39 lines
1.0 KiB
JavaScript
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;
|
|
};
|