bare-os 3.9.3: availableParallelism

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 bare-os.availableParallelism 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:
  - bare-os.availableParallelism

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:cf0382249b0f9ba97e4819bf07ab700dda4b68642cb23e821b1add0c6e960d98","contract":["bare-os package manifest exports root module with availableParallelism API and index.d.ts type declarations","index.d.ts declares availableParallelism function returning number representing logical CPU parallelism","index.js exports availableParallelism function that delegates to native binding availableParallelism","bare_os_available_parallelism in binding.c invokes uv_available_parallelism and returns uint32 to JavaScript","registers availableParallelism symbol in addon native exports definition table","availableParallelism returns a positive integer greater than or equal to 1","availableParallelism executes deterministically and idempotently across multiple invocations","custom parallelism levels configured on native binding reflect accurately through availableParallelism"],"goal":"verify bare-os.availableParallelism in pkg:npm/bare-os@3.9.3","kind":"HOW","packages":["pkg:npm/bare-os@3.9.3"],"schemaVersion":1,"symbols":["bare-os.availableParallelism"]},"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":["bare-os.availableParallelism"],"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);

// Ensure native binding is provided in Node.js environments where require.addon is absent
if (typeof Bare === 'undefined') {
  const mockBinding = {
    platform: process.platform,
    arch: process.arch,
    type() { return nodeOS.type(); },
    version() { return nodeOS.version ? nodeOS.version() : nodeOS.release(); },
    release() { return nodeOS.release(); },
    machine() { return nodeOS.machine ? nodeOS.machine() : process.arch; },
    execPath() { return process.execPath; },
    pid() { return process.pid; },
    ppid() { return process.ppid; },
    cwd() { return process.cwd(); },
    chdir(dir) { process.chdir(dir); },
    tmpdir() { return nodeOS.tmpdir(); },
    homedir() { return nodeOS.homedir(); },
    hostname() { return nodeOS.hostname(); },
    userInfo(uid) { return nodeOS.userInfo(); },
    groupInfo(gid) { return null; },
    networkInterfaces() {
      const ifaces = nodeOS.networkInterfaces();
      const result = [];
      for (const [name, addrs] of Object.entries(ifaces)) {
        if (addrs) {
          for (const addr of addrs) {
            result.push({ name, ...addr });
          }
        }
      }
      return result;
    },
    kill(pid, sig) { process.kill(pid, sig); },
    isLittleEndian: nodeOS.endianness() === 'LE',
    availableParallelism() { return nodeOS.availableParallelism ? nodeOS.availableParallelism() : nodeOS.cpus().length; },
    cpuUsage() { return process.cpuUsage(); },
    threadCpuUsage() { return process.cpuUsage(); },
    resourceUsage() { return process.resourceUsage ? process.resourceUsage() : {}; },
    memoryUsage() { return process.memoryUsage(); },
    freemem() { return nodeOS.freemem(); },
    totalmem() { return nodeOS.totalmem(); },
    availableMemory() { return typeof nodeOS.freemem === 'function' ? nodeOS.freemem() : 0; },
    constrainedMemory() { return 0; },
    uptime() { return nodeOS.uptime(); },
    loadavg() { return nodeOS.loadavg(); },
    cpus() { return nodeOS.cpus(); },
    getProcessTitle() { return process.title; },
    setProcessTitle(t) { process.title = t; },
    getPriority(pid) { return nodeOS.getPriority ? nodeOS.getPriority(pid) : 0; },
    setPriority(pid, p) { if (nodeOS.setPriority) nodeOS.setPriority(pid, p); },
    getEnvKeys() { return Object.keys(process.env); },
    getEnv(n) { return process.env[n]; },
    hasEnv(n) { return Object.prototype.hasOwnProperty.call(process.env, n); },
    setEnv(n, v) { process.env[n] = v; },
    unsetEnv(n) { delete process.env[n]; }
  };

  try {
    const mainPath = require.resolve('bare-os');
    const bindingPath = path.join(path.dirname(mainPath), 'binding.js');
    require.cache[bindingPath] = {
      id: bindingPath,
      filename: bindingPath,
      loaded: true,
      exports: mockBinding
    };
  } catch (err) {
    // node_modules might not be resolved if uninstalled
  }
}

const os = require('bare-os');

/**
 * Returns the number of logical CPU cores available for parallel execution.
 * @returns {number}
 */
export function getAvailableParallelism() {
  return os.availableParallelism();
}

/**
 * Validates that available parallelism is a positive integer.
 * @returns {boolean}
 */
export function hasValidParallelism() {
  const count = os.availableParallelism();
  return typeof count === 'number' && Number.isInteger(count) && count > 0;
}

export default os;

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

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

import assert from "node:assert/strict";
import { createRequire } from "node:module";
import fs from "node:fs";
import path from "node:path";
import os, { getAvailableParallelism, hasValidParallelism } from "../index.js";

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["./constants"]?.types, "./lib/constants.d.ts", "Constants export must have constants.d.ts types");
assert.equal(pkg.exports["./constants"]?.default, "./lib/constants.js", "Constants export must have constants.js default");
assert.equal(pkg.exports["./errors"]?.types, "./lib/errors.d.ts", "Errors export must have errors.d.ts types");
assert.equal(pkg.exports["./errors"]?.default, "./lib/errors.js", "Errors export must have errors.js default");
assert.equal(pkg.exports["./package"], "./package.json", "Package export must point to package.json");

const pkgDir = path.dirname(pkgPath);
const indexDts = fs.readFileSync(path.join(pkgDir, "index.d.ts"), "utf8");
const indexJs = fs.readFileSync(path.join(pkgDir, "index.js"), "utf8");
const bindingC = fs.readFileSync(path.join(pkgDir, "binding.c"), "utf8");

// 2. Verify availableParallelism symbol declarations in TypeScript definition
assert.ok(
  indexDts.includes("export function availableParallelism(): number"),
  "index.d.ts must declare export function availableParallelism(): number"
);

// 3. Verify availableParallelism implementation in JavaScript module
assert.ok(
  indexJs.includes("exports.availableParallelism = function availableParallelism"),
  "index.js must export availableParallelism function"
);
assert.ok(
  indexJs.includes("return binding.availableParallelism()"),
  "availableParallelism function must delegate to binding.availableParallelism()"
);

// 4. Verify C binding implementation and uv_available_parallelism call
assert.ok(
  bindingC.includes("bare_os_available_parallelism"),
  "binding.c must implement bare_os_available_parallelism"
);
assert.ok(
  bindingC.includes("uv_available_parallelism()"),
  "bare_os_available_parallelism must invoke uv_available_parallelism()"
);

// 5. Verify availableParallelism symbol registration in addon exports table
assert.ok(
  bindingC.includes("V(\"availableParallelism\", bare_os_available_parallelism)"),
  "binding.c must register availableParallelism export"
);

// 6. Verify availableParallelism return value and types
assert.equal(typeof os.availableParallelism, "function", "bare-os must export availableParallelism function");
const parallelism = os.availableParallelism();
assert.equal(typeof parallelism, "number", "availableParallelism() must return a number");
assert.ok(Number.isInteger(parallelism), "availableParallelism() must return an integer");
assert.ok(parallelism >= 1, "availableParallelism() must return a positive integer >= 1");

// Helper function tests
assert.equal(getAvailableParallelism(), parallelism, "getAvailableParallelism() must match os.availableParallelism()");
assert.equal(hasValidParallelism(), true, "hasValidParallelism() must return true");

// 7. Verify deterministic and idempotent execution across multiple calls
const firstCall = os.availableParallelism();
const secondCall = os.availableParallelism();
const thirdCall = os.availableParallelism();
assert.equal(firstCall, secondCall, "repeated calls to availableParallelism must return identical values");
assert.equal(secondCall, thirdCall, "repeated calls to availableParallelism must remain stable");

// 8. Verify custom binding parallelism values reflect through API
const bindingFilePath = path.join(pkgDir, "binding.js");
const testValues = [1, 2, 4, 8, 16, 32, 64, 128];
for (const val of testValues) {
  require.cache[bindingFilePath].exports.availableParallelism = () => val;
  assert.equal(os.availableParallelism(), val, `availableParallelism() must return ${val}`);
}

console.log("Contract verification finished successfully.");