@webassemblyjs/helper-wasm-bytecode 1.13.2

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 pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2
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:ffe64f7c296cebef072faafe667e740b89bb86721355c5cab665cf5f2985587b","constraints":{"executionContext":"node"},"contract":["magicModuleHeader and moduleVersion define standard WebAssembly binary header constants","sections maps WebAssembly section names to their standard binary section IDs","getSectionForNode resolves WebAssembly AST node types to their corresponding section names","valtypes and valtypesByString provide bidirectional mapping for WebAssembly value type bytecode encodings","symbolsByByte and symbolsByName provide bidirectional instruction opcode lookup and argument metadata"],"goal":"verify pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2","kind":"HOW","packages":["pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2"],"schemaVersion":1},"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/%40webassemblyjs/helper-wasm-bytecode@1.13.2"],"schemaVersion":1,"subject":"pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-webassemblyjs-helper-wasm-bytecode",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-webassemblyjs-helper-wasm-bytecode",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@webassemblyjs/helper-wasm-bytecode": "1.13.2"
      }
    },
    "node_modules/@webassemblyjs/helper-wasm-bytecode": {
      "version": "1.13.2",
      "resolved": "https://registry.npmjs.org/@webassemblyjs/helper-wasm-bytecode/-/helper-wasm-bytecode-1.13.2.tgz",
      "integrity": "sha512-3QbLKy93F0EAIXLh0ogEVR6rOubA9AoZ+WRYhNbFyuB70j3dRdwH9g+qXhLAO0kiYGlg3TxDV+I4rQTr/YNXkA==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-webassemblyjs-helper-wasm-bytecode",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room code sample for @webassemblyjs/helper-wasm-bytecode@1.13.2",
  "main": "src/index.js",
  "license": "MIT-0",
  "dependencies": {
    "@webassemblyjs/helper-wasm-bytecode": "1.13.2"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40webassemblyjs/helper-wasm-bytecode@1.13.2"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

'use strict';

const wasmBytecodeModule = require('@webassemblyjs/helper-wasm-bytecode');

const bytecode = wasmBytecodeModule.default || wasmBytecodeModule;
const getSectionForNode = wasmBytecodeModule.getSectionForNode || bytecode.getSectionForNode;

/**
 * Validates whether the given binary buffer begins with the standard WASM magic header and version.
 *
 * @param {Uint8Array|Array<number>} headerBytes
 * @returns {boolean}
 */
function isValidWasmHeader(headerBytes) {
  if (!headerBytes || headerBytes.length < 8) {
    return false;
  }
  const magic = bytecode.magicModuleHeader;
  const version = bytecode.moduleVersion;

  for (let i = 0; i < 4; i++) {
    if (headerBytes[i] !== magic[i]) return false;
  }
  for (let i = 0; i < 4; i++) {
    if (headerBytes[4 + i] !== version[i]) return false;
  }
  return true;
}

/**
 * Returns the numeric section ID for a given section name.
 *
 * @param {string} sectionName
 * @returns {number|undefined}
 */
function getSectionId(sectionName) {
  return bytecode.sections[sectionName];
}

/**
 * Resolves the section name for an AST node using getSectionForNode.
 *
 * @param {object} astNode
 * @returns {string|undefined}
 */
function resolveSectionForNode(astNode) {
  return getSectionForNode(astNode);
}

/**
 * Look up opcode bytecode number for an instruction name (e.g. 'i32.add' or 'nop').
 *
 * @param {string} instructionName
 * @returns {number|undefined}
 */
function getOpcodeByte(instructionName) {
  const byteStr = bytecode.symbolsByName[instructionName];
  return byteStr !== undefined ? Number(byteStr) : undefined;
}

/**
 * Look up instruction symbol information for an opcode byte (e.g. 0x6a -> { name: 'add', object: 'i32', numberOfArgs: 0 }).
 *
 * @param {number} opcodeByte
 * @returns {object|undefined}
 */
function getInstructionSymbol(opcodeByte) {
  return bytecode.symbolsByByte[opcodeByte];
}

/**
 * Look up value type string by its binary bytecode byte (e.g. 0x7f -> 'i32').
 *
 * @param {number} typeByte
 * @returns {string|undefined}
 */
function getValtypeName(typeByte) {
  return bytecode.valtypes[typeByte];
}

