debounce

Debounce: when a function is triggered rapidly, run it only after the triggering stops for ms milliseconds. Use it when only the final state matters — search-as-you-type, window resize, autosave.

For "I need the intermediate values too", use throttle.

API

debounce(fn, ms?)

Parameters

Parameter	Description	Type	Default
fn	Function to debounce	Function	Required
ms	Quiet period (ms)	number	500

Return

A debounced function that keeps the call-site this and the last arguments, plus:

Member	Description	Type
cancel()	Drop the pending call	() => void
flush()	Run the pending call right now (e.g. before submitting)	() => void
pending()	Whether a call is waiting	() => boolean

Example

import { debounce } from 'ranuts';

const save = debounce((draft) => api.save(draft), 800);
input.addEventListener('input', (e) => save(e.target.value));

form.addEventListener('submit', () => save.flush()); // don't lose the last keystroke
onUnmount(() => save.cancel());

Notes

1. Only the last call runs, with the arguments of that last call.
2. this is taken from the call site — obj.handler() sees obj.
3. Always cancel() on teardown, otherwise the pending timer fires into a destroyed context.
4. Fully typed: parameter and return types are inferred from fn.