| 1 | const crypto = require('crypto') |
| 2 | |
| 3 | /** |
| 4 | * Generate a cryptographically secure random number in the [0,1[ range |
| 5 | * |
| 6 | * @returns |
| 7 | */ |
| 8 | function secureRandom () { |
| 9 | return crypto.randomBytes(4).readUInt32LE() / 0x100000000 |
| 10 | } |
| 11 | |
| 12 | /** |
| 13 | * @param max |
| 14 | * @param min |
| 15 | * @returns |
| 16 | */ |
| 17 | function generateRandomInteger (max = Number.MAX_SAFE_INTEGER, min = 0) { |
| 18 | if (max < 0) { |
| 19 | throw new RangeError('Invalid interval') |
| 20 | } |
| 21 | max = Math.floor(max) |
| 22 | if (min) { |
| 23 | if (max < min || min < 0) { |
| 24 | throw new RangeError('Invalid interval') |
| 25 | } |
| 26 | min = Math.ceil(min) |
| 27 | return Math.floor(secureRandom() * (max - min + 1)) + min |
| 28 | } |
| 29 | return Math.floor(secureRandom() * (max + 1)) |
| 30 | } |
| 31 | |
| 32 | /** |
| 33 | * |
| 34 | * @param size |
| 35 | * @param max |
| 36 | */ |
| 37 | function generateRandomIntegerArray (size, max = Number.MAX_SAFE_INTEGER) { |
| 38 | const integerArray = [] |
| 39 | for (let i = 0; i < size; i++) { |
| 40 | integerArray.push(generateRandomInteger(max)) |
| 41 | } |
| 42 | return integerArray |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * @param ms |
| 47 | * @returns |
| 48 | */ |
| 49 | async function sleep (ms) { |
| 50 | return new Promise(resolve => setTimeout(resolve, ms)) |
| 51 | } |
| 52 | |
| 53 | const LIST_FORMATTER = new Intl.ListFormat('en-US', { |
| 54 | style: 'long', |
| 55 | type: 'conjunction' |
| 56 | }) |
| 57 | |
| 58 | module.exports = { |
| 59 | generateRandomInteger, |
| 60 | generateRandomIntegerArray, |
| 61 | sleep, |
| 62 | secureRandom, |
| 63 | LIST_FORMATTER |
| 64 | } |