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nanoid - npm Package Compare versions

Comparing version
3.3.10
 to
3.3.11
+0
-35
async/index.browser.js
let random = async bytes => crypto.getRandomValues(new Uint8Array(bytes))
let customAlphabet = (alphabet, defaultSize = 21) => {
// First, a bitmask is necessary to generate the ID. The bitmask makes bytes
// values closer to the alphabet size. The bitmask calculates the closest
// `2^31 - 1` number, which exceeds the alphabet size.
// For example, the bitmask for the alphabet size 30 is 31 (00011111).
// `Math.clz32` is not used, because it is not available in browsers.
let mask = (2 << (Math.log(alphabet.length - 1) / Math.LN2)) - 1
// Though, the bitmask solution is not perfect since the bytes exceeding
// the alphabet size are refused. Therefore, to reliably generate the ID,
// the random bytes redundancy has to be satisfied.
// Note: every hardware random generator call is performance expensive,
// because the system call for entropy collection takes a lot of time.
// So, to avoid additional system calls, extra bytes are requested in advance.
// Next, a step determines how many random bytes to generate.
// The number of random bytes gets decided upon the ID size, mask,
// alphabet size, and magic number 1.6 (using 1.6 peaks at performance
// according to benchmarks).
// `-~f => Math.ceil(f)` if f is a float
// `-~i => i + 1` if i is an integer
let step = -~((1.6 * mask * defaultSize) / alphabet.length)
return async (size = defaultSize) => {

@@ -31,6 +9,4 @@ let id = ''

let bytes = crypto.getRandomValues(new Uint8Array(step))
// A compact alternative for `for (var i = 0; i < step; i++)`.
let i = step | 0
while (i--) {
// Adding `|| ''` refuses a random byte that exceeds the alphabet size.
id += alphabet[bytes[i] & mask] || ''

@@ -42,20 +18,10 @@ if (id.length === size) return id

}
let nanoid = async (size = 21) => {
let id = ''
let bytes = crypto.getRandomValues(new Uint8Array((size |= 0)))
// A compact alternative for `for (var i = 0; i < step; i++)`.
while (size--) {
// It is incorrect to use bytes exceeding the alphabet size.
// The following mask reduces the random byte in the 0-255 value
// range to the 0-63 value range. Therefore, adding hacks, such
// as empty string fallback or magic numbers, is unneccessary because
// the bitmask trims bytes down to the alphabet size.
let byte = bytes[size] & 63
if (byte < 36) {
// `0-9a-z`
id += byte.toString(36)
} else if (byte < 62) {
// `A-Z`
id += (byte - 26).toString(36).toUpperCase()

@@ -70,3 +36,2 @@ } else if (byte < 63) {

}
export { nanoid, customAlphabet, random }
+0
-36
async/index.js
import crypto from 'crypto'
import { urlAlphabet } from '../url-alphabet/index.js'
// `crypto.randomFill()` is a little faster than `crypto.randomBytes()`,
// because it is possible to use in combination with `Buffer.allocUnsafe()`.
let random = bytes =>
new Promise((resolve, reject) => {
// `Buffer.allocUnsafe()` is faster because it doesn’t flush the memory.
// Memory flushing is unnecessary since the buffer allocation itself resets
// the memory with the new bytes.
crypto.randomFill(Buffer.allocUnsafe(bytes), (err, buf) => {

@@ -20,29 +13,9 @@ if (err) {

})
let customAlphabet = (alphabet, defaultSize = 21) => {
// First, a bitmask is necessary to generate the ID. The bitmask makes bytes
// values closer to the alphabet size. The bitmask calculates the closest
// `2^31 - 1` number, which exceeds the alphabet size.
// For example, the bitmask for the alphabet size 30 is 31 (00011111).
let mask = (2 << (31 - Math.clz32((alphabet.length - 1) | 1))) - 1
// Though, the bitmask solution is not perfect since the bytes exceeding
// the alphabet size are refused. Therefore, to reliably generate the ID,
// the random bytes redundancy has to be satisfied.
// Note: every hardware random generator call is performance expensive,
// because the system call for entropy collection takes a lot of time.
// So, to avoid additional system calls, extra bytes are requested in advance.
// Next, a step determines how many random bytes to generate.
// The number of random bytes gets decided upon the ID size, mask,
// alphabet size, and magic number 1.6 (using 1.6 peaks at performance
// according to benchmarks).
let step = Math.ceil((1.6 * mask * defaultSize) / alphabet.length)
let tick = (id, size = defaultSize) =>
random(step).then(bytes => {
// A compact alternative for `for (var i = 0; i < step; i++)`.
let i = step
while (i--) {
// Adding `|| ''` refuses a random byte that exceeds the alphabet size.
id += alphabet[bytes[i] & mask] || ''

