Uncaught ReferenceError: Promise is not defined

Question

A Chrome App I've made works perfectly fine for me, but another user gets an error Uncaught ReferenceError: Promise is not defined when starting it up. For some reason it doesn't understand what a Promise is. The code works perfectly fine on my end and I've never gotten that error before, but the user gets it every time. What could be the issue here?

Solution 1

The user updated Chrome to the latest version and that apparently fixed it. I don't know how, since his version was from December 2013 and surely Promises worked back then. I don't know. It definitely isn't a problem with the code since I'm running the same exact version the user is running and I've never encountered that error.

But yeah - apparently fixed.

EDIT: Apparently Promises only work since Chrome 32, so yeah that's why the error.

Solution 2

To support IE and older versions of other browsers, you should consider loading a polyfill for the Promise object.

One implementation you can use out of the box with a <script> tag is available here.

Comments

[Benjamin Gruenbaum]

I would not use native promises (yet) if I were you, you're much safer using a library like Bluebird.

[Fabis]

What do you mean? Why not?

[Benjamin Gruenbaum]

They're unstable and only provide a fragment of the functionality libraries do. They exist to interoperate with user code cleanly, not to replace libraries.