/**
 * Look up value type byte number by its type name (e.g. 'i32' -> 0x7f).
 *
 * @param {string} typeName
 * @returns {number|undefined}
 */
function getValtypeByte(typeName) {
  const byteStr = bytecode.valtypesByString[typeName];
  return byteStr !== undefined ? Number(byteStr) : undefined;
}

module.exports = {
  bytecode,
  getSectionForNode,
  isValidWasmHeader,
  getSectionId,
  resolveSectionForNode,
  getOpcodeByte,
  getInstructionSymbol,
  getValtypeName,
  getValtypeByte
};

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const {
  bytecode,
  getSectionForNode,
  isValidWasmHeader,
  getSectionId,
  resolveSectionForNode,
  getOpcodeByte,
  getInstructionSymbol,
  getValtypeName,
  getValtypeByte
} = require('../src/index.js');

async function testAll() {
  // 1. magicModuleHeader and moduleVersion define standard WebAssembly binary header constants
  assert.deepEqual(bytecode.magicModuleHeader, [0x00, 0x61, 0x73, 0x6d]);
  assert.deepEqual(bytecode.moduleVersion, [0x01, 0x00, 0x00, 0x00]);

  const validHeader = new Uint8Array([0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00]);
  assert.equal(isValidWasmHeader(validHeader), true);

  const invalidMagic = new Uint8Array([0x7f, 0x45, 0x4c, 0x46, 0x01, 0x00, 0x00, 0x00]);
  assert.equal(isValidWasmHeader(invalidMagic), false);

  const invalidVersion = new Uint8Array([0x00, 0x61, 0x73, 0x6d, 0x02, 0x00, 0x00, 0x00]);
  assert.equal(isValidWasmHeader(invalidVersion), false);

  assert.equal(isValidWasmHeader(new Uint8Array([0x00, 0x61, 0x73])), false);

  // 2. sections maps WebAssembly section names to their standard binary section IDs
  assert.equal(getSectionId('custom'), 0);
  assert.equal(getSectionId('type'), 1);
  assert.equal(getSectionId('import'), 2);
  assert.equal(getSectionId('func'), 3);
  assert.equal(getSectionId('table'), 4);
  assert.equal(getSectionId('memory'), 5);
  assert.equal(getSectionId('global'), 6);
  assert.equal(getSectionId('export'), 7);
  assert.equal(getSectionId('start'), 8);
  assert.equal(getSectionId('element'), 9);
  assert.equal(getSectionId('code'), 10);
  assert.equal(getSectionId('data'), 11);
  assert.equal(getSectionId('nonexistent'), undefined);

  assert.equal(bytecode.sections.custom, 0);
  assert.equal(bytecode.sections.type, 1);
  assert.equal(bytecode.sections.import, 2);
  assert.equal(bytecode.sections.func, 3);
  assert.equal(bytecode.sections.table, 4);
  assert.equal(bytecode.sections.memory, 5);
  assert.equal(bytecode.sections.global, 6);
  assert.equal(bytecode.sections.export, 7);
  assert.equal(bytecode.sections.start, 8);
  assert.equal(bytecode.sections.element, 9);
  assert.equal(bytecode.sections.code, 10);
  assert.equal(bytecode.sections.data, 11);

  // 3. getSectionForNode resolves WebAssembly AST node types to their corresponding section names
  assert.equal(resolveSectionForNode({ type: 'ModuleImport' }), 'import');
  assert.equal(resolveSectionForNode({ type: 'Func' }), 'code');
  assert.equal(resolveSectionForNode({ type: 'Instr' }), 'code');
  assert.equal(resolveSectionForNode({ type: 'CallInstruction' }), 'code');
  assert.equal(resolveSectionForNode({ type: 'CallIndirectInstruction' }), 'code');
  assert.equal(resolveSectionForNode({ type: 'ModuleExport' }), 'export');
  assert.equal(resolveSectionForNode({ type: 'Start' }), 'start');
  assert.equal(resolveSectionForNode({ type: 'TypeInstruction' }), 'type');
  assert.equal(resolveSectionForNode({ type: 'IndexInFuncSection' }), 'func');
  assert.equal(resolveSectionForNode({ type: 'Global' }), 'global');
  assert.equal(resolveSectionForNode({ type: 'Program' }), undefined);
  assert.equal(resolveSectionForNode({ type: 'Unknown' }), undefined);

  assert.equal(getSectionForNode({ type: 'ModuleImport' }), 'import');
  assert.equal(getSectionForNode({ type: 'Func' }), 'code');

