Actually, you don’t need to use Sinon to test debounces. Jest can mock all timers in JavaScript code. Check out following code (it’s TypeScript, but you can easily translate it to JavaScript): import * as _ from ‘lodash’; // Tell Jest to mock all timeout functions jest.useFakeTimers(); describe(‘debounce’, () => { let func: jest.Mock; let … Read more
I ran into the same issue. The problem is happening because the debounce function returns a new function which isn’t being called anywhere. To fix this, you will have to pass in the debouncing function as a parameter to the jquery click event. Here is the code that you should have. $(“.my-btn”).click($.debounce(250, function(e) { console.log(“It … Read more
Every time your component re-renders, a new debounced verify function is created, which means that inside useEffect you are actually calling different functions which defeats the purpose of debouncing. It’s like you were doing something like this: const debounced1 = debounce(() => { console.log(state.username) }, 1000); debounced1(); const debounced2 = debounce(() => { console.log(state.username) }, … Read more
The problem occurs because you aren’t calling the debounce function, you could do in the following manner export default class componentName extends Component { constructor(props) { super(props); this.state = { value: this.props.value || null } this.servicesValue = _.debounce(this.servicesValue, 1000); } onChange(value) { this.setState({ value }); this.servicesValue(value); } servicesValue = (value) => { Services.setValue(value) } render() … Read more
With a functional react component try using useCallback. useCallback memoizes your debounce function so it doesn’t get recreated again and again when the component rerenders. Without useCallback the debounce function will not sync with the next key stroke. ` import {useCallback} from ‘react’; import _debounce from ‘lodash/debounce’; import axios from ‘axios’; function Input() { const … Read more
debounceLoadData will be a new function for every render. You can use the useCallback hook to make sure that the same function is being persisted between renders and it will work as expected. useCallback(debounce(loadData, 1000), []); const { useState, useCallback } = React; const { debounce } = _; function App() { const [filter, setFilter] … Read more
I’ve used this to debounce events with some success: public static Action<T> Debounce<T>(this Action<T> func, int milliseconds = 300) { var last = 0; return arg => { var current = Interlocked.Increment(ref last); Task.Delay(milliseconds).ContinueWith(task => { if (current == last) func(arg); task.Dispose(); }); }; } Usage Action<int> a = (arg) => { // This was … Read more
Works on Android, iOS, Web, macOS, Windows and Linux You can implement a custom TextInputFormatter class UpperCaseTextFormatter extends TextInputFormatter { @override TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) { return TextEditingValue( text: newValue.text.toUpperCase(), selection: newValue.selection, ); } } Usage: TextField( inputFormatters: [ UpperCaseTextFormatter(), ] ) Full example
You’ll have to use a setTimeout (like you are) but also store the reference so you can keep resetting the limit. Something like: // // $(‘#element’).donetyping(callback[, timeout=1000]) // Fires callback when a user has finished typing. This is determined by the time elapsed // since the last keystroke and timeout parameter or the blur event–whichever … Read more
Angular 4+, Using Observable.timer(debounceTime) : @izupet ‘s answer is right but it is worth noticing that it is even simpler when you use Observable: emailAvailability(control: Control) { return Observable.timer(500).switchMap(()=>{ return this._service.checkEmail({email: control.value}) .mapTo(null) .catch(err=>Observable.of({availability: true})); }); } Since angular 4 has been released, if a new value is sent for checking, Angular unsubscribes from Observable … Read more