refluxjs: asyncResult action call gives an "Uncaught (in promise)" error

When I call an asyncResult action and when the triggered async process sends back an error (for example: “401 unauthorized”), everything works fine but I get another error in the console: “Uncaught (in promise) … PublisherMethods.js:168”:

var Reflux = require('reflux');

var someActions = Reflux.createActions({
    doThis: {
        asyncResult: true
    },
    // ...
});

someActions.doThis.listen(function (arg) {
    someAsyncProcess(arg)
        .then(this.completed)
        .catch(this.failed);
});

// elsewhere in the app:
someActions.doThis(arg);

// -> if someAsyncProcess sends back an error, another error in the console:
//     "Uncaught (in promise) ... PublisherMethods.js:168"

Am I doing it wrong, or is there a bug in the asyncResult actions ?

About this issue

Original URL
State: closed
Created 9 years ago
Comments: 21 (1 by maintainers)

Most upvoted comments

I was running into this as well and it was driving me batty. I’m pretty sure I know what the issue is, but I’m not sure what the correct solution is. However, there is a workaround you can put in your code to at least prevent the error from popping up in the console.

var Reflux = require('reflux');

var someActions = Reflux.createActions({
    doThis: {
        asyncResult: true
    },
    // ...
});

someActions.doThis.listen(function (arg) {
    someAsyncProcess(arg)
        .then(this.completed)
        .catch(this.failed);
});

// elsewhere in the app:
someActions.doThis(arg).catch(function() { /* prevents "Uncaught (in promise) error */});

The key bit being that catch there at the end.

The problem is that when the “doThis” action is called a promise is setup that listens for “doThis.failed” to be called. Of course, when your “someAsyncProcess” promise gets rejected, the “doThis.failed” gets called as expected. However, that also triggers a reject on the promise that Reflux sets up in the generated function for the action. Because there isn’t a catch setup for that, the promise API throws an error.

I’m still not quite sure I understand why reject is called when the failed child action is triggered as it seems like it should work the other way around. I’m sure there is a good reason for it.

kembuco on Mar 24, 2015