input: Write a function that generates a complete Python backend and React frontend application for managing a list of tasks. The backend should include a Flask web server, an SQLAlchemy database setup, and an API endpoint for creating tasks. The frontend should be a React component that displays the list of tasks and fetches them from the backend API. Provide the necessary code for both the Python backend and the React frontend. Include units tests assert for the backend API.
  
  assert test_create_task_success():
      response = client.post('/tasks', json={'title': 'New Task'})
      assert response.status_code == 200
      assert response.json['title'] == 'New Task'
  
  assert test_create_task_no_title():
      response = client.post('/tasks', json={})
      assert response.status_code == 400
      assert response.json['error'] == 'Title must be provided.'
output: 
  from flask import Flask, request, jsonify
  from flask_sqlalchemy import SQLAlchemy
  
  app = Flask(__name__)
  app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///tasks.db'
  db = SQLAlchemy(app)
  
  class Task(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      title = db.Column(db.String(100), nullable=False)
  
      def to_dict(self):
          return {'id': self.id, 'title': self.title}
  
  @app.route('/tasks', methods=['POST'])
  def create_task():
      data = request.get_json()
      if not data or not data.get('title'):
          return jsonify({'error': 'Title must be provided'}), 400
      new_task = Task(title=data['title'])
      db.session.add(new_task)
      db.session.commit()
      return jsonify(new_task.to_dict()), 200
  