pad.js 582 Bytes
"use strict";

var toInteger = require("../../number/to-integer")
  , value     = require("../../object/valid-value")
  , repeat    = require("./repeat")
  , abs       = Math.abs
  , max       = Math.max;

module.exports = function (fill/*, length*/) {
	var self = String(value(this)), sLength = self.length, length = arguments[1];

	length = isNaN(length) ? 1 : toInteger(length);
	fill = repeat.call(String(fill), abs(length));
	if (length >= 0) return fill.slice(0, max(0, length - sLength)) + self;
	return self + (sLength + length >= 0 ? "" : fill.slice(length + sLength));
};