90 lines
4.2 KiB
Markdown
90 lines
4.2 KiB
Markdown
---
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id: 5a24c314108439a4d4036177
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title: Write a Simple Counter
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challengeType: 6
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isRequired: false
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videoUrl: ''
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localeTitle: ''
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---
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## Description
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undefined
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## Instructions
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undefined
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: ''
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testString: 'assert((() => { const mockedComponent = Enzyme.mount(React.createElement(Counter)); return (mockedComponent.find(".inc").text() === "Increment!" && mockedComponent.find(".dec").text() === "Decrement!" && mockedComponent.find(".reset").text() === "Reset"); })(), "<code>Counter</code> should return a <code>div</code> element which contains three buttons with text content in this order <code>Increment!</code>, <code>Decrement!</code>, <code>Reset</code>.");'
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- text: ''
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testString: 'assert.strictEqual(Enzyme.mount(React.createElement(Counter)).state("count"), 0, "The state of <code>Counter</code> should initialize with a <code>count</code> property set to <code>0</code>.");'
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- text: ''
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testString: 'async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 250)); const mockedComponent = Enzyme.mount(React.createElement(Counter)); const first = () => { mockedComponent.setState({ count: 0 }); return waitForIt(() => mockedComponent.state("count")); }; const second = () => { mockedComponent.find(".inc").simulate("click"); return waitForIt(() => mockedComponent.state("count")); }; const firstValue = await first(); const secondValue = await second(); assert(firstValue === 0 && secondValue === 1, "Clicking the increment button should increment the count by <code>1</code>."); }; '
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- text: ''
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testString: 'async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 250)); const mockedComponent = Enzyme.mount(React.createElement(Counter)); const first = () => { mockedComponent.setState({ count: 0 }); return waitForIt(() => mockedComponent.state("count")); }; const second = () => { mockedComponent.find(".dec").simulate("click"); return waitForIt(() => mockedComponent.state("count")); }; const firstValue = await first(); const secondValue = await second(); assert(firstValue === 0 && secondValue === -1, "Clicking the decrement button should decrement the count by <code>1</code>."); }; '
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- text: ''
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testString: 'async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 250)); const mockedComponent = Enzyme.mount(React.createElement(Counter)); const init = () => { mockedComponent.setState({ count: 0 }); return waitForIt(() => mockedComponent.state("count")); }; const increment = () => { mockedComponent.find(".inc").simulate("click"); mockedComponent.find(".inc").simulate("click"); return waitForIt(() => mockedComponent.state("count")); }; const decrement = () => { mockedComponent.find(".dec").simulate("click"); return waitForIt(() => mockedComponent.state("count")); }; const reset = () => { mockedComponent.find(".reset").simulate("click"); return waitForIt(() => mockedComponent.state("count")); }; const firstValue = await init(); const secondValue = await increment(); const thirdValue = await decrement(); const fourthValue = await reset(); assert(firstValue === 0 && secondValue === 2 && thirdValue === 1 && fourthValue === 0, "Clicking the reset button should reset the count to <code>0</code>."); }; '
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='jsx-seed'>
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```jsx
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class Counter extends React.Component {
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constructor(props) {
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super(props);
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this.state = {
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count: 0
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};
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// change code below this line
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// change code above this line
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}
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// change code below this line
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// change code above this line
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render() {
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return (
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<div>
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<button className='inc' onClick={this.increment}>Increment!</button>
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<button className='dec' onClick={this.decrement}>Decrement!</button>
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<button className='reset' onClick={this.reset}>Reset</button>
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<h1>Current Count: {this.state.count}</h1>
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</div>
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);
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}
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};
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```
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</div>
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### After Test
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<div id='jsx-teardown'>
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```js
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console.info('after the test');
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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