IOTConnect-Web/node_modules/es5-ext/string/random.js
2024-05-09 09:49:52 +08:00

39 lines
1.0 KiB
JavaScript

"use strict";
var isValue = require("../object/is-value")
, toNaturalNumber = require("../number/to-pos-integer");
var generated = Object.create(null), random = Math.random, uniqTryLimit = 100;
var getChunk = function () { return random().toString(36).slice(2); };
var getString = function (/* length */) {
var str = getChunk(), length = arguments[0];
if (!isValue(length)) return str;
while (str.length < length) str += getChunk();
return str.slice(0, length);
};
module.exports = function (/* options */) {
var options = Object(arguments[0]), length = options.length, isUnique = options.isUnique;
if (isValue(length)) length = toNaturalNumber(length);
var str = getString(length);
if (isUnique) {
var count = 0;
while (generated[str]) {
if (++count === uniqTryLimit) {
throw new Error(
"Cannot generate random string.\n" +
"String.random is not designed to effectively generate many short and " +
"unique random strings"
);
}
str = getString(length);
}
generated[str] = true;
}
return str;
};