The debounce-promise npm package is used to debounce promises, ensuring that a function is not called too frequently. This is particularly useful in scenarios where you want to limit the rate at which a function is executed, such as in search input fields or API calls.

What are debounce-promise's main functionalities?

Basic Debouncing

This feature allows you to debounce a function that returns a promise. In this example, the fetchData function is debounced with a delay of 300 milliseconds. This means that if fetchData is called multiple times within 300 milliseconds, it will only execute once.

const debounce = require('debounce-promise');
const fetchData = () => fetch('https://api.example.com/data');
const debouncedFetchData = debounce(fetchData, 300);

debouncedFetchData().then(response => response.json()).then(data => console.log(data));

Leading Edge Execution

This feature allows the debounced function to be executed immediately on the leading edge of the timeout, rather than waiting for the delay to pass. In this example, fetchData is executed immediately the first time it is called, and then debounced for subsequent calls.

const debounce = require('debounce-promise');
const fetchData = () => fetch('https://api.example.com/data');
const debouncedFetchData = debounce(fetchData, 300, { leading: true });

debouncedFetchData().then(response => response.json()).then(data => console.log(data));

Trailing Edge Execution

This feature ensures that the debounced function is executed at the trailing edge of the timeout. In this example, fetchData will be executed after the 300 milliseconds delay if no new calls are made within that period.

const debounce = require('debounce-promise');
const fetchData = () => fetch('https://api.example.com/data');
const debouncedFetchData = debounce(fetchData, 300, { trailing: true });

debouncedFetchData().then(response => response.json()).then(data => console.log(data));

Other packages similar to debounce-promise

Readme

Source

debounce-promise

Create a debounced version of a promise returning function

Usage example


var debounce = require('debounce-promise')

function expensiveOperation(value) {
  return Promise.resolve(value)
}

var saveCycles = debounce(expensiveOperation, 100)

;[1,2,3,4].forEach(function(num) {
  return saveCycles('call no #' + num).then(function(value) {
    console.log(value)
  })
})

// Will only call expensiveOperation once with argument `4` and print:
//=> call no #4
//=> call no #4
//=> call no #4
//=> call no #4

With leading=true

var debounce = require('debounce-promise')

function expensiveOperation(value) {
  return Promise.resolve(value)
}

var saveCycles = debounce(expensiveOperation, 100, {leading: true})

;[1,2,3,4].forEach(function(num) {
  return saveCycles('call no #' + num).then(function(value) {
    console.log(value)
  })
})

//=> call no #1
//=> call no #1
//=> call no #1
//=> call no #1

Api

debounce(func, [wait=0], [{leading: true|false})

Returns a debounced version of func that delays invoking until after wait milliseconds. Set leading: true if you want to call func immediately and use the value from the first call for all subsequent promises

FAQs

What is debounce-promise?

Is debounce-promise well maintained?

Last updated on 18 Oct 2015

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