@@ -53,16 +26,8 @@ if (id.length >= size) return id

})
return size => tick('', size)
}
let nanoid = (size = 21) =>
random((size |= 0)).then(bytes => {
let id = ''
// A compact alternative for `for (var i = 0; i < step; i++)`.
while (size--) {
// It is incorrect to use bytes exceeding the alphabet size.
// The following mask reduces the random byte in the 0-255 value
// range to the 0-63 value range. Therefore, adding hacks, such
// as empty string fallback or magic numbers, is unneccessary because
// the bitmask trims bytes down to the alphabet size.
id += urlAlphabet[bytes[size] & 63]

@@ -72,3 +37,2 @@ }

})
export { nanoid, customAlphabet, random }
+0
-31
async/index.native.js
import { getRandomBytesAsync } from 'expo-random'
import { urlAlphabet } from '../url-alphabet/index.js'
let random = getRandomBytesAsync
let customAlphabet = (alphabet, defaultSize = 21) => {
// First, a bitmask is necessary to generate the ID. The bitmask makes bytes
// values closer to the alphabet size. The bitmask calculates the closest
// `2^31 - 1` number, which exceeds the alphabet size.
// For example, the bitmask for the alphabet size 30 is 31 (00011111).
let mask = (2 << (31 - Math.clz32((alphabet.length - 1) | 1))) - 1
// Though, the bitmask solution is not perfect since the bytes exceeding
// the alphabet size are refused. Therefore, to reliably generate the ID,
// the random bytes redundancy has to be satisfied.
// Note: every hardware random generator call is performance expensive,
// because the system call for entropy collection takes a lot of time.
// So, to avoid additional system calls, extra bytes are requested in advance.
// Next, a step determines how many random bytes to generate.
// The number of random bytes gets decided upon the ID size, mask,
// alphabet size, and magic number 1.6 (using 1.6 peaks at performance
// according to benchmarks).
let step = Math.ceil((1.6 * mask * defaultSize) / alphabet.length)
let tick = (id, size = defaultSize) =>
random(step).then(bytes => {
// A compact alternative for `for (var i = 0; i < step; i++)`.
let i = step
while (i--) {
// Adding `|| ''` refuses a random byte that exceeds the alphabet size.
id += alphabet[bytes[i] & mask] || ''

@@ -38,16 +16,8 @@ if (id.length >= size) return id

})
return size => tick('', size)
}
let nanoid = (size = 21) =>
random((size |= 0)).then(bytes => {
let id = ''
// A compact alternative for `for (var i = 0; i < step; i++)`.
while (size--) {
// It is incorrect to use bytes exceeding the alphabet size.
// The following mask reduces the random byte in the 0-255 value
// range to the 0-63 value range. Therefore, adding hacks, such
// as empty string fallback or magic numbers, is unneccessary because
// the bitmask trims bytes down to the alphabet size.
id += urlAlphabet[bytes[size] & 63]

@@ -57,3 +27,2 @@ }

})
export { nanoid, customAlphabet, random }
+0
-38
index.browser.js

@@ -1,32 +0,6 @@

// This file replaces `index.js` in bundlers like webpack or Rollup,
// according to `browser` config in `package.json`.
import { urlAlphabet } from './url-alphabet/index.js'
let random = bytes => crypto.getRandomValues(new Uint8Array(bytes))
let customRandom = (alphabet, defaultSize, getRandom) => {
// First, a bitmask is necessary to generate the ID. The bitmask makes bytes
// values closer to the alphabet size. The bitmask calculates the closest
// `2^31 - 1` number, which exceeds the alphabet size.
// For example, the bitmask for the alphabet size 30 is 31 (00011111).
// `Math.clz32` is not used, because it is not available in browsers.
let mask = (2 << (Math.log(alphabet.length - 1) / Math.LN2)) - 1
// Though, the bitmask solution is not perfect since the bytes exceeding
// the alphabet size are refused. Therefore, to reliably generate the ID,
// the random bytes redundancy has to be satisfied.
// Note: every hardware random generator call is performance expensive,
// because the system call for entropy collection takes a lot of time.
// So, to avoid additional system calls, extra bytes are requested in advance.
// Next, a step determines how many random bytes to generate.
// The number of random bytes gets decided upon the ID size, mask,
// alphabet size, and magic number 1.6 (using 1.6 peaks at performance
// according to benchmarks).
// `-~f => Math.ceil(f)` if f is a float
// `-~i => i + 1` if i is an integer
let step = -~((1.6 * mask * defaultSize) / alphabet.length)
return (size = defaultSize) => {

