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How to use useCounter method in testing-library-react-hooks
Best JavaScript code snippet using testing-library-react-hooks
index.test.ts
Source:index.test.ts 
...4 describe("without observer", () => {5 test("value update across components", () => {6 const [useCounter, setCounter] = createGalactic(0);7 const { result: result1, rerender: rerender1 } = renderHook(() =>8 useCounter()9 );10 const { result: result2, rerender: rerender2 } = renderHook(() =>11 useCounter()12 );13 act(() => {14 setCounter(1);15 });16 rerender1();17 rerender2();18 expect(result1.current[0]).toBe(1);19 expect(result2.current[0]).toBe(1);20 });21 test("update value with callback", () => {22 const [useCounter, setCounter] = createGalactic(0);23 const { result: result1, rerender: rerender1 } = renderHook(() =>24 useCounter()25 );26 const { result: result2, rerender: rerender2 } = renderHook(() =>27 useCounter()28 );29 act(() => {30 setCounter((current) => current + 1);31 });32 rerender1();33 rerender2();34 expect(result1.current[0]).toBe(1);35 expect(result2.current[0]).toBe(1);36 });37 });38 describe("with observer", () => {39 test("observer receives state updates", () => {40 const [useCounter, setCounter, counterObserver] = createGalactic(0);41 const { result: result1, rerender: rerender1 } = renderHook(() =>42 useCounter()43 );44 const { result: result2, rerender: rerender2 } = renderHook(() =>45 useCounter()46 );47 const counterSub = jest.fn();48 counterObserver.subscribe(counterSub);49 act(() => {50 setCounter(1);51 });52 rerender1();53 rerender2();54 expect(result1.current[0]).toBe(1);55 expect(result2.current[0]).toBe(1);56 expect(counterSub).toHaveBeenCalledWith(1);57 act(() => {58 setCounter(55);59 });60 rerender1();61 expect(result1.current[0]).toBe(55);62 expect(counterSub).toHaveBeenCalledWith(55);63 });64 test("observer updates component states", () => {65 const [useCounter, setCounter] = createGalactic(0);66 const { result: result1, rerender: rerender1 } = renderHook(() =>67 useCounter()68 );69 const { result: result2, rerender: rerender2 } = renderHook(() =>70 useCounter()71 );72 act(() => {73 setCounter(55);74 });75 rerender1();76 rerender2();77 expect(result1.current[0]).toBe(55);78 expect(result2.current[0]).toBe(55);79 });80 test("observer updates component states using callback", () => {81 const [useCounter, setCounter] = createGalactic(0);82 const { result: result1, rerender: rerender1 } = renderHook(() =>83 useCounter()84 );85 const { result: result2, rerender: rerender2 } = renderHook(() =>86 useCounter()87 );88 act(() => {89 setCounter((currentVal) => currentVal + 55);90 });91 rerender1();92 rerender2();93 expect(result1.current[0]).toBe(55);94 expect(result2.current[0]).toBe(55);95 });96 });...
simple.test.js
Source:simple.test.js
...12});13afterEach(cleanup);14test('should return initial counter value', () => {15 let count;16 renderHook(() => ([count] = useCounter()));17 expect(count).toBe(0);18});19test('should increase/decrease counter value', () => {20 let count, setCount;21 renderHook(() => ([count, setCount] = useCounter()));22 expect(count).toBe(0);23 act(() => {24 setCount(1);25 });26 expect(count).toBe(1);27});28test('should increase/decrease counter value from standalone', () => {29 let count;30 renderHook(() => ([count] = useCounter()));31 expect(count).toBe(0);32 const [, setCount] = useCounter.get();33 act(() => {34 setCount(1);35 });36 expect(count).toBe(1);37});38test('should shared hook output', () => {39 let out1;40 renderHook(() => (out1 = useCounter()));41 let out2;42 renderHook(() => (out2 = useCounter()));43 expect(out1).toBe(out2);44 let [count] = out2;45 expect(count).toBe(0);46 const [, setCount] = out1;47 act(() => {48 setCount(2);49 });50 [count] = out2;51 expect(count).toBe(2);52 expect(out1).toBe(out2);53});54test('should shared hook output#2', () => {55 let out1;56 renderHook(() => (out1 = useCounter2()));57 let out2;58 renderHook(() => (out2 = useCounter2()));59 expect(out1).toBe(out2);60 let { count } = out2;61 expect(count).toBe(0);62 const { setCount } = out1;63 act(() => {64 setCount(2);65 });66 count = out2.count;67 expect(count).toBe(2);68 expect(out1).toBe(out2);69});70test('should ignore initial param from hook call', () => {71 let count1;72 renderHook(() => ([count1] = useCounter(1)));73 let count2;74 renderHook(() => ([count2] = useCounter(2))); // ignore non-host initial75 expect(count1).toBe(0);76 expect(count1).toBe(count2);77});78test('should non-Host continue life after Host unmount', () => {79 const { unmount } = renderHook(() => useCounter()); // render Hookleton Host80 let count;81 renderHook(() => ([count] = useCounter())); // a non-Host82 expect(count).toBe(0);83 unmount(); // Host84 // 'non-Host' still have state but setCount cannot be called, a new Host is needed85 expect(count).toBe(0);...
