2.1 KiB
2.1 KiB
id | title | challengeType | isRequired | videoUrl | localeTitle |
---|---|---|---|---|---|
5a24c314108439a4d403617d | Use the Lifecycle Method componentDidMount | 6 | false |
Description
undefined
Instructions
undefined
Tests
tests:
- text: ''
testString: 'assert((() => { const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); return (mockedComponent.find("div").length === 1 && mockedComponent.find("h1").length === 1); })(), "<code>MyComponent</code> should render a <code>div</code> element which wraps an <code>h1</code> tag.");'
- text: ''
testString: 'assert((() => { const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); return new RegExp("setTimeout(.|\n)+setState(.|\n)+activeUsers").test(String(mockedComponent.instance().componentDidMount)); })(), "Component state should be updated with a timeout function in <code>componentDidMount</code>.");'
- text: ''
testString: 'async () => { const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); const first = () => { mockedComponent.setState({ activeUsers: 1237 }); return mockedComponent.find("h1").text(); }; const second = () => { mockedComponent.setState({ activeUsers: 1000 }); return mockedComponent.find("h1").text(); }; assert(new RegExp("1237").test(first()) && new RegExp("1000").test(second()), "The <code>h1</code> tag should render the <code>activeUsers</code> value from <code>MyComponent</code>'s state."); }; '
Challenge Seed
class MyComponent extends React.Component {
constructor(props) {
super(props);
this.state = {
activeUsers: null
};
}
componentDidMount() {
setTimeout( () => {
this.setState({
activeUsers: 1273
});
}, 2500);
}
render() {
return (
<div>
<h1>Active Users: { /* change code here */ }</h1>
</div>
);
}
};
After Test
console.info('after the test');
Solution
// solution required