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Random Number Generator in TypeScript
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export default class RandomGenerator { | |
public static generateRandomBytes(length: number): Uint8Array { | |
return crypto.getRandomValues(new Uint8Array(length)); | |
} | |
public static generateRandomNumber(min: number, max: number): number { | |
const range = max - min; | |
const maxGeneratedValue = 0xFFFFFFFF; | |
const possibleResultValues = range + 1; | |
const possibleGeneratedValues = maxGeneratedValue + 1; | |
const remainder = possibleGeneratedValues % possibleResultValues; | |
const maxUnbiased = maxGeneratedValue - remainder; | |
if (!Number.isInteger(min) || !Number.isInteger(max) || | |
max > Number.MAX_SAFE_INTEGER || min < Number.MIN_SAFE_INTEGER) { | |
throw new Error('Arguments must be safe integers.'); | |
} else if (range > maxGeneratedValue) { | |
throw new Error(`Range of ${range} (from ${min} to ${max}) > ${maxGeneratedValue}.`); | |
} else if (max < min) { | |
throw new Error(`max (${max}) must be >= min (${min}).`); | |
} else if (min === max) { | |
return min; | |
} | |
let generated; | |
do { | |
generated = crypto.getRandomValues(new Uint32Array(1))[0]; | |
} while (generated > maxUnbiased); | |
return min + (generated % possibleResultValues); | |
} | |
} |
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