@noble/hashes 1.4.0: toBytes

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify @noble/hashes.toBytes in pkg:npm/%40noble/hashes@1.4.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40noble/hashes@1.4.0
Demonstrate these symbols/APIs:
  - @noble/hashes.toBytes
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:c13a108ed25b05821e8eb3767eab2d1a6d1db0240355669ef82cc3e8357aea37","constraints":{"executionContext":"node"},"contract":["toBytes is exported as a function from @noble/hashes/utils","toBytes converts string input to UTF-8 encoded Uint8Array","toBytes passes Uint8Array input through without copying","toBytes converts empty string to empty Uint8Array","toBytes handles multibyte Unicode characters and emojis","toBytes throws an Error for invalid input types"],"goal":"verify @noble/hashes.toBytes in pkg:npm/%40noble/hashes@1.4.0","kind":"HOW","packages":["pkg:npm/%40noble/hashes@1.4.0"],"schemaVersion":1,"symbols":["@noble/hashes.toBytes"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40noble/hashes@1.4.0"],"schemaVersion":1,"subject":"pkg:npm/%40noble/hashes@1.4.0","symbols":["@noble/hashes.toBytes"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-noble-hashes-to-bytes",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-noble-hashes-to-bytes",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@noble/hashes": "1.4.0"
      }
    },
    "node_modules/@noble/hashes": {
      "version": "1.4.0",
      "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-1.4.0.tgz",
      "integrity": "sha512-V1JJ1WTRUqHHrOSh597hURcMqVKVGL/ea3kv0gSnEdsEZ0/+VyPghM1lMNGc00z7CIQorSvbKpuJkxvuHbvdbg==",
      "license": "MIT",
      "engines": {
        "node": ">= 16"
      },
      "funding": {
        "url": "https://paulmillr.com/funding/"
      }
    }
  }
}

{
  "name": "sample-noble-hashes-to-bytes",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room code sample for @noble/hashes toBytes",
  "main": "src/index.js",
  "license": "MIT-0",
  "dependencies": {
    "@noble/hashes": "1.4.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @noble/hashes.toBytes in pkg:npm/%40noble/hashes@1.4.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40noble/hashes@1.4.0"
  ],
  "symbols": [
    "@noble/hashes.toBytes"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

'use strict';

const { toBytes } = require('@noble/hashes/utils');

/**
 * Normalizes input (string or Uint8Array) into a Uint8Array.
 * If input is a string, it is UTF-8 encoded into a Uint8Array.
 * If input is already a Uint8Array, it is returned directly without copying.
 *
 * @param {string | Uint8Array} data - String or Uint8Array to normalize.
 * @returns {Uint8Array} Normalized byte array.
 */
function normalizeBytes(data) {
  return toBytes(data);
}

module.exports = {
  toBytes,
  normalizeBytes
};

import assert from 'node:assert/strict';
import { toBytes, normalizeBytes } from '../src/index.js';
import * as utils from '@noble/hashes/utils';

// 1. toBytes is exported as a function from @noble/hashes/utils
assert.equal(typeof utils.toBytes, 'function', 'toBytes must be exported from @noble/hashes/utils');
assert.equal(typeof toBytes, 'function', 'toBytes helper must be a function');
assert.equal(typeof normalizeBytes, 'function', 'normalizeBytes helper must be a function');

// 2. toBytes converts string input to UTF-8 encoded Uint8Array
const asciiStr = 'hello world';
const asciiBytes = toBytes(asciiStr);
assert(asciiBytes instanceof Uint8Array, 'result must be a Uint8Array');
assert.deepEqual(
  Array.from(asciiBytes),
  [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100],
  'ASCII string must match expected byte values'
);
assert.deepEqual(
  Array.from(normalizeBytes(asciiStr)),
  [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100],
  'normalizeBytes wrapper must match toBytes output'
);

// 3. toBytes passes Uint8Array input through without copying
const original = new Uint8Array([10, 20, 30, 40]);
const result = toBytes(original);
assert.equal(result, original, 'Uint8Array input must return same reference without copying');
assert.equal(normalizeBytes(original), original, 'normalizeBytes must preserve Uint8Array reference');

// 4. toBytes converts empty string to empty Uint8Array
const emptyRes = toBytes('');
assert(emptyRes instanceof Uint8Array, 'empty string must return Uint8Array');
assert.equal(emptyRes.length, 0, 'empty string must produce 0-length Uint8Array');

// 5. toBytes handles multibyte Unicode characters and emojis
const unicodeStr = 'noble ⚡ 한글 🔒';
const unicodeBytes = toBytes(unicodeStr);
const expectedUnicode = Array.from(new TextEncoder().encode(unicodeStr));
assert.deepEqual(
  Array.from(unicodeBytes),
  expectedUnicode,
  'multibyte unicode string must match TextEncoder bytes'
);

// 6. toBytes throws an Error for invalid input types
const invalidInputs = [
  123,
  null,
  undefined,
  true,
  false,
  {},
  [1, 2, 3]
];

for (const input of invalidInputs) {
  assert.throws(
    () => toBytes(input),
    {
      name: 'Error',
      message: 'Uint8Array expected'
    },
    `toBytes must throw 'Uint8Array expected' for invalid input: ${String(input)}`
  );
}

console.log('All @noble/hashes.toBytes contract tests passed.');