callParent() breaks Firefox when using js strict mode

[stefan.lotties]

+1 for strict mode. I hope it was not a design decision to abuse the API and not being able to support strict mode at all.

[mmullany]

The Ext JS 4 class system relies on arguments.caller and we don't see any way to support strict while retaining our class coding convention. We don't plan to change the API in any significant breaking way within the 4.x line, so this isn't on deck for happening in that code line. We're taking a fresh look for future major releases, but after the breakage from 3.x to 4.x, we're becoming extremely sensitive about changing large parts of the Ext API surface all at once.

[AmFernsehturm]

+1 on strict mode for the future.

[Pudge601]

For anyone who stumbles across this issue in hope of a possible way forward, you may find this babel plugin of use.

I wrote it to try to solve this problem by replacing all callParent calls with the direct method call on the parent class' method at compilation time. From there, it should be possible to "use strict", or even use babel to transpile your code from ES2016 syntax (also something which can't be done because of this issue).