pvutils 1.2.0: bufferToHexCodes

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 pvutils.bufferToHexCodes in pkg:npm/pvutils@1.2.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/pvutils@1.2.0
Demonstrate these symbols/APIs:
  - pvutils.bufferToHexCodes

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:sha256:622920d017be930b09c509b83a78f548668dd1bc7b197d2af4027478d42ed4ca","contract":["bufferToHexCodes converts an ArrayBuffer to an uppercase hexadecimal string without delimiters by default","bufferToHexCodes pads single-digit hexadecimal values with a leading zero","bufferToHexCodes formats an ArrayBuffer slice when given offset and length parameters","bufferToHexCodes separates each two-character hexadecimal byte with spaces when insertSpace is true","bufferToHexCodes returns an empty string when converting an empty ArrayBuffer"],"goal":"verify pvutils.bufferToHexCodes in pkg:npm/pvutils@1.2.0","kind":"HOW","packages":["pkg:npm/pvutils@1.2.0"],"schemaVersion":1,"symbols":["pvutils.bufferToHexCodes"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/pvutils@1.2.0"],"schemaVersion":1,"subject":"pkg:npm/pvutils@1.2.0","symbols":["pvutils.bufferToHexCodes"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-pvutils-buffertohexcodes",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pvutils-buffertohexcodes",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "pvutils": "1.2.0"
      }
    },
    "node_modules/pvutils": {
      "version": "1.2.0",
      "resolved": "https://registry.npmjs.org/pvutils/-/pvutils-1.2.0.tgz",
      "integrity": "sha512-BbubeCEyTuQjVMakvJQ/Sxbc93F2pwmbsxONT/ZRrwU7Ua38d8unYTwXpTVLAKJ4BDuH9IGztCjQcd/N/39Dvg==",
      "license": "MIT",
      "engines": {
        "node": ">=16.0.0"
      }
    }
  }
}

{
  "name": "sample-pvutils-buffertohexcodes",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification sample for pvutils.bufferToHexCodes",
  "type": "module",
  "main": "src/index.js",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "pvutils": "1.2.0"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify pvutils.bufferToHexCodes in pkg:npm/pvutils@1.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pvutils@1.2.0"
  ],
  "symbols": [
    "pvutils.bufferToHexCodes"
  ]
}

import { bufferToHexCodes } from 'pvutils';

/**
 * Converts an ArrayBuffer to a hexadecimal string.
 * @param {ArrayBuffer} buffer - Buffer to convert.
 * @param {number} [offset=0] - Starting offset.
 * @param {number} [length] - Number of bytes to convert.
 * @param {boolean} [insertSpace=false] - Whether to insert space between hex bytes.
 * @returns {string} Hexadecimal representation.
 */
export function toHexCodes(buffer, offset = 0, length = buffer.byteLength - offset, insertSpace = false) {
  return bufferToHexCodes(buffer, offset, length, insertSpace);
}

export { bufferToHexCodes };

import assert from 'node:assert';
import { bufferToHexCodes, toHexCodes } from '../src/index.js';

// 1. bufferToHexCodes converts an ArrayBuffer to an uppercase hexadecimal string without delimiters by default
const bytes = new Uint8Array([0x48, 0x65, 0x6C, 0x6C, 0x6F]); // "Hello"
const hex = bufferToHexCodes(bytes.buffer);
assert.strictEqual(typeof hex, 'string');
assert.strictEqual(hex, '48656C6C6F');
assert.strictEqual(toHexCodes(bytes.buffer), '48656C6C6F');

// 2. bufferToHexCodes pads single-digit hexadecimal values with a leading zero
const singleDigitBytes = new Uint8Array([0x00, 0x07, 0x0A, 0x0F, 0x10, 0xFF]);
const paddedHex = bufferToHexCodes(singleDigitBytes.buffer);
assert.strictEqual(paddedHex, '00070A0F10FF');

// 3. bufferToHexCodes formats an ArrayBuffer slice when given offset and length parameters
const sliceBuf = new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF, 0x01, 0x02]).buffer;
const subHex = bufferToHexCodes(sliceBuf, 1, 3);
assert.strictEqual(subHex, 'ADBEEF');

// 4. bufferToHexCodes separates each two-character hexadecimal byte with spaces when insertSpace is true
const spacedHex = bufferToHexCodes(sliceBuf, 1, 3, true);
assert.strictEqual(spacedHex, 'AD BE EF');

const fullSpaced = bufferToHexCodes(bytes.buffer, 0, bytes.buffer.byteLength, true);
assert.strictEqual(fullSpaced, '48 65 6C 6C 6F');

// 5. bufferToHexCodes returns an empty string when converting an empty ArrayBuffer
const emptyBuffer = new ArrayBuffer(0);
const emptyHex = bufferToHexCodes(emptyBuffer);
assert.strictEqual(emptyHex, '');
assert.strictEqual(toHexCodes(emptyBuffer), '');

console.log('Contract assertions passed.');