsComboSymbolsRange = '\\u20d0-\\u20f0',
10 rsVarRange = '\\ufe0e\\ufe0f';
12 /** Used to compose unicode capture groups. */
13 var rsZWJ = '\\u200d';
15 /** Used to detect strings with [zero-width joiners or code points from the astral planes](http://eev.ee/blog/2015/09/12/dark-corners-of-unicode/). */
16 var reHasComplexSymbol = RegExp('[' + rsZWJ + rsAstralRange + rsComboMarksRange + rsComboSymbolsRange + rsVarRange + ']');
18 /* Built-in method references for those with the same name as other `lodash` methods. */
19 var nativeCeil = Math.ceil;
22 * Creates the padding for `string` based on `length`. The `chars` string
23 * is truncated if the number of characters exceeds `length`.
26 * @param {string} string The string to create padding for.
27 * @param {number} [length=0] The padding length.
28 * @param {string} [chars=' '] The string used as padding.
29 * @returns {string} Returns the padding for `string`.
31 function createPadding(string, length, chars) {
32 length = toInteger(length);
34 var strLength = stringSize(string);
35 if (!length || strLength >= length) {
38 var padLength = length - strLength;
39 chars = chars === undefined ? ' ' : (chars + '');
41 var result = repeat(chars, nativeCeil(padLength / stringSize(chars)));
42 return reHasComplexSymbol.test(chars)
43 ? stringToArray(result).slice(0, padLength).join('')
44 : result.slice(0, padLength);
47 module.exports = createPadding;