  // 4. valtypes and valtypesByString provide bidirectional mapping for WebAssembly value type bytecode encodings
  assert.equal(getValtypeName(0x7f), 'i32');
  assert.equal(getValtypeName(0x7e), 'i64');
  assert.equal(getValtypeName(0x7d), 'f32');
  assert.equal(getValtypeName(0x7c), 'f64');
  assert.equal(getValtypeName(0x7b), 'v128');
  assert.equal(getValtypeName(0x70), 'anyfunc');
  assert.equal(getValtypeName(0x6f), 'externref');

  assert.equal(getValtypeByte('i32'), 0x7f);
  assert.equal(getValtypeByte('i64'), 0x7e);
  assert.equal(getValtypeByte('f32'), 0x7d);
  assert.equal(getValtypeByte('f64'), 0x7c);
  assert.equal(getValtypeByte('v128'), 0x7b);
  assert.equal(getValtypeByte('anyfunc'), 0x70);
  assert.equal(getValtypeByte('externref'), 0x6f);

  assert.equal(bytecode.types.func, 0x60);
  assert.equal(bytecode.types.result, 0x40);
  assert.equal(bytecode.exportTypes[0x00], 'Func');
  assert.equal(bytecode.exportTypes[0x01], 'Table');
  assert.equal(bytecode.exportTypes[0x02], 'Memory');
  assert.equal(bytecode.exportTypes[0x03], 'Global');
  assert.equal(bytecode.globalTypes[0], 'const');
  assert.equal(bytecode.globalTypes[1], 'var');

  // 5. symbolsByByte and symbolsByName provide bidirectional instruction opcode lookup and argument metadata
  assert.equal(getOpcodeByte('i32.const'), 0x41);
  assert.equal(bytecode.symbolsByName['i32.const'], '65');
  assert.deepEqual(getInstructionSymbol(0x41), { name: 'const', object: 'i32', numberOfArgs: 1 });

  assert.equal(getOpcodeByte('i32.add'), 0x6a);
  assert.equal(bytecode.symbolsByName['i32.add'], '106');
  assert.deepEqual(getInstructionSymbol(0x6a), { name: 'add', object: 'i32', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('end'), 0x0b);
  assert.equal(bytecode.symbolsByName['end'], '11');
  assert.deepEqual(getInstructionSymbol(0x0b), { name: 'end', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('unreachable'), 0x00);
  assert.equal(bytecode.symbolsByName['unreachable'], '0');
  assert.deepEqual(getInstructionSymbol(0x00), { name: 'unreachable', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('nop'), 0x01);
  assert.equal(bytecode.symbolsByName['nop'], '1');
  assert.deepEqual(getInstructionSymbol(0x01), { name: 'nop', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('block'), 0x02);
  assert.equal(bytecode.symbolsByName['block'], '2');
  assert.deepEqual(getInstructionSymbol(0x02), { name: 'block', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('loop'), 0x03);
  assert.equal(bytecode.symbolsByName['loop'], '3');
  assert.deepEqual(getInstructionSymbol(0x03), { name: 'loop', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('if'), 0x04);
  assert.equal(bytecode.symbolsByName['if'], '4');
  assert.deepEqual(getInstructionSymbol(0x04), { name: 'if', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('call'), 0x10);
  assert.equal(bytecode.symbolsByName['call'], '16');
  assert.deepEqual(getInstructionSymbol(0x10), { name: 'call', numberOfArgs: 1 });

  assert.equal(getOpcodeByte('drop'), 0x1a);
  assert.equal(bytecode.symbolsByName['drop'], '26');
  assert.deepEqual(getInstructionSymbol(0x1a), { name: 'drop', numberOfArgs: 0 });

  assert.equal(getOpcodeByte('get_local'), 0x20);
  assert.equal(bytecode.symbolsByName['get_local'], '32');
  assert.deepEqual(getInstructionSymbol(0x20), { name: 'get_local', numberOfArgs: 1 });

  assert.equal(getOpcodeByte('set_local'), 0x21);
  assert.equal(bytecode.symbolsByName['set_local'], '33');
  assert.deepEqual(getInstructionSymbol(0x21), { name: 'set_local', numberOfArgs: 1 });
}

testAll()
  .then(() => {
    console.log('All contract assertions passed successfully.');
    process.exit(0);
  })
  .catch((err) => {
    console.error('Contract assertion failed:', err);
    process.exit(1);
  });