1. Open your command-line application and navigate to your workspace.
2. Create a new folder named 04-03-async-function-Promise-chain.
3. Copy or create an index.html that loads and runs a main function from main.js.

4. Create an async function, getRandomNumber, that returns a random number:

async function getRandomNumber() { 
  console.log('Getting random number.'); 
  return Math.random(); 
} 

5. Create an async function, determinReadyToLaunch, that returns true if its first argument is greater than 0.5:

async function deteremineReadyToLaunch(percentage) { 
  console.log('Determining Ready to launch.'); 
  return Math.random() > 0.5; 
}  

6. Create a third async function, reportResults, that logs out different results if its first argument is true or false:

async function reportResults(isReadyToLaunch) { 
  if (isReadyToLaunch) { 
    console.log('Rocket ready to launch. Initiate countdown: '); 
  } else { 
    console.error('Rocket not ready. Abort mission: '); 
  } 
}  

7. Create a main function that calls getRandomNumber, and a chain of the Promise it creates to call determineReadyToLaunch and reportResults in succession:

export function main() { 
  console.log('Before Promise created'); 
  getRandomNumber() 
    .then(deteremineReadyToLaunch) 
    .then(reportResults) 
  console.log('After Promise created'); 
}   

8. Start your Python web server and open the following link in your browser: http://localhost:8000/.

9. You should see the following output: