fromCallback with multiArgs throws an error when callback is called without arguments.

[an-sh]

Currently when fromCallback (with multiArgs : true) callback function is
called without any arguments, like cb(), bluebird throws the following error:

Unhandled rejection RangeError: Invalid array length
    at /app/available_modules/1459505274000/bluebird/js/release/nodeback.js:44:53
    at fn1 (eval at <anonymous> (/app/index.js:715:19), <anonymous>:3:3)
    at capture.Promise.fromCallback.multiArgs (eval at <anonymous> (/app/index.js:715:19), <anonymous>:36:7)
    at tryCatcher (/app/available_modules/1459505274000/bluebird/js/release/util.js:16:23)
    at Function.Promise.fromNode.Promise.fromCallback (/app/available_modules/1459505274000/bluebird/js/release/promise.js:176:30)
    at eval (eval at <anonymous> (/app/index.js:715:19), <anonymous>:35:24)
    at GeneratorFunctionPrototype.next (native)
    at /app/index.js:573:32
    at GeneratorFunctionPrototype.next (native)
    at iterate (/app/index.js:587:77)
    at module.exports (/app/index.js:601:19)
    at eval (/app/index.js:697:5)
    at Object.<anonymous> (/app/index.js:710:3)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)

This doesn't happen neither if callback is called like cb(null), nor
when multiArgs is false.

Here is a demonstration snippet:
https://tonicdev.com/56fd394c96866f11009cfcd1/56fe47f6a404b41100ae1aa5

[HCanber]

I was about to report the same bug for bluebird@3.3.4.

Here is a shorter working example, this time using promisify

const fn = Promise.promisify(cb => cb(), { multiArgs: true })
fn()

The problem in nodeback.js is because INLINE_SLICE cannot handle the case when arguments is empty, i.e. has length 0:
INLINE_SLICE(args, arguments, 1)

The generated code is:

var $_len = arguments.length;var args = new Array($_len - 1); for(var $_i = 1; $_i < $_len; ++$_i) {args[$_i - 1] = arguments[$_i];}; 

i.e. it's trying to create an array of size -1 which causes a RangeError: Invalid array length.

Two possible solutions: INLINE_SLICE is changed or nodeback.js is updated:

function nodebackForPromise(promise, multiArgs) {
    return function(err, value) {
        if (promise === null) return;
        if (err) {
            var wrapped = wrapAsOperationalError(maybeWrapAsError(err));
            promise._attachExtraTrace(wrapped);
            promise._reject(wrapped);
        } else if (!multiArgs) {
            promise._fulfill(value);
+       } else if (arguments.length === 0) {
+           promise._fulfill();
        } else {
            INLINE_SLICE(args, arguments, 1);
            promise._fulfill(args);
        }
        promise = null;
    };
}

[HCanber]

I was about to report the same bug for bluebird@3.3.4.

Here is a shorter working example, this time using promisify

const fn = Promise.promisify(cb => cb(), { multiArgs: true })
fn()

The problem in nodeback.js is because INLINE_SLICE cannot handle the case when arguments is empty, i.e. has length 0:
INLINE_SLICE(args, arguments, 1)

The generated code is:

var $_len = arguments.length;var args = new Array($_len - 1); for(var $_i = 1; $_i < $_len; ++$_i) {args[$_i - 1] = arguments[$_i];}; 

i.e. it's trying to create an array of size -1 which causes a RangeError: Invalid array length.

Two possible solutions: INLINE_SLICE is changed or nodeback.js is updated:

function nodebackForPromise(promise, multiArgs) {
    return function(err, value) {
        if (promise === null) return;
        if (err) {
            var wrapped = wrapAsOperationalError(maybeWrapAsError(err));
            promise._attachExtraTrace(wrapped);
            promise._reject(wrapped);
        } else if (!multiArgs) {
            promise._fulfill(value);
+       } else if (arguments.length === 0) {
+           promise._fulfill();
        } else {
            INLINE_SLICE(args, arguments, 1);
            promise._fulfill(args);
        }
        promise = null;
    };
}