[Bug]: v7_partialHydration with unstable_patchRoutesOnMiss: hydrateFallbackElement not shown on patched routes

[Manizuca]

What version of React Router are you using?

6.25.0

Steps to Reproduce

https://stackblitz.com/edit/github-smnznp?file=package.json,src%2Fapp.tsx

• Have a route that gets patched with unstable_patchRoutesOnMiss
• Enable v7_partialHydration and add hydrateFallbackElement to the root route
• Add some delay to the root loader function

Expected Behavior

The fallback element of the root route is shown while the loaders are executing

Actual Behavior

No fallback is shown

• In the example, load the application at /without-loading-indicator
• For routes defined from the start, it is shown correctly, like /with-loading-indicator

[brophdawg11]

I am not seeing the described behavior. When I load /without-loading-indicator in your stackblitz I see the loading indicator:

[Manizuca]

Hi @brophdawg11
There is apparently a difference between different browsers, when there is a promise that gets immediately resolved. In Firefox i dont get the message, but in chrome i do

I've updated the demo, so the children promise resolves after 10ms instead of 0ms, and now i get the same behaviour in chrome and firefox (the loading indicator is not shown)
https://stackblitz.com/edit/github-smnznp-pcfnbz?file=package.json,src%2Fapp.tsx

[brophdawg11]

This is resolved by #11838 and will be available in the next release 👍

[github-actions]

🤖 Hello there,

We just published version 6.26.0-pre.0 which involves this issue. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 6.26.0 which involves this issue. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!