Warning when native promise implementation is replaced with bluebird

[k0pernikus]

In a node application using highland@2.10.1 I have replaced the native promise implemenation with bluebird@3.4 due to performance consideration via:

global.Promise = Bluebird;

While highland seems to be working just as fine as before, I lot of warning with the content:

(node:1428) Warning: a promise was created in a handler at usr/src/marketing-tasks/node_modules/highland/lib/index.js:517:24 but was not returned from it, see http://goo.gl/rRqMUw

The offending code is index.js in line 517:

function promiseStream(promise) {
    if (_.isFunction(promise['finally'])) { // eslint-disable-line dot-notation
        // Using finally handles also bluebird promise cancellation
        return _(function (push) {
            promise.then(function (value) {
                return push(null, value); // it complains here
            },
                function (err) {
                    return push(err);
                })['finally'](function () { // eslint-disable-line dot-notation
                    return push(null, nil);
                });
        });
    }

I am unsure if this is either an issue with how highland.js creates promises or if bluebird's warning system fires a false positive.

This is me asking: Does bluebird's warning has any merit for highland.js? Or should this be an issue on bluebird's side?

[vqvu]

It's a false positive, but we should be able to suppress the warning on our side by just returning null.

[vqvu]

Try out v2.10.2 and let me know if you're still seeing these warnings.