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Sarj Sarj Sarj Standards

prefer-node-crypto-hash

Prefer the modern one-shot node:crypto hash API when streaming state is unnecessary.

preferNodeCryptoHash Rule source Tests Catalog JSON

Why

A createHash-update-digest chain allocates mutable streaming state for a single in-memory value; Node's built-in hash function expresses the one-shot operation directly and can use its optimized fast path.

Fix

On a supported Node runtime, consider hash(algorithm, value, encoding). Preserve the output encoding explicitly: digest() returns a Buffer, while hash defaults to hex. Keep createHash for streams or multiple updates.

Examples

Before — flagged Avoid mutable state for one value
case.ts
import { createHash } from "node:crypto";
export const digest = createHash("sha256").update("value").digest("hex");
After — preferred Use Node's one-shot hash API
case.ts
import { hash } from "node:crypto";
export const digest = hash("sha256", "value", "hex");

References