pvutils 1.2.0: toBase64

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.toBase64 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.toBase64

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:fc37f5a5e77bb130b787b32c68028a43e10522fce691541042c502924d23ccc2","contract":["toBase64 encodes ASCII strings to standard RFC 4648 Base64 format with proper padding","toBase64 uses URL-safe alphabet characters '-' and '_' when useUrlTemplate is true","toBase64 omits padding characters when skipPadding is true","toBase64 strips leading null characters when skipLeadingZeros is true","toBase64 returns an empty string when given an empty string input"],"goal":"verify pvutils.toBase64 in pkg:npm/pvutils@1.2.0","kind":"HOW","packages":["pkg:npm/pvutils@1.2.0"],"schemaVersion":1,"symbols":["pvutils.toBase64"]},"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.toBase64"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-pvutils",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-pvutils",
      "version": "1.0.0",
      "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",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of pvutils toBase64 utility",
  "type": "module",
  "main": "src/index.js",
  "dependencies": {
    "pvutils": "1.2.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pvutils.toBase64 in pkg:npm/pvutils@1.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/pvutils@1.2.0"
  ],
  "symbols": [
    "pvutils.toBase64"
  ]
}

import { toBase64 } from 'pvutils';

/**
 * Encode string into BASE64 (or "base64url")
 * @param {string} input
 * @param {boolean} [useUrlTemplate] If "true" then output is encoded using "base64url"
 * @param {boolean} [skipPadding] Skip BASE-64 padding or not
 * @param {boolean} [skipLeadingZeros] Skip leading zeros in input data or not
 * @returns {string}
 */
export function encodeToBase64(input, useUrlTemplate = false, skipPadding = false, skipLeadingZeros = false) {
  return toBase64(input, useUrlTemplate, skipPadding, skipLeadingZeros);
}

export { toBase64 };

import assert from 'node:assert/strict';
import { toBase64, encodeToBase64 } from '../src/index.js';

// 1. toBase64 encodes ASCII strings to standard RFC 4648 Base64 format with proper padding
const text1 = 'Hello, World!';
const expected1 = 'SGVsbG8sIFdvcmxkIQ==';
assert.strictEqual(toBase64(text1), expected1);
assert.strictEqual(encodeToBase64(text1), expected1);

assert.strictEqual(toBase64('M'), 'TQ==');
assert.strictEqual(toBase64('Ma'), 'TWE=');
assert.strictEqual(toBase64('Man'), 'TWFu');

// 2. toBase64 uses URL-safe alphabet characters '-' and '_' when useUrlTemplate is true
const binaryForUrl = '\xfb\xef\xbe';
const stdB64 = toBase64(binaryForUrl, false);
const urlB64 = toBase64(binaryForUrl, true);
assert.strictEqual(stdB64.includes('+') || stdB64.includes('/'), true);
assert.strictEqual(urlB64.includes('-') || urlB64.includes('_'), true);
assert.strictEqual(urlB64.includes('+'), false);
assert.strictEqual(urlB64.includes('/'), false);

// 3. toBase64 omits padding characters when skipPadding is true
const unpadded1 = toBase64('M', false, true);
assert.strictEqual(unpadded1, 'TQ');
assert.strictEqual(unpadded1.endsWith('='), false);

const unpadded2 = toBase64('Ma', false, true);
assert.strictEqual(unpadded2, 'TWE');
assert.strictEqual(unpadded2.endsWith('='), false);

const urlUnpadded = toBase64('Hello, World!', true, true);
assert.strictEqual(urlUnpadded, 'SGVsbG8sIFdvcmxkIQ');
assert.strictEqual(urlUnpadded.endsWith('='), false);

// 4. toBase64 strips leading null characters when skipLeadingZeros is true
const withZeros = '\x00\x00\x00abc';
const withoutZeros = 'abc';
const resultWithSkip = toBase64(withZeros, false, false, true);
const resultWithoutSkip = toBase64(withoutZeros, false, false, false);
assert.strictEqual(resultWithSkip, resultWithoutSkip);
assert.notStrictEqual(toBase64(withZeros, false, false, false), resultWithSkip);

// 5. toBase64 returns an empty string when given an empty string input
assert.strictEqual(toBase64(''), '');

console.log('All pvutils.toBase64 contract assertions passed.');