test_count_01.js

import React, { Component } from 'react';

class Counter extends Component {
  
  constructor() {
    super();

    this.state = {
      count: 0
    }
  }

  
  increment = () => {
    this.setState(prevState => {
      return {
        count: prevState.count + 1
      }
    });
  }
  
  render() {
    <div>
      <p data-test="test_result">Current Count: {this.state.count}</p>
      <button data-test="increment_button" onClick={this.increment}>Increment Count</button>
    </div>
  }
  
}

export default Counter;