Comment by twii

I still don't get the need for Promises.. Almost all examples, just like this one in the provided link, talk about solving callback hell with Promises, while callback hell is just a bad way of writing software imao. Look at the code below and please tell me why your example with Promises is a better solution.

  function logAppendResult( err ) {
  	if (err) console.err('Failed to update file');
  	else console.log('Successfully updated file');
  }

  function logWriteResult( err ) {
  	if (err) console.err('Failed to create file');
  	else console.log('Successfully created file');
  }

  function handleFile( filename, fileExists ) {
  	const timestamp = new Date().toISOString();
  	( fileExists )
  		?	fs.appendFile( filename, `Updated file on ${timestamp}\n`, logAppendResult )
  		:	fs.writeFile( filename, `Created file on ${timestamp}\n`, logWriteResult );
  }

  function main() {
    const filename = './example.txt';
    exists( filename, (fileExists) => handleFile(filename, fileExists) );
  }