index.js
Source:index.js
1var App = require('lfa-core').App;2var Storage = require('lfa-core').Storage;3var $ = require('jquery');4App.book.on('render', function() {5 if(window.location.href.substr(-12) == 'ch99-contact')6 {7 $('#textbook').css('padding','0');8 $('section').css('padding','0');9 }10 if($('li.active').parent(0).is('li'))11 {12 console.log('yes');13 $('li.active').parent(0).addClass('activeParent');14 }15 else16 {17 console.log('yesy' + $('li.active').parent());18 $('li.active').addClass('activeParent');19 }20 $('#leftbar li:not(.active)').removeClass('activeParent');21});22(function() {23 'use strict';24 var $ = require('bootstrap');25 window.firstTimeDoneMessages = [26 'Bravo!',27 'Congrats!',28 'Excellent!',29 'Correct!',30 'Super!',31 'Impressive!',32 'Flawless!'33 ];34 var greetings = ['Welcome!', 'Hi!', 'Good day!', 'Howdy!', 'What\'s up?'];35 var hh = (new Date()).getHours();36 if (hh >= 2 && hh < 12) {37 greetings.push('Good morning!');38 } else if (hh > 17 || hh < 2) {39 greetings.push('Good evening!!');40 } else {41 greetings.push('Hello!');42 }43 var useCounter = Storage.getItem('useCounter') || 0;44 useCounter = parseInt(useCounter) + 1;45 Storage.setItem('useCounter', useCounter);46 var message = greetings[Math.min(Math.floor(Math.random() *47 greetings.length * 1.5), greetings.length - 1)];48 if (useCounter < 2) {49 message = 'Thank you for trying this!';50 }51 setTimeout(function() {52 App.trigger('avatar:mood', {53 mood: 'smile',54 message: message,55 interval: 5000,56 icon: 'fa-smile-o'57 });58 }, 4000);59 App.book.on('render', function( /*opts*/ ) {60 var classroom = require('lfa-classroom');61 var ClassmateList = classroom.ClassmateList;62 var NameInput = classroom.NameInput;63 console.log(classroom, ClassmateList, NameInput);64 var studentList = document.getElementById('student-list');65 if (studentList) {66 React.render(67 React.createElement(ClassmateList, null),68 studentList69 );70 }71 var nameInput = document.getElementById('cover-name-input');72 if (nameInput) {73 React.render(74 React.createElement(NameInput, null),75 nameInput76 );77 }78 });79 $('body').after('<script type="text/javascript" src="https://news.lfwd.io/banner.js"></script>');...
useCounter.test.js
Source:useCounter.test.js
1import { renderHook } from "@testing-library/react-hooks"2import { useCounter } from "./useCounter"3describe("useCounter", () => {4 it("should call useCounter", () => {5 const { result } = renderHook(() => useCounter())6 expect(result.current.count).toBe(0)7 expect(typeof result.current.increment).toBe("function")8 })9 it("should call increment", () => {10 const { result } = renderHook(() => useCounter())11 result.current.increment()12 expect(result.current.count).toBe(1)13 })14 it("should call increment with initial value", () => {15 const { result } = renderHook(() => useCounter(10))16 result.current.increment()17 expect(result.current.count).toBe(11)18 })19 it("should call reset", () => {20 const { result, rerender } = renderHook(21 ({ initialValue }) => useCounter(initialValue),22 {23 initialValue: 0,24 },25 )26 rerender({ initialValue: 10 })27 result.current.reset()28 expect(result.current.count).toBe(10)29 })30 it("should call incrementAsync", async () => {31 const { result, waitForNextUpdate } = renderHook(() => useCounter(0))32 result.current.incrementAsync()33 await waitForNextUpdate()34 expect(result.current.count).toBe(1)35 })...
useCounter-test.js
Source:useCounter-test.js
2import { useCounter } from "./useCounter"34describe("useCounter", () => {5 it("useCounter", () => {6 const { result } = renderHook(() => useCounter())78 expect(result.current.count).toBe(0)9 expect(typeof result.current.count).toBe("function")10 })1112 it("useCounter increment", () => {13 const { result } = renderHook(() => useCounter())1415 expect(result.current.count).toBe(1)16 })1718 it("useCounter increment with initial value", () => {19 const { result } = renderHook(() => useCounter(10))2021 expect(result.current.count).toBe(11)22 })2324 it("test reset", () => {25 const { result, rerender } = renderHook(26 ({ initialValue }) => useCounter(initialValue),27 {28 initialValue: 0,29 },30 )3132 rerender({ initialValue: 10 })3334 expect(result.current.count).toBe(10)35 })3637 it("test incrementAsync", async () => {38 const { result, waitForNextUpdate } = renderHook(() => useCounter(0))3940 result.current.incrementAsync()4142 await waitForNextUpdate()4344 expect(result.current.count).toBe(1)45 })
...
