Node.js Reliable Programming

The Problem

Crashes and subtle failures in Node.js projects often come from async boundaries, module caching, stream backpressure, environment typing, and dependency structure rather than syntax alone. fs.readFileSync can block the event loop, unhandled rejections may terminate Node 15+ processes, process.env values are always strings, and require() caching plus circular dependencies can make shared object state hard to reason about.

How It Works

The skill organizes quick references by topic: async.md covers callbacks, Promises, async/await, and the event loop; modules.md compares CommonJS and ESM; errors.md addresses uncaught exceptions; streams.md focuses on Readable, Writable, Transform, and backpressure; performance.md covers memory leaks, event loop blocking, and profiling; security.md covers input validation, dependencies, and environment variables; testing.md covers Jest/Mocha, mocking, and integration tests; packages.md covers npm, package.json, lockfiles, and publishing. The core is engineering guardrails around common traps: prefer fs.promises.readFile, wrap JSON.parse in try/catch, use pipeline() instead of .pipe(), and use fileURLToPath(import.meta.url) in ESM.

Boundaries

It is best for triage, review, and refactoring of existing Node.js services or libraries. The skill does not provide business architecture decisions, nor does it replace a full test environment. For ESM/CJS hybrids, multi-process setups, or containerized networking, decisions should be made with project dependencies and runtime versions in mind.