Messup

1. Overview
2. Installation
3. Usage
4. Methods
   1. .number(min, max, hideWarning)
   2. .numberByLength(length, hideWarning)
   3. .string(length, customChars)
   4. .base62(length)
   5. .base64(bytes)
   6. .hex(bytes, useUpperCase)
   7. .bytes(bytes, encoding)

Overview

Messup is a JavaScript tool that can be used in both Node and browsers to generate random string or number, even cryptographically.

Method	Return Type	Crypto
.number	number	No
.numberByLength	number	No
.string	string	No
.base62	string	No
.base64	string	No
.hex	string	No
.bytes	string | Buffer | Uint8Array	Yes

Support

Node

All stable Node versions.

Browser

Browser	Version (>=)
Chrome	11
Edge	12
Firefox	26
Internet Explorer	11
Opera	15
Safari	6.1
Android Webview	Yes
Chrome for Android	18
Firefox for Android	26
Opera for Android	14
Safari on iOS	6.1
Samsung Internet	Yes

Installation

npm install --save messup

Usage

Messup is not a class or constructor. It is only an object containing methods.

Node or Browser (with framework):

// Require the package
const Messup = require('messup');

// Require and destruct the package
const { number, hex, base64 } = require('messup');

/* OR */

// Import the package
import Messup from 'messup'

// Import and destruct the package
import { string, base62, bytes } from 'messup'

Browser (without framework):

<script src="path/to/messup/index.min.js"></script>
<script>
<!-- Package will expose `Messup` to `window` -->
Messup.base62(...);
Messup.string(...);
</script>

Methods

All methods are synchronous.

.number(min, max, hideWarning)

Randomly generates a number from the specified range. Both min and max are inclusive in the generation.

As JavaScript numbers are represented in IEEE-754 binary64 format, numbers with more than 15 digits cannot be precisely computed. A warning will be printed to console when this happens.

This method is not cryptographically secure.

Parameters

Parameter	Type	Default	Description
min	Number	0	Mininum possible number.
max	Number	1	Maximum possible number.
hideWarning	Boolean	-	Set to true to hide large number warning.

Return value

A random number from min to max.

.numberByLength(length, hideWarning)

Randomly generates a number by specifying the result length.

As JavaScript numbers are represented in IEEE-754 binary64 format, numbers with more than 15 digits cannot be precisely computed. A warning will be printed to console when this happens.

This method is not cryptographically secure.

Parameters

Parameter	Type	Default	Description
length	Number	-	Specify the expected length to be generated.
hideWarning	Boolean	-	Set to true to hide large number warning.

Return value

A random number with the specified length.

.string(length, customChars)

Randomly generates a string with the specified length.

By default, all non-empty characters that are typable from a normal keyboard are included in the generation.

Default character set:

!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~

The default character set can be overriden by specifying your own character set in customChars parameter.

This method is not cryptographically secure.

Parameters

Parameter	Type	Default	Description
length	Number	-	Specify the expected length to be generated.
customChars	String	-	Specify the custom character set to override the default set.

Return value

A random string with the specified length.

.base62(length)

Randomly generates a string with the specified length with only base62 character sets.

Characters within the base62 range can be used safely on the web without further encoding. It can ideally be used to generate a non-security related random ID.

This method is not cryptographically secure.

Parameters

Parameter	Type	Default	Description
length	Number	-	Specify the expected length to be generated.

Return value

A set of random numbers encoded to base64 string.

.base64(bytes)

Randomly generates N bytes of base64 encoded string.

Internally, this method generates a random number from 0 to 255 to be base64 encoded.

This method is not cryptographically secure.

Parameters

Parameter	Type	Default	Description
bytes	Number	-	Specify the expected bytes to be generated.

Return value

A set of random numbers encoded to base64 string.

.hex(bytes, useUpperCase)

Randomly generates N bytes of hex encoded string. Each byte will contain 2 hex characters.

Internally, this method generates a random number from 0 to 255 to be hex encoded.

By default, the result will be generated using lowercase characters. To generate in uppercase characters, use the useUpperCase paramater.

This method is not cryptographically secure.

Parameters

Parameter	Type	Default	Description
bytes	Number	-	Specify the expected bytes to be generated.
useUpperCase	Boolean	-	Set to true to use uppercase characters.

Return value

A set of random numbers encoded to hexadecimal string.

.bytes(bytes, encoding)

Randomly generates N bytes of cryptographically secure buffer or string.

This method uses Node's Crypto module in Node or Web Crypto API in browsers.

Supported encoding:

Encoding	Node	Browser
hex	✔	✔
base64	✔	✔
ascii	✔	❌
utf8	✔	❌
utf16le	✔	❌
ucs2	✔	❌
latin1	✔	❌
binary	✔	❌

Parameters

Parameter	Type	Default	Description
bytes	Number	-	Specify the expected bytes to be generated.
encoding	String	-	Specify the encoding to be used.

Return value

If encoding is specified, returns a encoded string.

Otherwise, Buffer is returned in Node, or Uint8Array is returned in browser.