MobX 5 Unsupported IE11

[shealavington]

Describe the bug
Appears that in the latest upgrade, MOBX5 is not supported by IE11 which is really unfortunate.

Error: [mobx] MobX 5+ requires Proxy and Symbol objects. If your environment doesn't support Symbol or Proxy objects, please downgrade to MobX 4. For React Native Android, consider upgrading JSCore.

To Reproduce
Upgrade to the latest version,
Attempt to load SB in IE
Receive error

Expected behavior
Ideally, IE should work.

System
Environment Info:
System:
OS: Windows 10 10.0.19041
CPU: (4) x64 Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz
Binaries:
Node: 10.23.0 [OMITTED_FOR_SECURITY]
npm: 6.14.6 [OMITTED_FOR_SECURITY]
Browsers:
Chrome: [OMITTED_FOR_SECURITY]
Edge: Spartan [OMITTED_FOR_SECURITY]
npmPackages:
@storybook/addon-a11y: ^6.1.2 => 6.1.2
@storybook/addon-actions: ^6.1.2 => 6.1.2
@storybook/addon-console: ^1.2.2 => 1.2.2
@storybook/addon-essentials: ^6.1.2 => 6.1.2
@storybook/addon-links: ^6.1.2 => 6.1.2
@storybook/addon-storysource: ^6.1.2 => 6.1.2
@storybook/addons: ^6.1.2 => 6.1.2
@storybook/theming: ^6.1.2 => 6.1.2
@storybook/vue: ^6.1.2 => 6.1.2

Additional context
I'm aware that still using IE11 is staying behind the times, however, unfortunately, it's a requirement for me for the time being.

[shilman]

Storybook doesn't use MobX, so I'm not sure what's required on our side. WDYT?

[shealavington]

Interesting, I tried to upgrade storybook using the command that popped up on the storybook application.

I ran the command (npx sb update or something similar), then I begun getting MobX errors in IE... Have you tested the latest update on IE11 yourself? Could confirm that it still works? Perhaps I've missed something (Which I don't think that I have)...

Could it be a dependency?

[shilman]

@shealavington we have CI checks running in IE and it's working AFAIK. our CI has been down for a few days, so there's a slim possibility that it broke during that time. There are some other IE-related issues that came up recently, but nothing related to MobX.

[shealavington]

Hmm interesting, I've tried again and I'm still not able to get this working on IE, if I get some time, I'll try to debug and figure it out, if you can confirm that IE is working, then the ticket can be closed... Perhaps the issue is originating elsewhere and MobX seems to be a casualty of that or something. As long as you can confirm IE works for you, I can plan time to upgrade.

Perhaps I've changed something? The setup I'm using is somewhat complex, but only seems impacted on update...

[tooppaaa]

Don't worry @shealavington, it's a pain lots of us have to deal with ;)

There's currently an issue #13302 which should be resolved soon but this doesn't break build or manager build in IE.

If you believe there's anything that can be done on storybook side, please reopen :)

[Baffour]

@shealavington did you ever solve this issue? I'm getting the same error after upgrading to 6.1 using npx sb upgrade

[shealavington]

Nope, I'm still currently using an older version

[Baffour]

@shealavington Just tried the prelease version (npx sb upgrade --prerelease) and it actually works for me now!

There are a couple of cosmetic UI issues with native IE dropdowns/checkboxes showing on controls, and a couple of console errors about syntax highlighting but I can load stories and play with controls. Worth trying that out, something in 6.2 must have fixed the MobX issue

[shealavington]

That's awesome, unfortunately I can't move to a prerelease, however I'll keep the next version in mind, thanks for keeping me updated! 🤝

[shilman]

@tooppaaa any idea why this is working in 6.2 but not in 6.1?

[shealavington]

@tooppaaa any idea why this is working in 6.2 but not in 6.1?

I'll take this as a "We have no idea"? 😂