@@ -36,6 +10,4 @@ let id = ''

let bytes = getRandom(step)
// A compact alternative for `for (var i = 0; i < step; i++)`.
let j = step | 0
while (j--) {
// Adding `|| ''` refuses a random byte that exceeds the alphabet size.
id += alphabet[bytes[j] & mask] || ''

@@ -47,19 +19,10 @@ if (id.length === size) return id

}
let customAlphabet = (alphabet, size = 21) =>
customRandom(alphabet, size, random)
let nanoid = (size = 21) =>
crypto.getRandomValues(new Uint8Array(size)).reduce((id, byte) => {
// It is incorrect to use bytes exceeding the alphabet size.
// The following mask reduces the random byte in the 0-255 value
// range to the 0-63 value range. Therefore, adding hacks, such
// as empty string fallback or magic numbers, is unneccessary because
// the bitmask trims bytes down to the alphabet size.
byte &= 63
if (byte < 36) {
// `0-9a-z`
id += byte.toString(36)
} else if (byte < 62) {
// `A-Z`
id += (byte - 26).toString(36).toUpperCase()

@@ -73,3 +36,2 @@ } else if (byte > 62) {

}, '')
export { nanoid, customAlphabet, customRandom, urlAlphabet, random }
+0
-40
index.js
import crypto from 'crypto'
import { urlAlphabet } from './url-alphabet/index.js'
// It is best to make fewer, larger requests to the crypto module to
// avoid system call overhead. So, random numbers are generated in a
// pool. The pool is a Buffer that is larger than the initial random
// request size by this multiplier. The pool is enlarged if subsequent
// requests exceed the maximum buffer size.
const POOL_SIZE_MULTIPLIER = 128
let pool, poolOffset
let fillPool = bytes => {

@@ -24,29 +16,9 @@ if (!pool || pool.length < bytes) {

}
let random = bytes => {
// `|=` convert `bytes` to number to prevent `valueOf` abusing and pool pollution
fillPool((bytes |= 0))
return pool.subarray(poolOffset - bytes, poolOffset)
}
let customRandom = (alphabet, defaultSize, getRandom) => {
// First, a bitmask is necessary to generate the ID. The bitmask makes bytes
// values closer to the alphabet size. The bitmask calculates the closest
// `2^31 - 1` number, which exceeds the alphabet size.
// For example, the bitmask for the alphabet size 30 is 31 (00011111).
let mask = (2 << (31 - Math.clz32((alphabet.length - 1) | 1))) - 1
// Though, the bitmask solution is not perfect since the bytes exceeding
// the alphabet size are refused. Therefore, to reliably generate the ID,
// the random bytes redundancy has to be satisfied.
// Note: every hardware random generator call is performance expensive,
// because the system call for entropy collection takes a lot of time.
// So, to avoid additional system calls, extra bytes are requested in advance.
// Next, a step determines how many random bytes to generate.
// The number of random bytes gets decided upon the ID size, mask,
// alphabet size, and magic number 1.6 (using 1.6 peaks at performance
// according to benchmarks).
let step = Math.ceil((1.6 * mask * defaultSize) / alphabet.length)
return (size = defaultSize) => {

@@ -56,6 +28,4 @@ let id = ''

let bytes = getRandom(step)
// A compact alternative for `for (let i = 0; i < step; i++)`.
let i = step
while (i--) {
// Adding `|| ''` refuses a random byte that exceeds the alphabet size.
id += alphabet[bytes[i] & mask] || ''

@@ -67,17 +37,8 @@ if (id.length === size) return id

}
let customAlphabet = (alphabet, size = 21) =>
customRandom(alphabet, size, random)
let nanoid = (size = 21) => {
// `|=` convert `size` to number to prevent `valueOf` abusing and pool pollution
fillPool((size |= 0))
let id = ''
// We are reading directly from the random pool to avoid creating new array
for (let i = poolOffset - size; i < poolOffset; i++) {
// It is incorrect to use bytes exceeding the alphabet size.
// The following mask reduces the random byte in the 0-255 value
// range to the 0-63 value range. Therefore, adding hacks, such
// as empty string fallback or magic numbers, is unneccessary because
// the bitmask trims bytes down to the alphabet size.
id += urlAlphabet[pool[i] & 63]

@@ -87,3 +48,2 @@ }

}
export { nanoid, customAlphabet, customRandom, urlAlphabet, random }
+0
-13
non-secure/index.js

@@ -1,17 +0,8 @@

// This alphabet uses `A-Za-z0-9_-` symbols.
// The order of characters is optimized for better gzip and brotli compression.
// References to the same file (works both for gzip and brotli):
// `'use`, `andom`, and `rict'`
// References to the brotli default dictionary:
// `-26T`, `1983`, `40px`, `75px`, `bush`, `jack`, `mind`, `very`, and `wolf`
let urlAlphabet =
'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict'
let customAlphabet = (alphabet, defaultSize = 21) => {
return (size = defaultSize) => {
let id = ''
// A compact alternative for `for (var i = 0; i < step; i++)`.
let i = size | 0
while (i--) {
// `| 0` is more compact and faster than `Math.floor()`.
id += alphabet[(Math.random() * alphabet.length) | 0]

@@ -22,9 +13,6 @@ }

}
let nanoid = (size = 21) => {
let id = ''
// A compact alternative for `for (var i = 0; i < step; i++)`.
let i = size | 0
while (i--) {
// `| 0` is more compact and faster than `Math.floor()`.
id += urlAlphabet[(Math.random() * 64) | 0]

@@ -34,3 +22,2 @@ }

}
export { nanoid, customAlphabet }
+3
-2
package.json
{
"name": "nanoid",
"version": "3.3.10",
"version": "3.3.11",
"description": "A tiny (116 bytes), secure URL-friendly unique string ID generator",

@@ -38,2 +38,3 @@ "keywords": [

".": {
"react-native": "./index.browser.js",
"browser": "./index.browser.js",

@@ -89,2 +90,2 @@ "require": {

}
}
}
+2
-517
README.md

@@ -38,518 +38,3 @@ # Nano ID

## Table of Contents
* [Comparison with UUID](#comparison-with-uuid)
* [Benchmark](#benchmark)
* [Security](#security)
* [API](#api)
* [Blocking](#blocking)
* [Async](#async)
* [Non-Secure](#non-secure)
* [Custom Alphabet or Size](#custom-alphabet-or-size)
* [Custom Random Bytes Generator](#custom-random-bytes-generator)
* [Usage](#usage)
* [IE](#ie)
* [React](#react)
* [React Native](#react-native)
* [Rollup](#rollup)
* [PouchDB and CouchDB](#pouchdb-and-couchdb)
* [Mongoose](#mongoose)
* [Web Workers](#web-workers)
* [CLI](#cli)
* [Other Programming Languages](#other-programming-languages)
* [Tools](#tools)
## Comparison with UUID
Nano ID is quite comparable to UUID v4 (random-based).
It has a similar number of random bits in the ID
(126 in Nano ID and 122 in UUID), so it has a similar collision probability:
> For there to be a one in a billion chance of duplication,
> 103 trillion version 4 IDs must be generated.
There are three main differences between Nano ID and UUID v4:
1. Nano ID uses a bigger alphabet, so a similar number of random bits
are packed in just 21 symbols instead of 36.
2. Nano ID code is **4 times less** than `uuid/v4` package:
130 bytes instead of 483.
3. Because of memory allocation tricks, Nano ID is **2 times** faster than UUID.
## Benchmark
```rust
$ node ./test/benchmark.js
crypto.randomUUID 25,603,857 ops/sec
@napi-rs/uuid 9,973,819 ops/sec
uid/secure 8,234,798 ops/sec
@lukeed/uuid 7,464,706 ops/sec
nanoid 5,616,592 ops/sec
customAlphabet 3,115,207 ops/sec
uuid v4 1,535,753 ops/sec
secure-random-string 388,226 ops/sec
uid-safe.sync 363,489 ops/sec
cuid 187,343 ops/sec
shortid 45,758 ops/sec
Async:
nanoid/async 96,094 ops/sec
async customAlphabet 97,184 ops/sec
async secure-random-string 92,794 ops/sec
uid-safe 90,684 ops/sec
Non-secure:
uid 67,376,692 ops/sec
nanoid/non-secure 2,849,639 ops/sec
rndm 2,674,806 ops/sec
```
Test configuration: ThinkPad X1 Carbon Gen 9, Fedora 34, Node.js 16.10.
## Security
*See a good article about random generators theory:
[Secure random values (in Node.js)]*
* **Unpredictability.** Instead of using the unsafe `Math.random()`, Nano ID
uses the `crypto` module in Node.js and the Web Crypto API in browsers.
These modules use unpredictable hardware random generator.
* **Uniformity.** `random % alphabet` is a popular mistake to make when coding
an ID generator. The distribution will not be even; there will be a lower
chance for some symbols to appear compared to others. So, it will reduce
the number of tries when brute-forcing. Nano ID uses a [better algorithm]
and is tested for uniformity.
<img src="img/distribution.png" alt="Nano ID uniformity"
width="340" height="135">
* **Well-documented:** all Nano ID hacks are documented. See comments
in [the source].
* **Vulnerabilities:** to report a security vulnerability, please use
the [Tidelift security contact](https://tidelift.com/security).
Tidelift will coordinate the fix and disclosure.
[Secure random values (in Node.js)]: https://gist.github.com/joepie91/7105003c3b26e65efcea63f3db82dfba
[better algorithm]: https://github.com/ai/nanoid/blob/main/index.js
[the source]: https://github.com/ai/nanoid/blob/main/index.js
## Install
```bash
npm install --save nanoid
```
For quick hacks, you can load Nano ID from CDN. Though, it is not recommended
to be used in production because of the lower loading performance.
```js
import { nanoid } from 'https://cdn.jsdelivr.net/npm/nanoid/nanoid.js'
```
Nano ID provides ES modules. You do not need to do anything to use Nano ID
as ESM in webpack, Rollup, Parcel, or Node.js.
```js
import { nanoid } from 'nanoid'
```
In Node.js you can use CommonJS import:
```js
const { nanoid } = require('nanoid')
```
## API
Nano ID has 3 APIs: normal (blocking), asynchronous, and non-secure.
By default, Nano ID uses URL-friendly symbols (`A-Za-z0-9_-`) and returns an ID
with 21 characters (to have a collision probability similar to UUID v4).
### Blocking
The safe and easiest way to use Nano ID.
In rare cases could block CPU from other work while noise collection
for hardware random generator.
```js
import { nanoid } from 'nanoid'
model.id = nanoid() //=> "V1StGXR8_Z5jdHi6B-myT"
```
If you want to reduce the ID size (and increase collisions probability),
you can pass the size as an argument.
```js
nanoid(10) //=> "IRFa-VaY2b"
```
Don’t forget to check the safety of your ID size
in our [ID collision probability] calculator.
You can also use a [custom alphabet](#custom-alphabet-or-size)
or a [random generator](#custom-random-bytes-generator).
