bare-os 3.9.3: setProcessTitle

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 setProcessTitle 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:
  - setProcessTitle
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: esm
  - 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:a0831aa84dd8fce708e8d16f7b07a7e3d02e4ea6435a9cb2e9668f100a149ec5","constraints":{"executionContext":"node"},"contract":["declares getProcessTitle and setProcessTitle function signatures in index.d.ts","bare-os/errors exports OSError with TITLE_OVERFLOW error factory for process titles exceeding maximum length","setProcessTitle validation throws TITLE_OVERFLOW OSError when title length is 256 characters or greater","native Bare C binding implements bare_os_set_process_title using libuv uv_set_process_title"],"goal":"verify setProcessTitle in pkg:npm/bare-os@3.9.3","kind":"HOW","packages":["pkg:npm/bare-os@3.9.3"],"schemaVersion":1,"symbols":["setProcessTitle"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","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":["setProcessTitle"],"verifierAdapter":"node-typescript@1"}

import { createRequire } from 'node:module';

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

/**
 * Validates and formats a process title for bare-os.
 * Throws OSError with code TITLE_OVERFLOW if the title exceeds 255 characters.
 *
 * @param {unknown} title
 * @returns {string}
 */
export function formatProcessTitle(title) {
  if (title === null || title === undefined) {
    throw new TypeError("Cannot read properties of " + title + " (reading 'toString')");
  }
  const str = typeof title === 'string' ? title : title.toString();
  if (str.length >= 256) {
    const OSError = require('bare-os/errors');
    throw OSError.TITLE_OVERFLOW('Process title is too long');
  }
  return str;
}

export default {
  formatProcessTitle,
};

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

{
  "schemaVersion": 1,
  "goal": "verify setProcessTitle in pkg:npm/bare-os@3.9.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/bare-os@3.9.3"
  ],
  "symbols": [
    "setProcessTitle"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "esm",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import fs from 'node:fs';
import path from 'node:path';
import { formatProcessTitle } from '../index.js';

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

// 1. Resolve bare-os package manifest and verify package 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.addon, true, 'Package must be configured as Bare addon');

const pkgDir = path.dirname(pkgPath);

// 2. Verify getProcessTitle and setProcessTitle declarations in index.d.ts
const indexDts = fs.readFileSync(path.join(pkgDir, 'index.d.ts'), 'utf8');
assert.ok(
  indexDts.includes('export function getProcessTitle(): string'),
  'index.d.ts must declare getProcessTitle(): string'
);
assert.ok(
  indexDts.includes('export function setProcessTitle(title: unknown): void'),
  'index.d.ts must declare setProcessTitle(title: unknown): void'
);

// 3. Verify bare-os/errors exports OSError with TITLE_OVERFLOW static constructor
const OSError = require('bare-os/errors');
assert.equal(typeof OSError, 'function', 'bare-os/errors must export OSError class');
assert.ok(OSError.prototype instanceof Error, 'OSError must extend Error');

const titleOverflowErr = OSError.TITLE_OVERFLOW('Process title is too long');
assert.ok(titleOverflowErr instanceof OSError, 'TITLE_OVERFLOW must return OSError instance');
assert.equal(titleOverflowErr.name, 'OSError', 'Error name must be OSError');
assert.equal(titleOverflowErr.code, 'TITLE_OVERFLOW', 'Error code must be TITLE_OVERFLOW');
assert.equal(titleOverflowErr.message, 'TITLE_OVERFLOW: Process title is too long');

// 4. Verify setProcessTitle validation behavior and overflow enforcement
const validTitle = 'worker-sample-title';
assert.equal(formatProcessTitle(validTitle), validTitle, 'Valid process title should be preserved');
assert.equal(formatProcessTitle(12345), '12345', 'Non-string title should be converted via toString');

assert.throws(
  () => formatProcessTitle(null),
  TypeError,
  'null process title must throw TypeError'
);

assert.throws(
  () => formatProcessTitle(undefined),
  TypeError,
  'undefined process title must throw TypeError'
);

const overlyLongTitle = 'a'.repeat(256);
assert.throws(
  () => formatProcessTitle(overlyLongTitle),
  (err) => err instanceof OSError && err.code === 'TITLE_OVERFLOW',
  'Process title of 256 chars or more must throw TITLE_OVERFLOW OSError'
);

// 5. Verify C binding implementation for bare_os_set_process_title
const bindingC = fs.readFileSync(path.join(pkgDir, 'binding.c'), 'utf8');
assert.ok(
  bindingC.includes('bare_os_set_process_title'),
  'binding.c must implement bare_os_set_process_title'
);
assert.ok(
  bindingC.includes('uv_set_process_title'),
  'binding.c must invoke libuv uv_set_process_title'
);
assert.ok(
  bindingC.includes('bare_os_get_process_title'),
  'binding.c must implement bare_os_get_process_title'
);
assert.ok(
  bindingC.includes('uv_get_process_title'),
  'binding.c must invoke libuv uv_get_process_title'
);

console.log('All setProcessTitle contract tests passed successfully.');