* chore: rename APIs and Microservices to include "Backend" (#42515) * fix typo * fix typo * undo change * Corrected grammar mistake Corrected a grammar mistake by removing a comma. * change APIs and Microservices cert title * update title * Change APIs and Microservices certi title * Update translations.json * update title * feat(curriculum): rename apis and microservices cert * rename folder structure * rename certificate * rename learn Markdown * apis-and-microservices -> back-end-development-and-apis * update backend meta * update i18n langs and cypress test Co-authored-by: Shaun Hamilton <shauhami020@gmail.com> * fix: add development to front-end libraries (#42512) * fix: added-the-word-Development-to-front-end-libraries * fix/added-the-word-Development-to-front-end-libraries * fix/added-word-development-to-front-end-libraries-in-other-related-files * fix/added-the-word-Development-to-front-end-and-all-related-files * fix/removed-typos-from-last-commit-in-index.md * fix/reverted-changes-that-i-made-to-dependecies * fix/removed xvfg * fix/reverted changes that i made to package.json * remove unwanted changes * front-end-development-libraries changes * rename backend certSlug and README * update i18n folder names and keys * test: add legacy path redirect tests This uses serve.json from the client-config repo, since we currently use that in production * fix: create public dir before moving serve.json * fix: add missing script * refactor: collect redirect tests * test: convert to cy.location for stricter tests * rename certificate folder to 00-certificates * change crowdin config to recognise new certificates location * allow translations to be used Co-authored-by: Nicholas Carrigan (he/him) <nhcarrigan@gmail.com> * add forwards slashes to path redirects * fix cypress path tests again * plese cypress * fix: test different challenge Okay so I literally have no idea why this one particular challenge fails in Cypress Firefox ONLY. Tom and I paired and spun a full build instance and confirmed in Firefox the page loads and redirects as expected. Changing to another bootstrap challenge passes Cypress firefox locally. Absolutely boggled by this. AAAAAAAAAAAAAAA * fix: separate the test Okay apparently the test does not work unless we separate it into a different `it` statement. >:( >:( >:( >:( Co-authored-by: Sujal Gupta <55016909+heysujal@users.noreply.github.com> Co-authored-by: Noor Fakhry <65724923+NoorFakhry@users.noreply.github.com> Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com> Co-authored-by: Nicholas Carrigan (he/him) <nhcarrigan@gmail.com>
147 lines
4.2 KiB
Markdown
147 lines
4.2 KiB
Markdown
---
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id: 5a24c314108439a4d4036177
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title: Scrivere un semplice contatore
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challengeType: 6
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forumTopicId: 301425
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dashedName: write-a-simple-counter
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---
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# --description--
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È possibile progettare un componente stateful più complesso combinando i concetti visti finora. Questi includono l'inizializzazione dello `state`, la scrittura di metodi che impostano lo `state` e l'assegnazione di gestori di click per attivare questi metodi.
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# --instructions--
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Il componente `Counter` tiene traccia di un valore `count` nello `state`. Ci sono due bottoni che chiamano i metodi `increment()` e `decrement()`. Scrivi questi metodi in modo che il valore del contatore venga incrementato o decrementato di 1 quando viene fatto click sul bottone appropriato. Inoltre, crea un metodo `reset()` in modo che quando si clicca il pulsante reset, il conteggio venga impostato a 0.
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**Nota:** Assicurati di non modificare le `className` dei bottoni. Inoltre, ricordati di aggiungere i legami (bindings) necessari ai metodi appena creati nel costruttore.
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# --hints--
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`Counter` dovrebbe restituire un elemento `div` che contiene tre pulsanti con contenuto di testo nell'ordine: `Increment!`, `Decrement!`, `Reset`.
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```js
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assert(
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(() => {
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const mockedComponent = Enzyme.mount(React.createElement(Counter));
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return (
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mockedComponent.find('.inc').text() === 'Increment!' &&
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mockedComponent.find('.dec').text() === 'Decrement!' &&
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mockedComponent.find('.reset').text() === 'Reset'
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);
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})()
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);
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```
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Lo stato di `Counter` dovrebbe essere inizializzato con una proprietà `count` impostata a `0`.
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```js
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const mockedComponent = Enzyme.mount(React.createElement(Counter));
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assert(mockedComponent.find('h1').text() === 'Current Count: 0');
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```
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Cliccando sul bottone di incremento il conteggio dovrebbe aumentare di `1`.
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```js
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const mockedComponent = Enzyme.mount(React.createElement(Counter));
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mockedComponent.find('.inc').simulate('click');
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assert(mockedComponent.find('h1').text() === 'Current Count: 1');
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```
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Cliccando sul bottone di decremento il conteggio dovrebbe diminuire di `1`.
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```js
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const mockedComponent = Enzyme.mount(React.createElement(Counter));
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mockedComponent.find('.dec').simulate('click');
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assert(mockedComponent.find('h1').text() === 'Current Count: -1');
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```
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Cliccando sul bottone di reset il conteggio dovrebbe essere reimpostato a `0`.
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```js
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const mockedComponent = Enzyme.mount(React.createElement(Counter));
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mockedComponent.setState({ count: 5 });
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const currentCountElement = mockedComponent.find('h1');
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assert(currentCountElement.text() === 'Current Count: 5');
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mockedComponent.find('.reset').simulate('click');
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assert(currentCountElement.text() === 'Current Count: 0');
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```
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# --seed--
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## --after-user-code--
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```jsx
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ReactDOM.render(<Counter />, document.getElementById('root'))
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```
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## --seed-contents--
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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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# --solutions--
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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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this.increment = this.increment.bind(this);
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this.decrement = this.decrement.bind(this);
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this.reset = this.reset.bind(this);
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}
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reset() {
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this.setState({
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count: 0
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});
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}
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increment() {
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this.setState(state => ({
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count: state.count + 1
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}));
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}
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decrement() {
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this.setState(state => ({
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count: state.count - 1
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}));
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}
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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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