[ID collision probability]: https://zelark.github.io/nano-id-cc/
### Async
To generate hardware random bytes, CPU collects electromagnetic noise.
For most cases, entropy will be already collected.
In the synchronous API during the noise collection, the CPU is busy and
cannot do anything useful (for instance, process another HTTP request).
Using the asynchronous API of Nano ID, another code can run during
the entropy collection.
```js
import { nanoid } from 'nanoid/async'
async function createUser () {
user.id = await nanoid()
}
```
Read more about entropy collection in [`crypto.randomBytes`] docs.
Unfortunately, you will lose Web Crypto API advantages in a browser
if you use the asynchronous API. So, currently, in the browser, you are limited
with either security (`nanoid`), asynchronous behavior (`nanoid/async`),
or non-secure behavior (`nanoid/non-secure`) that will be explained
in the next part of the documentation.
[`crypto.randomBytes`]: https://nodejs.org/api/crypto.html#crypto_crypto_randombytes_size_callback
### Non-Secure
By default, Nano ID uses hardware random bytes generation for security
and low collision probability. If you are not so concerned with security,
you can use the faster non-secure generator.
```js
import { nanoid } from 'nanoid/non-secure'
const id = nanoid() //=> "Uakgb_J5m9g-0JDMbcJqLJ"
```
### Custom Alphabet or Size
`customAlphabet` allows you to create `nanoid` with your own alphabet
and ID size.
```js
import { customAlphabet } from 'nanoid'
const nanoid = customAlphabet('1234567890abcdef', 10)
model.id = nanoid() //=> "4f90d13a42"
```
```js
import { customAlphabet } from 'nanoid/async'
const nanoid = customAlphabet('1234567890abcdef', 10)
async function createUser () {
user.id = await nanoid()
}
```
```js
import { customAlphabet } from 'nanoid/non-secure'
const nanoid = customAlphabet('1234567890abcdef', 10)
user.id = nanoid()
```
Check the safety of your custom alphabet and ID size in our
[ID collision probability] calculator. For more alphabets, check out the options
in [`nanoid-dictionary`].
Alphabet must contain 256 symbols or less.
Otherwise, the security of the internal generator algorithm is not guaranteed.
In addition to setting a default size, you can change the ID size when calling
the function:
```js
import { customAlphabet } from 'nanoid'
const nanoid = customAlphabet('1234567890abcdef', 10)
model.id = nanoid(5) //=> "f01a2"
```
[ID collision probability]: https://alex7kom.github.io/nano-nanoid-cc/
[`nanoid-dictionary`]: https://github.com/CyberAP/nanoid-dictionary
### Custom Random Bytes Generator
`customRandom` allows you to create a `nanoid` and replace alphabet
and the default random bytes generator.
In this example, a seed-based generator is used:
```js
import { customRandom } from 'nanoid'
const rng = seedrandom(seed)
const nanoid = customRandom('abcdef', 10, size => {
return (new Uint8Array(size)).map(() => 256 * rng())
})
nanoid() //=> "fbaefaadeb"
```
`random` callback must accept the array size and return an array
with random numbers.
If you want to use the same URL-friendly symbols with `customRandom`,
you can get the default alphabet using the `urlAlphabet`.
```js
const { customRandom, urlAlphabet } = require('nanoid')
const nanoid = customRandom(urlAlphabet, 10, random)
```
Asynchronous and non-secure APIs are not available for `customRandom`.
Note, that between Nano ID versions we may change random generator
call sequence. If you are using seed-based generators, we do not guarantee
the same result.
## Usage
### IE
If you support IE, you need to [transpile `node_modules`] by Babel
and add `crypto` alias. Moreover, `UInt8Array` in IE actually
is not an array and to cope with it, you have to convert it to an array
manually:
```js
// polyfills.js
if (!window.crypto && window.msCrypto) {
window.crypto = window.msCrypto
const getRandomValuesDef = window.crypto.getRandomValues
window.crypto.getRandomValues = function (array) {
const values = getRandomValuesDef.call(window.crypto, array)
const result = []
for (let i = 0; i < array.length; i++) {
result[i] = values[i];
}
return result
};
}
```
```js
import './polyfills.js'
import { nanoid } from 'nanoid'
```
[transpile `node_modules`]: https://developer.epages.com/blog/coding/how-to-transpile-node-modules-with-babel-and-webpack-in-a-monorepo/
### React
There’s no correct way to use Nano ID for React `key` prop
since it should be consistent among renders.
```jsx
function Todos({todos}) {
return (
<ul>
{todos.map(todo => (
<li key={nanoid()}> /* DON’T DO IT */
{todo.text}
</li>
))}
</ul>
)
}
```
You should rather try to reach for stable ID inside your list item.
```jsx
const todoItems = todos.map((todo) =>
<li key={todo.id}>
{todo.text}
</li>
)
```
In case you don’t have stable IDs you'd rather use index as `key`
