64 lines
1.9 KiB
JavaScript
64 lines
1.9 KiB
JavaScript
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import { urlAlphabet } from './url-alphabet/index.js'
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if (false) {
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if (
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typeof navigator !== 'undefined' &&
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navigator.product === 'ReactNative' &&
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typeof crypto === 'undefined'
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) {
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throw new Error(
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'React Native does not have a built-in secure random generator. ' +
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'If you don’t need unpredictable IDs use `nanoid/non-secure`. ' +
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'For secure IDs, import `react-native-get-random-values` ' +
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'before Nano ID.'
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)
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}
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if (typeof msCrypto !== 'undefined' && typeof crypto === 'undefined') {
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throw new Error(
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'Import file with `if (!window.crypto) window.crypto = window.msCrypto`' +
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' before importing Nano ID to fix IE 11 support'
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)
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}
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if (typeof crypto === 'undefined') {
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throw new Error(
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'Your browser does not have secure random generator. ' +
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'If you don’t need unpredictable IDs, you can use nanoid/non-secure.'
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)
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}
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}
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let random = bytes => crypto.getRandomValues(new Uint8Array(bytes))
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let customRandom = (alphabet, defaultSize, getRandom) => {
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let mask = (2 << (Math.log(alphabet.length - 1) / Math.LN2)) - 1
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let step = -~((1.6 * mask * defaultSize) / alphabet.length)
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return (size = defaultSize) => {
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let id = ''
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while (true) {
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let bytes = getRandom(step)
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let j = step
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while (j--) {
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id += alphabet[bytes[j] & mask] || ''
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if (id.length === size) return id
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}
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}
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}
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}
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let customAlphabet = (alphabet, size = 21) =>
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customRandom(alphabet, size, random)
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let nanoid = (size = 21) => {
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let id = ''
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let bytes = crypto.getRandomValues(new Uint8Array(size))
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while (size--) {
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let byte = bytes[size] & 63
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if (byte < 36) {
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id += byte.toString(36)
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} else if (byte < 62) {
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id += (byte - 26).toString(36).toUpperCase()
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} else if (byte < 63) {
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id += '_'
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} else {
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id += '-'
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}
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}
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return id
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}
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export { nanoid, customAlphabet, customRandom, urlAlphabet, random }
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