fflate 0.8.3: strFromU8

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 fflate.strFromU8 in pkg:npm/fflate@0.8.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/fflate@0.8.3
Demonstrate these symbols/APIs:
  - fflate.strFromU8

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:sha256:7e73b4823634d716db40af2fd8ed8427207a1c420bffa459228124557eedc499","contract":["assert strFromU8 decodes ASCII Uint8Array into matching string","assert strFromU8 decodes multi-byte UTF-8 bytes correctly","assert strFromU8 decodes binary data in Latin-1 mode when latin1 is true","assert strFromU8 returns empty string for empty Uint8Array","assert strFromU8 round-trips with strToU8 for unicode text","assert strFromU8 handles long byte sequences without error"],"goal":"verify fflate.strFromU8 in pkg:npm/fflate@0.8.3","kind":"HOW","packages":["pkg:npm/fflate@0.8.3"],"schemaVersion":1,"symbols":["fflate.strFromU8"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/fflate@0.8.3"],"schemaVersion":1,"subject":"pkg:npm/fflate@0.8.3","symbols":["fflate.strFromU8"],"verifierAdapter":"node-typescript@1"}

import { strFromU8, strToU8 } from 'fflate';

/**
 * Converts a Uint8Array to a string.
 *
 * @param {Uint8Array} dat - The bytes to decode.
 * @param {boolean} [latin1=false] - Whether to decode as Latin-1 instead of UTF-8.
 * @returns {string} The decoded string.
 */
export function decodeBytes(dat, latin1) {
  return strFromU8(dat, latin1);
}

export { strFromU8, strToU8 };
export default strFromU8;

{
  "name": "sample-fflate-strfromu8",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-fflate-strfromu8",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "fflate": "0.8.3"
      }
    },
    "node_modules/fflate": {
      "version": "0.8.3",
      "resolved": "https://registry.npmjs.org/fflate/-/fflate-0.8.3.tgz",
      "integrity": "sha512-tbZNuJrLwGUp3zshBtdy4W+ORxZuIh8a5ilyIEQDC5rY1f3U20JMry0Ll3WBzU58EZKsEuJFXhb5gwv8CsPvgA==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-fflate-strfromu8",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "fflate": "0.8.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify fflate.strFromU8 in pkg:npm/fflate@0.8.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/fflate@0.8.3"
  ],
  "symbols": [
    "fflate.strFromU8"
  ]
}

import assert from 'node:assert/strict';
import { strFromU8, strToU8, decodeBytes } from '../index.mjs';

// 1. assert strFromU8 decodes ASCII Uint8Array into matching string
{
  const asciiBytes = new Uint8Array([72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33]);
  const result = decodeBytes(asciiBytes);
  assert.strictEqual(typeof result, 'string');
  assert.strictEqual(result, 'Hello, world!');
}

// 2. assert strFromU8 decodes multi-byte UTF-8 bytes correctly
{
  const utf8Bytes = new TextEncoder().encode('Hello 🌍 UTF-8: äöü, こんにちは, 🚀');
  const result = strFromU8(utf8Bytes);
  assert.strictEqual(result, 'Hello 🌍 UTF-8: äöü, こんにちは, 🚀');
}

// 3. assert strFromU8 decodes binary data in Latin-1 mode when latin1 is true
{
  const latin1Bytes = new Uint8Array([0x00, 0x7F, 0x80, 0xC0, 0xFF]);
  const result = decodeBytes(latin1Bytes, true);
  assert.strictEqual(result.length, 5);
  for (let i = 0; i < latin1Bytes.length; i++) {
    assert.strictEqual(result.charCodeAt(i), latin1Bytes[i]);
  }
}

// 4. assert strFromU8 returns empty string for empty Uint8Array
{
  const emptyBytes = new Uint8Array(0);
  const result = strFromU8(emptyBytes);
  assert.strictEqual(result, '');
  const emptyLatin1 = strFromU8(emptyBytes, true);
  assert.strictEqual(emptyLatin1, '');
}

// 5. assert strFromU8 round-trips with strToU8 for unicode text
{
  const original = 'CodeSampleX verification testing fflate.strFromU8 — Special characters: © ® ™ § ¶ € ¥ £';
  const encoded = strToU8(original);
  assert.ok(encoded instanceof Uint8Array);
  const decoded = decodeBytes(encoded);
  assert.strictEqual(decoded, original);
}

// 6. assert strFromU8 handles long byte sequences without error
{
  const longString = 'abcXYZ1234567890!@#$%^&*()_+'.repeat(1000);
  const longBytes = strToU8(longString);
  const decoded = strFromU8(longBytes);
  assert.strictEqual(decoded, longString);
}

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