instead of `nanoid()`:
```jsx
const todoItems = todos.map((text, index) =>
<li key={index}> /* Still not recommended but preferred over nanoid().
Only do this if items have no stable IDs. */
{text}
</li>
)
```
### React Native
React Native does not have built-in random generator. The following polyfill
works for plain React Native and Expo starting with `39.x`.
1. Check [`react-native-get-random-values`] docs and install it.
2. Import it before Nano ID.
```js
import 'react-native-get-random-values'
import { nanoid } from 'nanoid'
```
[`react-native-get-random-values`]: https://github.com/LinusU/react-native-get-random-values
### Rollup
For Rollup you will need [`@rollup/plugin-node-resolve`] to bundle browser version
of this library.:
```js
plugins: [
nodeResolve({
browser: true
})
]
```
[`@rollup/plugin-node-resolve`]: https://github.com/rollup/plugins/tree/master/packages/node-resolve
### PouchDB and CouchDB
In PouchDB and CouchDB, IDs can’t start with an underscore `_`.
A prefix is required to prevent this issue, as Nano ID might use a `_`
at the start of the ID by default.
Override the default ID with the following option:
```js
db.put({
_id: 'id' + nanoid(),
…
})
```
### Mongoose
```js
const mySchema = new Schema({
_id: {
type: String,
default: () => nanoid()
}
})
```
### Web Workers
Web Workers do not have access to a secure random generator.
Security is important in IDs when IDs should be unpredictable.
For instance, in "access by URL" link generation.
If you do not need unpredictable IDs, but you need to use Web Workers,
you can use the non‑secure ID generator.
```js
import { nanoid } from 'nanoid/non-secure'
nanoid() //=> "Uakgb_J5m9g-0JDMbcJqLJ"
```
Note: non-secure IDs are more prone to collision attacks.
### CLI
You can get unique ID in terminal by calling `npx nanoid`. You need only
Node.js in the system. You do not need Nano ID to be installed anywhere.
```sh
$ npx nanoid
npx: installed 1 in 0.63s
LZfXLFzPPR4NNrgjlWDxn
```
Size of generated ID can be specified with `--size` (or `-s`) option:
```sh
$ npx nanoid --size 10
L3til0JS4z
```
Custom alphabet can be specified with `--alphabet` (or `-a`) option
(note that in this case `--size` is required):
```sh
$ npx nanoid --alphabet abc --size 15
bccbcabaabaccab
```
### Other Programming Languages
Nano ID was ported to many languages. You can use these ports to have
the same ID generator on the client and server side.
* [C#](https://github.com/codeyu/nanoid-net)
* [C++](https://github.com/mcmikecreations/nanoid_cpp)
* [Clojure and ClojureScript](https://github.com/zelark/nano-id)
* [ColdFusion/CFML](https://github.com/JamoCA/cfml-nanoid)
* [Crystal](https://github.com/mamantoha/nanoid.cr)
* [Dart & Flutter](https://github.com/pd4d10/nanoid-dart)
* [Deno](https://github.com/ianfabs/nanoid)
* [Go](https://github.com/matoous/go-nanoid)
* [Elixir](https://github.com/railsmechanic/nanoid)
* [Haskell](https://github.com/MichelBoucey/NanoID)
* [Janet](https://sr.ht/~statianzo/janet-nanoid/)
* [Java](https://github.com/aventrix/jnanoid)
* [Nim](https://github.com/icyphox/nanoid.nim)
* [OCaml](https://github.com/routineco/ocaml-nanoid)
* [Perl](https://github.com/tkzwtks/Nanoid-perl)
* [PHP](https://github.com/hidehalo/nanoid-php)
* [Python](https://github.com/puyuan/py-nanoid)
with [dictionaries](https://pypi.org/project/nanoid-dictionary)
* [Postgres Extension](https://github.com/spa5k/uids-postgres)
* [R](https://github.com/hrbrmstr/nanoid) (with dictionaries)
* [Ruby](https://github.com/radeno/nanoid.rb)
* [Rust](https://github.com/nikolay-govorov/nanoid)
* [Swift](https://github.com/antiflasher/NanoID)
* [Unison](https://share.unison-lang.org/latest/namespaces/hojberg/nanoid)
* [V](https://github.com/invipal/nanoid)
* [Zig](https://github.com/SasLuca/zig-nanoid)
For other environments, [CLI] is available to generate IDs from a command line.
[CLI]: #cli
## Tools
* [ID size calculator] shows collision probability when adjusting
the ID alphabet or size.
* [`nanoid-dictionary`] with popular alphabets to use with [`customAlphabet`].
* [`nanoid-good`] to be sure that your ID doesn’t contain any obscene words.
[`nanoid-dictionary`]: https://github.com/CyberAP/nanoid-dictionary
[ID size calculator]: https://zelark.github.io/nano-id-cc/
[`customAlphabet`]: #custom-alphabet-or-size
[`nanoid-good`]: https://github.com/y-gagar1n/nanoid-good
## Docs
Read full docs **[here](https://github.com/ai/nanoid#readme)**.
+0
-4
url-alphabet/index.js

@@ -1,7 +0,3 @@

// This alphabet uses `A-Za-z0-9_-` symbols.
// The order of characters is optimized for better gzip and brotli compression.
// Same as in non-secure/index.js
let urlAlphabet =
'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict'
export { urlAlphabet }