@tybys/wasm-util 0.10.2: loadSync

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 @tybys/wasm-util.loadSync in pkg:npm/%40tybys/wasm-util@0.10.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40tybys/wasm-util@0.10.2
Demonstrate these symbols/APIs:
  - @tybys/wasm-util.loadSync

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:sha256:02cdc4d43bc0eb68738c31510fe69ff9501876f44a0106a8e3a68fb87cbca861","contract":["loadSync instantiates a WebAssembly binary synchronously from a Uint8Array buffer","loadSync returns an object containing both WebAssembly.Instance and WebAssembly.Module","loadSync instantiates a WebAssembly binary synchronously from an ArrayBuffer source","instantiated WebAssembly module executes exported arithmetic functions correctly","loadSync throws when provided invalid WebAssembly bytecode"],"goal":"verify @tybys/wasm-util.loadSync in pkg:npm/%40tybys/wasm-util@0.10.2","kind":"HOW","packages":["pkg:npm/%40tybys/wasm-util@0.10.2"],"schemaVersion":1,"symbols":["@tybys/wasm-util.loadSync"]},"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/%40tybys/wasm-util@0.10.2"],"schemaVersion":1,"subject":"pkg:npm/%40tybys/wasm-util@0.10.2","symbols":["@tybys/wasm-util.loadSync"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-tybys-wasm-util",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-tybys-wasm-util",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@tybys/wasm-util": "0.10.2"
      }
    },
    "node_modules/@tybys/wasm-util": {
      "version": "0.10.2",
      "resolved": "https://registry.npmjs.org/@tybys/wasm-util/-/wasm-util-0.10.2.tgz",
      "integrity": "sha512-RoBvJ2X0wuKlWFIjrwffGw1IqZHKQqzIchKaadZZfnNpsAYp2mM0h36JtPCjNDAHGgYez/15uMBpfGwchhiMgg==",
      "license": "MIT",
      "dependencies": {
        "tslib": "^2.4.0"
      }
    },
    "node_modules/tslib": {
      "version": "2.8.1",
      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
      "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
      "license": "0BSD"
    }
  }
}

{
  "name": "sample-tybys-wasm-util",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "description": "verify @tybys/wasm-util.loadSync in pkg:npm/@tybys/wasm-util@0.10.2",
  "main": "src/index.mjs",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "@tybys/wasm-util": "0.10.2"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify @tybys/wasm-util.loadSync in pkg:npm/%40tybys/wasm-util@0.10.2",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40tybys/wasm-util@0.10.2"
  ],
  "symbols": [
    "@tybys/wasm-util.loadSync"
  ]
}

import { loadSync } from '@tybys/wasm-util';

export const ADD_WASM_BYTES = new Uint8Array([
  0x00, 0x61, 0x73, 0x6d,
  0x01, 0x00, 0x00, 0x00,
  0x01, 0x07, 0x01, 0x60, 0x02, 0x7f, 0x7f, 0x01, 0x7f,
  0x03, 0x02, 0x01, 0x00,
  0x07, 0x07, 0x01, 0x03, 0x61, 0x64, 0x64, 0x00, 0x00,
  0x0a, 0x09, 0x01, 0x07, 0x00, 0x20, 0x00, 0x20, 0x01, 0x6a, 0x0b
]);

export function loadWasmSync(bufferSource, imports) {
  return loadSync(bufferSource, imports);
}

export function loadAddModule() {
  return loadSync(ADD_WASM_BYTES);
}

export { loadSync };

import assert from 'node:assert';
import {
  loadSync,
  loadWasmSync,
  loadAddModule,
  ADD_WASM_BYTES
} from '../src/index.mjs';

// 1. loadSync instantiates a WebAssembly binary synchronously from a Uint8Array buffer
const { instance, module } = loadSync(ADD_WASM_BYTES);
assert(instance instanceof WebAssembly.Instance, 'instance should be an instance of WebAssembly.Instance');
assert(module instanceof WebAssembly.Module, 'module should be an instance of WebAssembly.Module');

// 2. loadSync returns an object containing both WebAssembly.Instance and WebAssembly.Module
const loaded = loadWasmSync(ADD_WASM_BYTES);
assert(typeof loaded === 'object' && loaded !== null, 'result should be an object');
assert(loaded.instance instanceof WebAssembly.Instance, 'result.instance should be a WebAssembly.Instance');
assert(loaded.module instanceof WebAssembly.Module, 'result.module should be a WebAssembly.Module');

// 3. loadSync instantiates a WebAssembly binary synchronously from an ArrayBuffer source
const arrayBuffer = ADD_WASM_BYTES.buffer.slice(
  ADD_WASM_BYTES.byteOffset,
  ADD_WASM_BYTES.byteOffset + ADD_WASM_BYTES.byteLength
);
const fromBuffer = loadSync(arrayBuffer);
assert(fromBuffer.instance instanceof WebAssembly.Instance, 'instance from ArrayBuffer should be WebAssembly.Instance');
assert(fromBuffer.module instanceof WebAssembly.Module, 'module from ArrayBuffer should be WebAssembly.Module');

// 4. instantiated WebAssembly module executes exported arithmetic functions correctly
assert.strictEqual(typeof instance.exports.add, 'function', 'add export should be a callable function');
assert.strictEqual(instance.exports.add(15, 27), 42, 'add(15, 27) should equal 42');
assert.strictEqual(fromBuffer.instance.exports.add(100, 250), 350, 'fromBuffer add(100, 250) should equal 350');
const helperModule = loadAddModule();
assert.strictEqual(helperModule.instance.exports.add(7, 8), 15, 'helper module add(7, 8) should equal 15');

// 5. loadSync throws when provided invalid WebAssembly bytecode
const invalidBytes = new Uint8Array([0x00, 0x61, 0x73, 0x6d, 0x00, 0x00, 0x00, 0x00]);
assert.throws(
  () => {
    loadSync(invalidBytes);
  },
  (err) => err instanceof WebAssembly.CompileError || err instanceof TypeError || /WebAssembly/.test(err?.message || ''),
  'loadSync should throw a WebAssembly compilation or type error on invalid bytecode'
);

console.log('Contract tests passed successfully.');
process.exit(0);