node
When to use
Use this skill whenever you are dealing with Node.js code to obtain domain-specific knowledge for building robust, performant, and maintainable Node.js applications.
Common Workflows
For multi-step processes, follow these high-level sequences before consulting the relevant rule file:
Graceful shutdown: Register signal handlers (SIGTERM/SIGINT) → stop accepting new work → drain in-flight requests → close external connections (DB, cache) → exit with appropriate code. See rules/graceful-shutdown.md.
Error handling: Define a shared error base class → classify errors (operational vs programmer) → add async boundary handlers (process.on('unhandledRejection')) → propagate typed errors through the call stack → log with context before responding or crashing. See rules/error-handling.md.
Diagnosing flaky tests: Isolate the test with --test-only → check for shared state or timer dependencies → inspect async teardown order → add retry logic as a temporary diagnostic step → fix root cause. See rules/flaky-tests.md.
Diagnosing stuck processes/tests (node --test hangs, "process did not exit", CI timeout, open handles): isolate file/test → run with explicit timeout/reporter → inspect handles via why-is-node-running (SIGUSR1) → patch deterministic teardown in resource-creation scope → rerun isolated + full suite until stable. See rules/stuck-processes-and-tests.md.
Profiling a slow path: Reproduce under realistic load → capture a CPU profile with --cpu-prof → identify hot functions → check for stream backpressure or unnecessary serialisation → validate improvement with a benchmark. See rules/profiling.md and rules/performance.md.