Nested router resets (?) causes "flickering" (not found tab appearing)

[matanshukry]

Describe the bug

tl&dr: I'm seeing a "not found" tab for a quick second, for the 1st time, instead of the expected route.

In the reproducible app that follow, ther are 2 flows:

1. initialPath is /articles -> go to /article/:id -> click back
2. initialPath is /books -> go to /articles -> go to /article/:id -> click back

On the 1st everything seems fine. On the 2nd, we can see there's a "not found" page in between, probably for the nested. It only happens in this flow, and only for the 1st time.

Flow #1 / Articles start - which works well:

https://github.com/slovnicki/beamer/assets/5613042/86f75d4e-f0f8-4b07-b4cc-960958f8381d

Flow #2 / books start - where we can see the issue:

https://github.com/slovnicki/beamer/assets/5613042/5a809872-fce6-4fdd-b0c4-ec14b143de31

Beamer version: (e.g. v0.14.1, master, ...) v1.5.5

To Reproduce Steps to reproduce the behavior:

1. Go to https://github.com/matanshukry/case325 , and clone the repo
2. Go to my_app.dart, and change initialPath to /books (Flow #2).
3. Start the app
4. Click on the "books" tab (the right one)
5. Click on one of the items
6. Issue: at this point while transitioning, if you use time dilation for example, you should see a "not found" page for a brief second.
7. Click back (android back button)
8. Issue: at this point while transitioning, if you use time dilation for example, you should see a "not found" page for a brief second.

To clarify, if you do the same flow without restarting the app - there is no "not found" page. It seems to only happen for the 1st time.

Expected behavior The routes should be shown without a "not found" in betweem them.

Screenshots Added videos before, should be enough.

Desktop (please complete the following information):

• OS: N/a
• Browser: N/A
• Version: N/A

Smartphone (please complete the following information):

• Device: Android simulator
• OS: Pixel 6 API 30
• Browser N/A, but stock browser probably
• Version: API 30

Additional context Add any other context about the problem here.

[fieryboa]

I'm facing a similar issue too. It looks like this happens when you nest beamers. When try to navigate to a route which is handled by a BeamLocation in the parent beamer from the inner beamer, the inner beamer's BeamLocations also try to resolve the route, which ends up failing.

example:

1. RootLocation consists of two paths, /books and /articles
2. BooksLocation consists of a path, /books/:id

There are two nested beamers, where the outer beamer uses RootLocation and the inner beamer uses BooksLocation. When you are in, say, /books/123 and try to navigate to /articles, both BooksLocation and RootLocation try to resolve /articles. It succeeds in RootLocation but fails in BooksLocation.

In my case, this happens all the time when i try to navigate from an inner beamer, not just once. For now, I managed to side step the issue by returning a BeamPage whose child is a SizedBox.shrink in the inner BeamLocation. There are no errors (or the not found page) and the widget tree as seen via the dev tools seems to be fine too.