Using AI Code Generation
1import { renderHook, act } from '@testing-library/react-hooks'2import useCounter from './useCounter'3test('should increment counter', () => {4 const { result } = renderHook(() => useCounter())5 act(() => {6 result.current.increment()7 })8 expect(result.current.count).toBe(1)9})10export default function useCounter() {11 const [count, setCount] = React.useState(0)12 const increment = () => setCount((c) => c + 1)13 return {14 }15}
Using AI Code Generation
1import { renderHook, act } from '@testing-library/react-hooks';2import useCounter from './useCounter';3test('should increment counter', () => {4 const { result } = renderHook(() => useCounter());5 act(() => {6 result.current.increment();7 });8 expect(result.current.count).toBe(1);9});10import { useState } from 'react';11const useCounter = () => {12 const [count, setCount] = useState(0);13 const increment = () => setCount(count + 1);14 return { count, increment };15};16export default useCounter;17import { renderHook, act } from '@testing-library/react-hooks';18import useCounter from './useCounter';19test('should increment counter', () => {20 const { result } = renderHook(() => useCounter());21 act(() => {22 result.current.increment();23 });24 expect(result.current.count).toBe(1);25});26import { useState } from 'react';27const useCounter = () => {28 const [count, setCount] = useState(0);29 const increment = () => setCount(count + 1);30 return { count, increment };31};32export default useCounter;33import { renderHook, act } from '@testing-library/react-hooks';34import useCounter from './useCounter';35test('should increment counter', () => {36 const { result } = renderHook(() => useCounter());37 act(() => {38 result.current.increment();39 });40 expect(result.current.count).toBe(1);41});42import { useState } from 'react';43const useCounter = () => {44 const [count, setCount] = useState(0);45 const increment = () => setCount(count + 1);46 return { count, increment };47};48export default useCounter;49import { renderHook, act } from '@testing-library/react-hooks';50import useCounter from './useCounter';51test('should increment counter', () => {52 const { result } = renderHook(() => useCounter());53 act(() => {54 result.current.increment();
Using AI Code Generation
1import { renderHook, act } from '@testing-library/react-hooks'2import useCounter from './useCounter'3test('should increment counter', () => {4 const { result } = renderHook(() => useCounter())5 act(() => {6 result.current.increment()7 })8 expect(result.current.count).toBe(1)9})10test('should decrement counter', () => {11 const { result } = renderHook(() => useCounter())12 act(() => {13 result.current.decrement()14 })15 expect(result.current.count).toBe(-1)16})17test('should reset counter', () => {18 const { result } = renderHook(() => useCounter())19 act(() => {20 result.current.increment()21 result.current.reset()22 })23 expect(result.current.count).toBe(0)24})25import { useState } from 'react'26const useCounter = () => {27 const [count, setCount] = useState(0)28 const increment = () => {29 setCount(count + 1)30 }31 const decrement = () => {32 setCount(count - 1)33 }34 const reset = () => {35 setCount(0)36 }37 return { count, increment, decrement, reset }38}
Using AI Code Generation
1import { renderHook, act } from '@testing-library/react-hooks'2import useCounter from './useCounter'3describe('useCounter', () => {4 it('should increment counter', () => {5 const { result } = renderHook(() => useCounter())6 act(() => {7 result.current.increment()8 })9 expect(result.current.count).toBe(1)10 })11})12import { useState } from 'react'13const useCounter = () => {14 const [count, setCount] = useState(0)15 const increment = () => {16 setCount(count + 1)17 }18 return {19 }20}
Using AI Code Generation
1import {useCounter} from './counter';2import {renderHook} from '@testing-library/react-hooks';3describe('useCounter', () => {4 it('should use the counter', () => {5 const {result} = renderHook(() => useCounter());6 expect(result.current.count).toBe(0);7 act(() => {8 result.current.increment();9 });10 expect(result.current.count).toBe(1);11 });12});13import {useState} from 'react';14export const useCounter = () => {15 const [count, setCount] = useState(0);16 const increment = () => setCount((count) => count + 1);17 return {count, increment};18};19import React from 'react';20import {useCounter} from './counter';21const App = () => {22 const {count, increment} = useCounter();23 return (24 <h1>{count}</h1>25 <button onClick={increment}>Increment</button>26 );27};28export default App;
Using AI Code Generation
1export const useCounter = () => {2 const [count, setCount] = useState(0);3 const increment = () => setCount(count + 1);4 return { count, increment };5};6import { useCounter } from './useCounter';7import { useCounter } from './useCounter';
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