exit.js

// The idea. This doesn't work, but basically comes
// from https://github.com/gruntjs/grunt/pull/708
var exitCode;
function exit(code) {
  if (exitCode === undefined) {
    exitcode = code || 0;
    tryToExit();
  }
}

function isDrained(stream) {
  var drained = stream.write('');
  if (!drained) { stream.on('drain', tryToExit); }
  return drained;
}

function tryToExit() {
  if (isDrained(process.stdout) && isDrained(process.stderr)) {
    process.exit(exitCode);
  }
}

// Test code
for (var i = 0; i < 10; i++) {
  console.log("testing %d", i);
}

exit(0);

problem.md

Both of these need to work in Windows, using Node.js 0.8.x and 0.10.x

C:\exit>node exit.js
testing 0
testing 1
testing 2
testing 3
testing 4
testing 5
testing 6
testing 7
testing 8
testing 9

C:\exit>node exit.js | find "t"