Using .return() causes promise to be resolved as an empty object in 2.9.31

[jviotti]

I'm suddenly having an issue with .return() in exactly 2.9.31.

exports.has = (name, callback) ->
    exports.get(name).return(true)
    .catch errors.ResinApplicationNotFound, ->
        return false
    .nodeify(callback)

If exports.get() resolves, then the promise is resolved as an empty object {} instead of true.

Switching to .then() fixes the issue:

exports.has = (name, callback) ->
    exports.get(name).then ->
        return true
    .catch errors.ResinApplicationNotFound, ->
        return false
    .nodeify(callback)

I've created a branch in my project (https://github.com/resin-io/resin-sdk/tree/issue/bluebird-return) locking to 2.9.31 which reproduces the issue (reverting to 2.9.30 fixes the issue).

$ git clone https://github.com/resin-io/resin-sdk
$ cd resin-sdk
$ git checkout issue/bluebird-return
$ gulp test

By running the test suite you should get something like:

 2 failing
  1) Application Model: .has() given an application should eventually be true:
     AssertionError: expected {} to be true


  2) Device Model: .has() given the device should eventually be true:
     AssertionError: expected {} to be true

Application Model .has() function definition: https://github.com/resin-io/resin-sdk/blob/issue/bluebird-return/lib/models/application.coffee#L104.
Application Model .has() failing test: https://github.com/resin-io/resin-sdk/blob/issue/bluebird-return/tests/models/application.spec.coffee#L123.
Device model .has() function definition: https://github.com/resin-io/resin-sdk/blob/issue/bluebird-return/lib/models/device.coffee#L180.
Device Model .has() failing test: https://github.com/resin-io/resin-sdk/blob/issue/bluebird-return/tests/models/device.spec.coffee#L332.

[benjamingr]

@jviotti any help you can offer in isolating this issue to a more reduced test case would be greatly appreciated.

[petkaantonov]

$ git clone https://github.com/resin-io/resin-sdk
$ cd resin-sdk
$ git checkout issue/bluebird-return
$ npm install
$ gulp test
[22:07:13] Requiring external module coffee-script/register
[22:07:13] Warning: gulp version mismatch:
[22:07:13] Global gulp is 3.9.0
[22:07:13] Local gulp is 3.8.11
[22:07:13] Using gulpfile ~/resin-sdk/gulpfile.coffee
[22:07:13] Starting 'test'...


  102 passing (712ms)

[22:07:16] Finished 'test' after 2.3 s

Also between 2.9.31 and 2.9.30 there isn't any change that could cause anything like this

[petkaantonov]

Ok the error comes when I use node 0.10 or node 0.12 (I was initially using io.js 2.3).

[petkaantonov]

Ok this is because in older node.js, the domain functions are not running in strict mode (this is milestoned for 0.13.1).

Bluebird uses an optimization where values are ferried in the this value of functions - this is fine because bluebirds functions are in strict mode. However, the 2.9.31 version introduced a fix where all functions are bound to domain properly - because these domain bound functions run in non-strict before 0.13.1, primitives will get wrapped I.E. the test is failing because it's actually a wrapped true valued Boolean object.

This demonstrates what is happening:

(function() {

    function DomainBind(fn) {
        return function() {
            return fn.call(this);
        }
    }

    var func = function() {
        "use strict";
        return this;
    };

    var boundFunc = DomainBind(func);

    var result = boundFunc.call(true);

    console.log(result instanceof Boolean); // true
    console.log(result === true); // false

    var strictResult = func.call(true);

    console.log(strictResult instanceof Boolean); // false
    console.log(strictResult === true); // true
})();

[petkaantonov]

Fixed in 2.9.32

[myndzi]

I'm actually having an issue with the domains change and the traceview module. I'm inclined to put the fault with traceview since it's by nature meddling with bluebird's workings, but perhaps this issue applies after all.

/var/www/sites-backend/node_modules/bluebird/js/main/promise.js:367
                domain === null ? fulfill : domain.bind(fulfill);
                                                   ^
TypeError: Cannot read property 'bind' of undefined
    at Promise._addCallbacks (/var/www/sites-backend/node_modules/bluebird/js/main/promise.js:367:52)
    at Promise.ns_addCallbacks [as _addCallbacks] (/var/www/sites-backend/node_modules/@eros/app-framework/node_modules/traceview/node_modules/cls-bluebird/shim.js:18:34)
    at Promise._then (/var/www/sites-backend/node_modules/bluebird/js/main/promise.js:227:32)
    at Promise._passThroughHandler (/var/www/sites-backend/node_modules/bluebird/js/main/finally.js:84:17)
    at Promise.tap (/var/www/sites-backend/node_modules/bluebird/js/main/finally.js:96:17)
    at module.exports (/var/www/sites-backend/node_modules/@eros/app-framework/lib/index.js:74:6)

I don't actually know anything about domains, but maybe you can spot what's wrong so I can add it to my ticket with appneta?

[petkaantonov]

They are calling the internal _addCallbacks method incorrectly from

at Promise.ns_addCallbacks [as _addCallbacks] (/var/www/sites-backend/node_modules/@eros/app-framework/node_modules/traceview/node_modules/cls-bluebird/shim.js:18:34)

[petkaantonov]

return _addCallbacks.call(this, fulfill, reject, progress, promise, receiver);

should be

return _addCallbacks.call(this, fulfill, reject, progress, promise, receiver, null);

in https://github.com/TimBeyer/cls-bluebird/blob/master/shim.js#L18

[myndzi]

That would explain it, thanks!