tilfluktsrom/pwa/node_modules/why-is-node-running/README.md
Ole-Morten Duesund e8428de775 Add progressive web app companion for cross-platform access
Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-08 17:41:38 +01:00

2.5 KiB

why-is-node-running

Node is running but you don't know why? why-is-node-running is here to help you.

Installation

Node 8 and above:

npm i why-is-node-running -g

Earlier Node versions (no longer supported):

npm i why-is-node-running@v1.x -g

Usage

const log = require('why-is-node-running') // should be your first require
const net = require('net')

function createServer () {
  const server = net.createServer()
  setInterval(function () {}, 1000)
  server.listen(0)
}

createServer()
createServer()

setTimeout(function () {
  log() // logs out active handles that are keeping node running
}, 100)

Save the file as example.js, then execute:

node ./example.js

Here's the output:

There are 5 handle(s) keeping the process running

# Timeout
/home/maf/dev/node_modules/why-is-node-running/example.js:6  - setInterval(function () {}, 1000)
/home/maf/dev/node_modules/why-is-node-running/example.js:10 - createServer()

# TCPSERVERWRAP
/home/maf/dev/node_modules/why-is-node-running/example.js:7  - server.listen(0)
/home/maf/dev/node_modules/why-is-node-running/example.js:10 - createServer()

# Timeout
/home/maf/dev/node_modules/why-is-node-running/example.js:6  - setInterval(function () {}, 1000)
/home/maf/dev/node_modules/why-is-node-running/example.js:11 - createServer()

# TCPSERVERWRAP
/home/maf/dev/node_modules/why-is-node-running/example.js:7  - server.listen(0)
/home/maf/dev/node_modules/why-is-node-running/example.js:11 - createServer()

# Timeout
/home/maf/dev/node_modules/why-is-node-running/example.js:13 - setTimeout(function () {

Important Note! unrefed timers do not prevent the Node process from exiting. If you are running with Node v11.0.0 and above, unrefed timers will not be listed in the above list. Unfortunately, this is not supported in node versions below v11.0.0.

CLI

You can also run why-is-node-running as a standalone if you don't want to include it inside your code. Sending SIGUSR1/SIGINFO signal to the process will produce the log. (Ctrl + T on macOS and BSD systems)

why-is-node-running /path/to/some/file.js
probing module /path/to/some/file.js
kill -SIGUSR1 31115 for logging

To trigger the log:

kill -SIGUSR1 31115

Require CLI Option

You can also use the node -r option to include why-is-node-running:

node -r why-is-node-running/include /path/to/some/file.js

The steps are otherwise the same as the above CLI section

License

MIT