Sometimes `Transition` renders child instanly

[dokugo]

What package has an issue

@mantine/core

Describe the bug

Sometimes Transition renders child instanly without actually transitioning, this happens when Transition status is currently exited and then its mounted prop value changes from false to true.

Here is the code to reproduce the problem: https://codesandbox.io/p/devbox/mantine-transition-test-next-4dfvdc

Here is the screen recording. I toggle isVisible boolean value by clicking the first button. isVisible is used as the value of mounted Transition prop. After a few toggles the hidden button appears instantly.

https://github.com/mantinedev/mantine/assets/7773972/6d6ecade-7c68-4bc9-af80-5dee2ef9f059

Simulation of fast toggling:

https://github.com/mantinedev/mantine/assets/7773972/f02d2584-e769-486c-b322-dc8c1db66700

I'm not sure why exactly this happens. I tried experimenting with flushSync inside the handleStateChange function here, but without success. https://github.com/mantinedev/mantine/blob/master/src/mantine-core/src/components/Transition/use-transition.ts#L41

What version of @mantine/* packages do you have in package.json? (Note that all @mantine/* packages must have the same version in order to work correctly)

7.1.7

If possible, please include a link to a codesandbox with the reproduced problem

https://codesandbox.io/p/devbox/mantine-transition-test-next-4dfvdc

Do you know how to fix the issue

No

Are you willing to participate in fixing this issue and create a pull request with the fix

None

Possible fix

No response

[ghana7989]

Sandbox link is not working

[dokugo]

@ghana7989 thanks, I fixed the link.

[cyantree]

I think that's the same issue as #3126.

[cyantree]

Please have a look at this comment where I've provided an example using a patched version of the library.

Could you please check whether this resolves the issue for you?

[rtivital]

Fixed in 7.6.1

[fauxparse]

Fixed in 7.6.1

It's still happening in the stories on the Mantine website, FYI :)

[devnaumov]

@rtivital Still happening for the modals manager example on the Mantine website. Modal opens instantly after several attempts.