bare-os 3.9.3: resourceUsage

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 resourceUsage 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:
  - resourceUsage

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:sha256:7fdb0646eb9eed1f80304afa705ffc01aa5be66c7bc286e9589433da8f15018e","contract":["package manifest exports resourceUsage function signature in TypeScript definitions and requires Bare engine \u003e=1.14.0","bare-os exports resourceUsage in index.js delegating to native binding","index.d.ts declares resourceUsage returning metrics including userCPUTime, systemCPUTime, maxRSS, and context switches","binding.c implements bare_os_resource_usage wrapping libuv uv_getrusage with 16 resource statistics","resource usage validator confirms schema integrity for CPU times, memory metrics, and I/O counts"],"goal":"verify resourceUsage in pkg:npm/bare-os@3.9.3","kind":"HOW","packages":["pkg:npm/bare-os@3.9.3"],"schemaVersion":1,"symbols":["resourceUsage"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/bare-os@3.9.3"],"schemaVersion":1,"subject":"pkg:npm/bare-os@3.9.3","symbols":["resourceUsage"],"verifierAdapter":"node-typescript@1"}

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

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

import fs from 'node:fs';
import path from 'node:path';
import { createRequire } from 'node:module';

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

/**
 * Expected fields in a bare-os resourceUsage result object.
 */
export const RESOURCE_USAGE_FIELDS = Object.freeze([
  'userCPUTime',
  'systemCPUTime',
  'maxRSS',
  'sharedMemorySize',
  'unsharedDataSize',
  'unsharedStackSize',
  'minorPageFault',
  'majorPageFault',
  'swappedOut',
  'fsRead',
  'fsWrite',
  'ipcSent',
  'ipcReceived',
  'signalsCount',
  'voluntaryContextSwitches',
  'involuntaryContextSwitches',
]);

/**
 * Validates that an object conforms to the bare-os resourceUsage schema.
 *
 * @param {unknown} usage - The resource usage object to validate.
 * @returns {boolean} True if all required fields exist and are finite numbers.
 * @throws {TypeError} If usage is not an object or any required field is missing/invalid.
 */
export function validateResourceUsageObject(usage) {
  if (usage === null || typeof usage !== 'object') {
    throw new TypeError(`Resource usage must be an object. Received ${typeof usage}`);
  }

  for (const field of RESOURCE_USAGE_FIELDS) {
    if (typeof usage[field] !== 'number' || !Number.isFinite(usage[field])) {
      throw new TypeError(
        `Field "${field}" in resourceUsage must be a finite number. Received ${typeof usage[field]} (${usage[field]})`
      );
    }
  }

  return true;
}

/**
 * Calculates CPU time delta between two resourceUsage snapshots.
 *
 * @param {object} before - Resource usage snapshot at start.
 * @param {object} after - Resource usage snapshot at end.
 * @returns {{ userCPUTimeDelta: number, systemCPUTimeDelta: number, totalCPUTimeDelta: number }}
 */
export function calculateResourceUsageDelta(before, after) {
  validateResourceUsageObject(before);
  validateResourceUsageObject(after);

  const userCPUTimeDelta = Math.max(0, after.userCPUTime - before.userCPUTime);
  const systemCPUTimeDelta = Math.max(0, after.systemCPUTime - before.systemCPUTime);

  return {
    userCPUTimeDelta,
    systemCPUTimeDelta,
    totalCPUTimeDelta: userCPUTimeDelta + systemCPUTimeDelta,
  };
}

/**
 * Reads bare-os package metadata.
 *
 * @returns {object} The parsed package.json manifest.
 */
export function getBareOsPackage() {
  const pkgPath = require.resolve('bare-os/package');
  return JSON.parse(fs.readFileSync(pkgPath, 'utf8'));
}

/**
 * Reads bare-os package sources and declarations.
 *
 * @returns {{ pkgDir: string, indexJs: string, indexDts: string, bindingC: string }}
 */
export function getBareOsSource() {
  const pkgDir = path.dirname(require.resolve('bare-os/package'));
  const indexJs = fs.readFileSync(path.join(pkgDir, 'index.js'), 'utf8');
  const indexDts = fs.readFileSync(path.join(pkgDir, 'index.d.ts'), 'utf8');
  const bindingC = fs.readFileSync(path.join(pkgDir, 'binding.c'), 'utf8');
  return { pkgDir, indexJs, indexDts, bindingC };
}

/**
 * Inspects bare-os resourceUsage API contract.
 *
 * @returns {{ hasJsExport: boolean, hasTsDeclaration: boolean, hasBindingRegistration: boolean, hasBindingFunction: boolean }}
 */
export function inspectResourceUsageApiContract() {
  const { indexJs, indexDts, bindingC } = getBareOsSource();

  const hasJsExport =
    indexJs.includes('exports.resourceUsage = function resourceUsage()') &&
    indexJs.includes('return binding.resourceUsage()');

  const hasTsDeclaration =
    indexDts.includes('export function resourceUsage(): {') &&
    indexDts.includes('userCPUTime: number') &&
    indexDts.includes('systemCPUTime: number') &&
    indexDts.includes('maxRSS: number') &&
    indexDts.includes('voluntaryContextSwitches: number');

  const hasBindingRegistration = bindingC.includes('V("resourceUsage", bare_os_resource_usage)');
  const hasBindingFunction =
    bindingC.includes('bare_os_resource_usage(') && bindingC.includes('uv_getrusage(&usage)');

  return {
    hasJsExport,
    hasTsDeclaration,
    hasBindingRegistration,
    hasBindingFunction,
  };
}

