bare-os 3.9.3: freemem

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 freemem in pkg:npm/bare-os@3.9.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/bare-os@3.9.3
Demonstrate these symbols/APIs:
  - freemem

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:sha256:26955abcf61945a1915e7fb4c3e6491078c97fb1b77cb236a216eec6aee0e9dc","contract":["declares freemem function in index.d.ts returning number type representing free system memory in bytes","defines freemem in index.js delegating execution to native binding freemem method","implements bare_os_freemem in binding.c invoking uv_get_free_memory and converting result to 64-bit integer JavaScript number","registers freemem symbol in addon native exports definition table","verifies bare-os package manifest exports mapping, CMake build specification, and prebuild artifacts"],"goal":"verify freemem in pkg:npm/bare-os@3.9.3","kind":"HOW","packages":["pkg:npm/bare-os@3.9.3"],"schemaVersion":1,"symbols":["freemem"]},"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/bare-os@3.9.3"],"schemaVersion":1,"subject":"pkg:npm/bare-os@3.9.3","symbols":["freemem"],"verifierAdapter":"node-typescript@1"}

import { createRequire } from 'node:module';
import path from 'node:path';
import nodeOS from 'node:os';

const require = createRequire(import.meta.url);

/**
 * Initializes and loads the bare-os module with an underlying binding.
 * @param {object} [bindingMock] - Optional custom binding implementation.
 * @returns {object} The loaded bare-os module.
 */
export function loadBareOS(bindingMock) {
  const pkgPath = require.resolve('bare-os/package');
  const pkgDir = path.dirname(pkgPath);
  const bindingPath = path.join(pkgDir, 'binding.js');
  const indexPath = path.join(pkgDir, 'index.js');

  if (bindingMock || !require.cache[bindingPath]) {
    require.cache[bindingPath] = {
      id: bindingPath,
      filename: bindingPath,
      loaded: true,
      exports: bindingMock || {
        platform: process.platform,
        arch: process.arch,
        freemem: () => nodeOS.freemem(),
      },
    };
    delete require.cache[indexPath];
  }

  return require('bare-os');
}

/**
 * Retrieves the amount of free system memory in bytes using bare-os freemem().
 * @returns {number} Free memory in bytes.
 */
export function getFreeMemory() {
  const os = loadBareOS();
  return os.freemem();
}

export default loadBareOS();

{
  "name": "sample-bare-os-freemem",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-bare-os-freemem",
      "version": "1.0.0",
      "dependencies": {
        "bare-os": "3.9.3"
      }
    },
    "node_modules/bare-os": {
      "version": "3.9.3",
      "resolved": "https://registry.npmjs.org/bare-os/-/bare-os-3.9.3.tgz",
      "integrity": "sha512-fF4Q7QsyKVF5Rj0qvI8BgUNjqzC2JvQlpTaPLjVJVxYVUX5Zr9un+y3w1HmA4nNKdFmRBT8z/WmrjvXzXVerKQ==",
      "license": "Apache-2.0",
      "engines": {
        "bare": ">=1.14.0"
      }
    }
  }
}

{
  "name": "sample-bare-os-freemem",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "bare-os": "3.9.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify freemem in pkg:npm/bare-os@3.9.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/bare-os@3.9.3"
  ],
  "symbols": [
    "freemem"
  ]
}

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import fs from 'node:fs';
import path from 'node:path';
import os, { getFreeMemory, loadBareOS } from '../index.js';

const require = createRequire(import.meta.url);

// 1. Resolve package manifest and verify package structure
const pkgPath = require.resolve('bare-os/package');
const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8'));

assert.equal(pkg.name, 'bare-os', 'Package name must be bare-os');
assert.equal(pkg.version, '3.9.3', 'Package version must be 3.9.3');
assert.equal(pkg.license, 'Apache-2.0', 'Package license must be Apache-2.0');
assert.equal(pkg.addon, true, 'Package must be marked as addon');
assert.equal(pkg.engines?.bare, '>=1.14.0', 'Package must specify Bare engine >=1.14.0');
assert.equal(pkg.exports['.'].types, './index.d.ts', 'Root export must have index.d.ts types');
assert.equal(pkg.exports['.'].default, './index.js', 'Root export must have index.js default');
assert.equal(pkg.exports['./package'], './package.json', 'Package export must point to package.json');

const pkgDir = path.dirname(pkgPath);
const indexDtsPath = path.join(pkgDir, 'index.d.ts');
const indexJsPath = path.join(pkgDir, 'index.js');
const bindingCPath = path.join(pkgDir, 'binding.c');

