Importing neon-animation into a page that already uses web animations polyfill causes breaking errors

[madeleineostoja]

Including neon-animation.html into a page that already has a web animations polyfill loaded causes breaking errors (cannot read property 'cancel' of null).

Removing the web-animations.html import from neon-animation fixes the problem. Should neon-animation check if features are available before importing a polyfill?

Minimal repro: https://jsbin.com/tutonabali/edit?html,js,console,output

EDIT: seems to only error on Chrome.

[dstoc]

I can't see the issue in your repro, but this sounds like this issue which was fixed in 2.2.1

[madeleineostoja]

Hmm repro is still erroring for me:

Assume the Polygit import there is at least 2.2.1?

Chrome 51.0.2704.103 on OSX

[madeleineostoja]

Looks like this is caused by https://github.com/web-animations/web-animations-js/issues/88