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import fs from 'node:fs';
import path from 'node:path';
import {
  RESOURCE_USAGE_FIELDS,
  validateResourceUsageObject,
  calculateResourceUsageDelta,
  getBareOsPackage,
  getBareOsSource,
  inspectResourceUsageApiContract,
} from '../src/index.mjs';

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

// 1. Verify bare-os package manifest and metadata
const pkg = getBareOsPackage();
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 requirement');
assert.ok(pkg.exports, 'Package must define exports map');
assert.equal(pkg.exports['.'].types, './index.d.ts', 'Root export must specify index.d.ts types');
assert.equal(pkg.exports['.'].default, './index.js', 'Root export must specify index.js default');

// 2. Verify JavaScript export of resourceUsage in index.js
const { pkgDir, indexJs, indexDts, bindingC } = getBareOsSource();
assert.ok(
  indexJs.includes('exports.resourceUsage = function resourceUsage()'),
  'index.js must export resourceUsage function'
);
assert.ok(
  indexJs.includes('return binding.resourceUsage()'),
  'resourceUsage function in index.js must delegate to native binding.resourceUsage()'
);

// 3. Verify TypeScript declarations for resourceUsage returning all 16 metrics
assert.ok(
  indexDts.includes('export function resourceUsage(): {'),
  'index.d.ts must declare export function resourceUsage(): {'
);
for (const field of RESOURCE_USAGE_FIELDS) {
  assert.ok(
    indexDts.includes(`${field}: number`),
    `index.d.ts must declare ${field}: number in resourceUsage return type`
  );
}

// 4. Verify C native binding implementation for bare_os_resource_usage
assert.ok(
  bindingC.includes('V("resourceUsage", bare_os_resource_usage)'),
  'binding.c must register bare_os_resource_usage under resourceUsage'
);
assert.ok(
  bindingC.includes('bare_os_resource_usage(js_env_t *env, js_callback_info_t *info)'),
  'binding.c must define bare_os_resource_usage function'
);
assert.ok(
  bindingC.includes('uv_getrusage(&usage)'),
  'bare_os_resource_usage must invoke libuv uv_getrusage'
);
assert.ok(
  bindingC.includes('V("userCPUTime", utime)'),
  'bare_os_resource_usage must map userCPUTime'
);
assert.ok(
  bindingC.includes('V("systemCPUTime", stime)'),
  'bare_os_resource_usage must map systemCPUTime'
);
assert.ok(
  bindingC.includes('V("maxRSS", maxrss)'),
  'bare_os_resource_usage must map maxRSS'
);
assert.ok(
  bindingC.includes('V("voluntaryContextSwitches", nvcsw)'),
  'bare_os_resource_usage must map voluntaryContextSwitches'
);
assert.ok(
  bindingC.includes('V("involuntaryContextSwitches", nivcsw)'),
  'bare_os_resource_usage must map involuntaryContextSwitches'
);

// 5. Verify inspection helper
const inspection = inspectResourceUsageApiContract();
assert.equal(inspection.hasJsExport, true, 'inspectResourceUsageApiContract reports JS export present');
assert.equal(inspection.hasTsDeclaration, true, 'inspectResourceUsageApiContract reports TS declaration present');
assert.equal(inspection.hasBindingRegistration, true, 'inspectResourceUsageApiContract reports binding registration present');
assert.equal(inspection.hasBindingFunction, true, 'inspectResourceUsageApiContract reports binding function present');

// 6. Verify JavaScript wrapper delegation with mock binding
const bindingPath = path.join(pkgDir, 'binding.js');
const mockUsage = {
  userCPUTime: 15000,
  systemCPUTime: 5000,
  maxRSS: 32768,
  sharedMemorySize: 0,
  unsharedDataSize: 0,
  unsharedStackSize: 0,
  minorPageFault: 120,
  majorPageFault: 2,
  swappedOut: 0,
  fsRead: 8,
  fsWrite: 16,
  ipcSent: 0,
  ipcReceived: 0,
  signalsCount: 0,
  voluntaryContextSwitches: 45,
  involuntaryContextSwitches: 12,
};

let resourceUsageCalled = false;
require.cache[bindingPath] = {
  id: bindingPath,
  filename: bindingPath,
  loaded: true,
  exports: {
    resourceUsage: () => {
      resourceUsageCalled = true;
      return mockUsage;
    },
    signals: {},
    errnos: {},
    priority: {},
  },
};

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

resourceUsageCalled = false;
const usageResult = bareOs.resourceUsage();
assert.equal(resourceUsageCalled, true, 'bareOs.resourceUsage() must call binding.resourceUsage()');
assert.deepEqual(usageResult, mockUsage, 'bareOs.resourceUsage() must return structure from binding');

// 7. Verify validator and delta calculation helpers
assert.equal(validateResourceUsageObject(mockUsage), true);

const afterUsage = {
  ...mockUsage,
  userCPUTime: 25000,
  systemCPUTime: 8000,
  maxRSS: 35000,
};

const delta = calculateResourceUsageDelta(mockUsage, afterUsage);
assert.equal(delta.userCPUTimeDelta, 10000, 'user CPU delta must be 10000 microseconds');
assert.equal(delta.systemCPUTimeDelta, 3000, 'system CPU delta must be 3000 microseconds');
assert.equal(delta.totalCPUTimeDelta, 13000, 'total CPU delta must be 13000 microseconds');

// Verify validator rejection on invalid data
assert.throws(() => validateResourceUsageObject(null), TypeError);
assert.throws(() => validateResourceUsageObject({ userCPUTime: 'invalid' }), TypeError);
assert.throws(() => validateResourceUsageObject({}), TypeError);

console.log('Contract verification finished successfully for bare-os resourceUsage.');