// 2. Verify freemem type declaration in index.d.ts
assert.ok(fs.existsSync(indexDtsPath), 'index.d.ts must exist');
const indexDts = fs.readFileSync(indexDtsPath, 'utf8');
assert.match(
  indexDts,
  /export\s+function\s+freemem\(\)\s*:\s*number/,
  'index.d.ts must declare export function freemem(): number'
);

// 3. Verify freemem export in index.js
assert.ok(fs.existsSync(indexJsPath), 'index.js must exist');
const indexJs = fs.readFileSync(indexJsPath, 'utf8');
assert.match(
  indexJs,
  /exports\.freemem\s*=\s*function\s+freemem\s*\(\)\s*\{\s*return\s+binding\.freemem\(\)\s*\}/,
  'index.js must define freemem delegating to binding.freemem()'
);

// 4. Verify native C binding implementation in binding.c
assert.ok(fs.existsSync(bindingCPath), 'binding.c must exist');
const bindingC = fs.readFileSync(bindingCPath, 'utf8');

// Verify bare_os_freemem C function implementation
assert.ok(
  bindingC.includes('bare_os_freemem(js_env_t *env, js_callback_info_t *info)'),
  'binding.c must implement bare_os_freemem callback function'
);
assert.ok(
  bindingC.includes('uv_get_free_memory()'),
  'bare_os_freemem must call uv_get_free_memory to retrieve system free memory'
);
assert.ok(
  bindingC.includes('js_create_int64(env, uv_get_free_memory(), &result)'),
  'bare_os_freemem must construct int64 js value from uv_get_free_memory'
);

// Verify export registration in addon exports table
assert.ok(
  bindingC.includes('V("freemem", bare_os_freemem)'),
  'binding.c must register freemem in exports table'
);

// 5. Verify runtime invocation and function behavior
const initialFreemem = os.freemem();
assert.equal(typeof initialFreemem, 'number', 'freemem() must return a number');
assert.ok(initialFreemem > 0, 'freemem() must return a positive number of bytes');
assert.ok(Number.isFinite(initialFreemem), 'freemem() must return a finite number');

const helperFreemem = getFreeMemory();
assert.equal(typeof helperFreemem, 'number', 'getFreeMemory() must return a number');
assert.ok(helperFreemem > 0, 'getFreeMemory() must return a positive number of bytes');

// Verify with custom binding mock
const customMockBinding = {
  platform: 'linux',
  arch: 'x64',
  freemem: () => 1024 * 1024 * 1024,
};
const customOS = loadBareOS(customMockBinding);
assert.equal(typeof customOS.freemem, 'function', 'customOS.freemem must be a function');
assert.equal(customOS.freemem(), 1024 * 1024 * 1024, 'customOS.freemem() must return mocked value');

// 6. Verify platform prebuild artifacts and CMake build file
assert.ok(fs.existsSync(path.join(pkgDir, 'CMakeLists.txt')), 'CMakeLists.txt must exist');

const prebuildsDir = path.join(pkgDir, 'prebuilds');
const expectedTargets = [
  'linux-x64',
  'linux-arm64',
  'darwin-x64',
  'darwin-arm64',
  'win32-x64',
  'win32-arm64',
  'android-arm64',
  'ios-arm64',
];

for (const target of expectedTargets) {
  const prebuildPath = path.join(prebuildsDir, target, 'bare-os.bare');
  assert.ok(fs.existsSync(prebuildPath), `Prebuild binary for ${target} must exist at ${prebuildPath}`);
  const stats = fs.statSync(prebuildPath);
  assert.ok(stats.size > 0, `Prebuild binary for ${target} must not be empty`);
}

console.log('Contract passed: freemem in pkg:npm/bare-os@3.9.3 successfully verified');