{ "name": "node-exec-with-api", "version": "1.0.0", "description": "A Node.js executable (CLI) that also exposes an HTTP API. Includes basic math and utility endpoints.", "main": "bin/cli.js", "bin": { "node-exec-api": "./bin/cli.js" }, "scripts": { "start": "node ./bin/cli.js start", "test": "node ./bin/cli.js help" }, "keywords": [ "cli", "http", "api", "executable" ], "author": "", "license": "MIT" } #!/usr/bin/env node // Small CLI entry that delegates to src/cli.js // Keep this file minimal to act as executable entrypoint. const path = require('path'); const cli = require(path.join('..', 'src', 'cli.js')); // Hand control to the CLI handler cli.main(process.argv.slice(2)).catch(err => { console.error('Unexpected error:', err && err.stack ? err.stack : err); process.exit(1); }); // CLI implementation (no external deps) // Supports: // start [--port ] - start HTTP API server // factorial - compute factorial locally // compute - compute operation locally (op & args) // help - show help const path = require('path'); const server = require(path.join(__dirname, 'server.js')); const math = require(path.join(__dirname, 'math.js')); function printHelp() { console.log([ 'Usage:', ' start [--port ] Start the HTTP API server (default port 3000)', ' factorial Compute factorial of n (prints result)', ' compute Compute operation locally. Example:', ' compute \'{"op":"add","args":[1,2,3]}\'', ' help Show this help message', '', 'Examples:', ' node ./bin/cli.js start --port 4000', ' node ./bin/cli.js factorial 20', ' node ./bin/cli.js compute \'{"op":"mul","args":[2,3,4]}\'' ].join('\n')); } function parsePortOption(args) { for (let i = 0; i < args.length; i++) { const a = args[i]; if (a === '--port' || a === '-p') { const next = args[i + 1]; if (!next) return null; const port = Number(next); if (Number.isInteger(port) && port > 0 && port <= 65535) return port; return null; } else if (a.startsWith('--port=')) { const port = Number(a.split('=')[1]); if (Number.isInteger(port) && port > 0 && port <= 65535) return port; return null; } } return undefined; } async function main(argv) { const cmd = argv[0] || 'help'; if (cmd === 'help') { printHelp(); return; } if (cmd === 'start') { const portOpt = parsePortOption(argv.slice(1)); const port = portOpt === undefined ? 3000 : portOpt; if (portOpt === null) { console.error('Invalid port specified.'); printHelp(); process.exit(2); } console.log(`Starting server on port ${port}...`); await server.start(port); // server.start will keep the process alive return; } if (cmd === 'factorial') { const nRaw = argv[1]; if (!nRaw) { console.error('Please supply a number. Example: factorial 10'); process.exit(2); } const n = Number(nRaw); if (!Number.isInteger(n) || n < 0) { console.error('n must be a non-negative integer.'); process.exit(2); } try { const result = math.factorialBigInt(n); console.log(result.toString()); return; } catch (err) { console.error('Error computing factorial:', err && err.message ? err.message : err); process.exit(1); } } if (cmd === 'compute') { const payloadRaw = argv[1]; if (!payloadRaw) { console.error('Please supply JSON payload. Example: compute \'{"op":"add","args":[1,2]}\''); process.exit(2); } let payload; try { payload = JSON.parse(payloadRaw); } catch (err) { console.error('Invalid JSON payload:', err.message || err); process.exit(2); } try { const result = math.compute(payload); // Convert BigInt to string for printing if (typeof result === 'bigint') { console.log(result.toString()); } else { console.log(JSON.stringify({ result })); } return; } catch (err) { console.error('Computation error:', err && err.message ? err.message : err); process.exit(1); } } console.error('Unknown command:', cmd); printHelp(); process.exit(2); } module.exports = { main }; // Minimal HTTP server implementing a small JSON API without external deps. // Endpoints: // GET /ping -> { pong: true, timestamp } // GET /status -> { status: 'ok', uptime, memory } // GET /factorial?n= -> { n, factorial: "" } // POST /compute -> { result } accepts JSON { op, args } // Server supports graceful shutdown via stop(). const http = require('http'); const url = require('url'); const { factorialBigInt, compute } = require('./math'); let serverInstance = null; function sendJSON(res, statusCode, payload) { const body = JSON.stringify(payload); res.writeHead(statusCode, { 'Content-Type': 'application/json; charset=utf-8', 'Content-Length': Buffer.byteLength(body), 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Methods': 'GET,POST,OPTIONS', 'Access-Control-Allow-Headers': 'Content-Type' }); res.end(body); } function readJSONBody(req) { return new Promise((resolve, reject) => { let raw = ''; req.on('data', chunk => { raw += chunk; // Limit body size to 1MB if (raw.length > 1e6) { req.destroy(); reject(new Error('Payload too large')); } }); req.on('end', () => { if (!raw) return resolve(null); try { const parsed = JSON.parse(raw); resolve(parsed); } catch (err) { reject(new Error('Invalid JSON body')); } }); req.on('error', err => reject(err)); }); } async function requestHandler(req, res) { try { const parsed = url.parse(req.url, true); const pathname = parsed.pathname; if (req.method === 'OPTIONS') { // Preflight CORS response res.writeHead(204, { 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Methods': 'GET,POST,OPTIONS', 'Access-Control-Allow-Headers': 'Content-Type' }); return res.end(); } if (req.method === 'GET' && pathname === '/ping') { return sendJSON(res, 200, { pong: true, timestamp: new Date().toISOString() }); } if (req.method === 'GET' && pathname === '/status') { const mem = process.memoryUsage(); return sendJSON(res, 200, { status: 'ok', uptime: process.uptime(), memory: { rss: mem.rss, heapTotal: mem.heapTotal, heapUsed: mem.heapUsed } }); } if (req.method === 'GET' && pathname === '/factorial') { const nRaw = parsed.query.n; if (typeof nRaw === 'undefined') { return sendJSON(res, 400, { error: 'Missing query parameter n' }); } const n = Number(nRaw); if (!Number.isInteger(n) || n < 0) { return sendJSON(res, 400, { error: 'n must be a non-negative integer' }); } if (n > 5000) { return sendJSON(res, 400, { error: 'n too large (limit 5000 for safety)' }); } const result = factorialBigInt(n); return sendJSON(res, 200, { n, factorial: result.toString() }); } if (req.method === 'POST' && pathname === '/compute') { let payload; try { payload = await readJSONBody(req); } catch (err) { return sendJSON(res, 400, { error: 'Invalid JSON body' }); } if (!payload || typeof payload !== 'object') { return sendJSON(res, 400, { error: 'JSON body required' }); } try { const result = compute(payload); // Return BigInt as string if (typeof result === 'bigint') { return sendJSON(res, 200, { result: result.toString() }); } return sendJSON(res, 200, { result }); } catch (err) { return sendJSON(res, 400, { error: err.message || 'Computation error' }); } } // Not found sendJSON(res, 404, { error: 'Not found' }); } catch (err) { sendJSON(res, 500, { error: 'Internal server error', details: err && err.message ? err.message : String(err) }); } } function start(port = 3000) { return new Promise((resolve, reject) => { if (serverInstance) { return reject(new Error('Server already running')); } serverInstance = http.createServer(requestHandler); serverInstance.listen(port, () => { console.log(`API server listening on port ${port}`); resolve(); }); serverInstance.on('error', err => { console.error('Server error:', err); }); }); } function stop() { return new Promise((resolve, reject) => { if (!serverInstance) return resolve(); serverInstance.close(err => { serverInstance = null; if (err) return reject(err); resolve(); }); }); } module.exports = { start, stop }; // Math and compute utilities // factorialBigInt(n) -> BigInt // compute({op, args}) -> number | BigInt // Supported ops: add, mul, pow, factorial (accepts single integer arg) function factorialBigInt(n) { if (!Number.isInteger(n) || n < 0) { throw new Error('n must be a non-negative integer'); } // Safety guard if (n > 10000) throw new Error('n too large'); let res = 1n; for (let i = 2n; i <= BigInt(n); i++) { res *= i; } return res; } function sum(args) { return args.reduce((acc, x) => acc + Number(x), 0); } function mul(args) { return args.reduce((acc, x) => acc * Number(x), 1); } function pow(base, exponent) { // Use BigInt when both are integers and exponent non-negative integer const isIntegerBase = Number.isInteger(base); const isIntegerExp = Number.isInteger(exponent) && exponent >= 0; if (isIntegerBase && isIntegerExp) { return BigInt(base) ** BigInt(exponent); } return Math.pow(Number(base), Number(exponent)); } function compute(payload) { if (!payload || typeof payload !== 'object') throw new Error('Payload must be an object'); const op = payload.op; const args = payload.args; if (!op) throw new Error('Missing op'); if (!Array.isArray(args) && op !== 'factorial') throw new Error('args must be an array'); switch (op) { case 'add': case 'sum': return sum(args); case 'mul': case 'product': return mul(args); case 'pow': if (!Array.isArray(args) || args.length < 2) throw new Error('pow requires [base, exponent]'); return pow(args[0], args[1]); case 'factorial': // Accept single argument n in args or payload.n const n = Array.isArray(args) && args.length > 0 ? Number(args[0]) : Number(payload.n); if (!Number.isInteger(n) || n < 0) throw new Error('n must be a non-negative integer for factorial'); return factorialBigInt(n); default: throw new Error('Unsupported op: ' + op); } } module.exports = { factorialBigInt, compute }; Node executable with HTTP API Quick start: 1) Start the HTTP API server on default port (3000): node ./bin/cli.js start Or specify a port: node ./bin/cli.js start --port 4000 Available HTTP endpoints: GET /ping -> { pong: true, timestamp } GET /status -> { status, uptime, memory } GET /factorial?n=10 -> { n: 10, factorial: "3628800" } POST /compute -> Accepts JSON body like {"op":"add","args":[1,2,3]} 2) Run CLI commands without starting the server: Compute factorial locally: node ./bin/cli.js factorial 20 Compute an operation locally: node ./bin/cli.js compute '{"op":"mul","args":[2,3,4]}' Notes: - This project uses pure Node.js core modules (no external dependencies). - Factorial uses BigInt and returns results as strings in JSON responses.