Support Promises/callbacks from request handlers (#71)

[ajcrites]

For Issue #71

This allows you to return a Promise from a request handler (launch, intent handler, session ending, or audio player events). When the promise resolves, the response is sent. If the promise is rejected, it is treated like an error (e.g. if an error were thrown from the handler).

I have written the code so that it also now supports callbacks in an asynchronous pattern:

skill.intent("intentName", utterances, (req, res, cb) => {
  someAsync(cb);
  return false;
});

Currently you can either return a Promise or false from the handler in order to be asynchronous, but calling the callback makes calling res.send unnecessary.

This is backwards compatible, but I would be in favor of a major version change that supports only promises and just using:

Promise.resolve(handlerResult).then(res.send).catch(handleError);

We can also remove the return false functionality and make either returning a Promise or calling the callback required in order to send the response (or just call response.send() explicitly). I can either do this now as part of this PR or we can move forward with this and remove backwards compatibility later.

[coveralls]

Changes Unknown when pulling 04678a3 on ajcrites:promise/71 into ** on alexa-js:master**.

[coveralls]

Changes Unknown when pulling f7b5a1e on ajcrites:promise/71 into ** on alexa-js:master**.

[dblock]

This is perfect, I'm merging it.

Take a look at code coverage there's one audioplayer scenario that should have a test, but that's not a blocker.

I don't know how I feel about forcing people into a backward incompatible way of doing something that quickly, but I opened #134, you should PR that on top and we can discuss it and see whether it really makes things so much better and whether paying the backwards compat price may be ok.

[dblock]

@ajcrites very nice work, would love to have you on the maintenance team for alexa-app, especially given this change, interested?

[ajcrites]

@dblock I'll take a look at #134 as well. I'd love to be on the maintenance team :D

[chearmstrong]

Really nice solution to this @ajcrites - good work.

[xunxdd]

From my test over and over again, without returning false, alexa would not wait for the callback and therefore deliver any response. It does work locally with the alexa-app-server.

Can you advise?

fb.getOverallData().then(function (data) {
res.say('xxx);
res.shouldEndSession(true);
res.send();
}).catch(function (err) {
res.say('xxx');
res.shouldEndSession(true);
res.send();
});
//return false;

[ajcrites]

return res.send

On Tue, Jul 18, 2017 at 12:21 PM Xun ***@***.***> wrote: From my test over and over again, without returning false, alexa would not wait for the callback and therefore deliver any response. It does work locally with the alexa-app-server. Can you advise? return fb.getOverallData().then(function (data) { res.say('xxx); res.shouldEndSession(true); res.send(); }).catch(function (err) { res.say('xxx'); res.shouldEndSession(true); res.send(); }); //return false; — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#133 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABP2cdI9DKHbTrtInOaT20tsr3IOBTjQks5sPNsJgaJpZM4Lv3ek> .

-- Andrew Crites

[xunxdd]

thanks! let me try it out.

[xunxdd]

No, just tested it, it does not work. again it works locally with the alexa-app-server