App.jsx with Button component

App.jsx

import React from "react";
import Question from './components/Question';
import Button from './components/Button';
class App extends React.Component {
  constructor (props) {
    super(props);
    this.state = {
      data: [],
      currentTicket: 0,
      finished: false,
      score: '',
    };
  }

  componentDidMount() {
    this.getData();
  }
  
  getData = () => {
    fetch('/tickets.json').then((response) => {
      return response.json();
    }).then((data) => {
      this.setState({ data });
    });
  }

  nextTicket = () => {
    const { currentTicket, data } = this.state;
    if (currentTicket === data.length -1) {
      return this.setState({ currentTicket: 0 });
    }
    return this.setState({ currentTicket: currentTicket +1 });
  }

  render () {
    const { data, currentTicket } = this.state;
    const question = data && data.length > 0 ? data[currentTicket].question : '';
    return (
      <div>
        <h1>Testas</h1>
        <div>
          <div>
            <Question question={question} />
          </div>
          <div>
            <Button name="Next ticket" handler={() => this.nextTicket} />
          </div>
        </div>
      </div>
    );
  }
}

export default App;