As wycats says, this indeed supported by good JS promises. I talked a bit more about the situation in my promise-tests documentation: https://github.com/domeni

As wycats says, this indeed supported by good JS promises. I talked a bit more about the situation in my promise-tests documentation: https://github.com/domenic/promise-tests#returning-a-promise-from-a-handler https://github.com/domenic/promise-tests#returning-a-promise... Unfortunately Promises/A omits this, so I didn't address it directly, although I did sneak it into the example code with the `return expandUrlUsingTwitterApi(mostRecentShortUrl);` line.