Fiber-using code after refactoring, take 1. More info at https://www.mixmax.com/blog/node-fibers-using-synchronize-js.

fiber-code-after-refactoring-take-1.js

sync.fiber(function() {
  var processedData = processFile('a.txt');
});

function processFile(filename) {
  var data = sync.await(fs.readFile(fileName, sync.defer()));
  return /* do something with the data */;
}