on-exit-leak-free

This module helps dispose of an object gracefully when the Node.js process exits. It executes a function with a given parameter on 'exit' without leaking memory, cleaning things up appropriately if the object is garbage collected.

Requires WeakRef and FinalizationRegistry, i.e. use Node v14+.

Install

1npm i on-exit-leak-free

Example

1'use strict'
2
3const { register, unregister } = require('on-exit-leak-free')
4const assert = require('assert')
5
6function setup () {
7  // This object can be safely garbage collected,
8  // and the resulting shutdown function will not be called.
9  // There are no leaks.
10  const obj = { foo: 'bar' }
11  register(obj, shutdown)
12  // use registerBeforeExit(obj, shutdown) to execute the function only
13  // on beforeExit
14  // call unregister(obj) to remove
15}
16
17let shutdownCalled = false
18
19// Please make sure that the function passed to register()
20// does not create a closure around unnecessary objects.
21function shutdown (obj, eventName) {
22  console.log(eventName) // beforeExit
23  shutdownCalled = true
24  assert.strictEqual(obj.foo, 'bar')
25}
26
27setup()
28
29process.on('exit', function () {
30  assert.strictEqual(shutdownCalled, true)
31})

License

MIT