bare-os 3.9.3: availableMemory

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 availableMemory 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:
  - availableMemory

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:d003e08a5c71a4fa90299f679afae250c740090863de62b0a062a65dfebb6533","contract":["bare-os package manifest exports root module with availableMemory API and index.d.ts type declarations","index.d.ts declares availableMemory returning a number representing available system memory in bytes","index.js exports availableMemory function delegating to native binding availableMemory call","native binding.c implements bare_os_available_memory using uv_get_available_memory and registers availableMemory export","bare-os availableMemory returns a non-negative number when executed with the addon runtime binding"],"goal":"verify availableMemory in pkg:npm/bare-os@3.9.3","kind":"HOW","packages":["pkg:npm/bare-os@3.9.3"],"schemaVersion":1,"symbols":["availableMemory"]},"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":["availableMemory"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-bare-os-available-memory",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-bare-os-available-memory",
      "version": "1.0.0",
      "license": "MIT-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-available-memory",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "bare-os": "3.9.3"
  }
}

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

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

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

// 1. Resolve bare-os package manifest and verify exports and metadata
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.ok(pkg.exports, 'Package must define exports');
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);

// 2. Verify index.d.ts type declarations for availableMemory
const indexDts = fs.readFileSync(path.join(pkgDir, 'index.d.ts'), 'utf8');
assert.ok(
  indexDts.includes('export function availableMemory(): number'),
  'index.d.ts must declare availableMemory(): number'
);
assert.ok(
  indexDts.includes('export function freemem(): number'),
  'index.d.ts must declare freemem(): number'
);
assert.ok(
  indexDts.includes('export function totalmem(): number'),
  'index.d.ts must declare totalmem(): number'
);

// 3. Verify index.js implementation delegates availableMemory to binding
const indexJs = fs.readFileSync(path.join(pkgDir, 'index.js'), 'utf8');
assert.ok(
  indexJs.includes('exports.availableMemory = function availableMemory() {'),
  'index.js must define exports.availableMemory function'
);
assert.ok(
  indexJs.includes('return binding.availableMemory()'),
  'availableMemory must delegate to binding.availableMemory()'
);

// 4. Verify native binding.c implementation and export registration
const bindingC = fs.readFileSync(path.join(pkgDir, 'binding.c'), 'utf8');
assert.ok(
  bindingC.includes('bare_os_available_memory'),
  'binding.c must contain bare_os_available_memory implementation'
);
assert.ok(
  bindingC.includes('uv_get_available_memory()'),
  'bare_os_available_memory must invoke uv_get_available_memory()'
);
assert.ok(
  bindingC.includes('js_create_int64(env, uv_get_available_memory(), &result)'),
  'bare_os_available_memory must return 64-bit integer JS value'
);
assert.ok(
  bindingC.includes('V("availableMemory", bare_os_available_memory)'),
  'binding.c must register availableMemory in export table'
);

// 5. Verify availableMemory execution behavior with addon runtime binding
let mockAvailableMem = 16 * 1024 * 1024 * 1024;
const mockBinding = {
  platform: 'linux',
  arch: 'x64',
  signals: { SIGINT: 2, SIGTERM: 15 },
  errnos: { ENOENT: 2 },
  priority: { PRIORITY_NORMAL: 0 },
  availableMemory: () => mockAvailableMem,
  freemem: () => 8 * 1024 * 1024 * 1024,
  totalmem: () => 32 * 1024 * 1024 * 1024
};

const originalLoad = Module._load;
Module._load = function(request, parent, isMain) {
  if (request.includes('binding') && parent && parent.filename && parent.filename.includes('bare-os')) {
    return mockBinding;
  }
  return originalLoad.apply(this, arguments);
};

const bareOs = require('bare-os');
assert.equal(typeof bareOs.availableMemory, 'function', 'bare-os must export availableMemory function');

const result1 = bareOs.availableMemory();
assert.equal(typeof result1, 'number', 'availableMemory must return a number');
assert.ok(result1 >= 0, 'availableMemory must be non-negative');
assert.equal(result1, 16 * 1024 * 1024 * 1024, 'availableMemory must return value from binding');

mockAvailableMem = 8 * 1024 * 1024 * 1024;
assert.equal(bareOs.availableMemory(), 8 * 1024 * 1024 * 1024, 'availableMemory must dynamically reflect memory');