newstex / debounce-promise

Create a debounced version of a promise returning function

debounce-promise

Create a debounced version of a promise returning function

Install

npm i -S debounce-promise

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.

Supports passing a function as the wait parameter, which provides a way to lazily or dynamically define a wait timeout.