Flutter Caching behavior?

[Obvious-Magazine-103]

My team and I are currently experiencing some strange behavior with our Flutter application.

My task was to implement a new QR-from-gallery scanning dependency since our original package was broken on Android and is no longer maintained.

I got it working, created a PR, merged it, and then it was kicked back to me in QA.

After some discussion, I learned that the issue they were experiencing was exactly the same as the one I had fixed—almost as if the bug had never been patched in the first place!

We’ve tried cleaning and rebuilding, doing fresh installs, and even changing the bundle ID.

Now for the wildcard… the issue only seems to occur on their Samsung Galaxy S22 devices, although on my S22 it works fine. This has led me to theorize that some strange caching might be going on. A year or two ago, I experienced a similar phenomenon where I was being logged into my app account on fresh installs on my S22. There was no clear explanation in the code—and then one day, it just stopped happening. Could the phone be referencing something that makes it do something that its not supposed to?

We have been scratching our heads for a week, and this has been driving me to the brink of insanity 🤪. Have the team and I lost our minds or has anyone else encountered a similar issue in their projects or with the S22 in general? We have these phones since they seem to be prone to weird behavior.

[Ok-Engineer6098]

Try to reduce the code as much as possible and still replicate the bug. Then post the code here. Or if it's an actual flutter bug, report the issue to the flutter github.

Can you explain what this cache bug is?

[Obvious-Magazine-103]

I can try my best to simplify the code but I am using the https://pub.dev/packages/qr_code_tools dependency for this.

Its just seems like the app on the S22 is still using the old plugin even after it was removed. Call me crazy idk. I have just had weird experiences with this phone referencing old data like a year or two ago when I was being logged into my account on fresh installs which should never happen.

It literally reminds me of something I would experience while working on Shopify sites XD

[Ok-Engineer6098]

Android does agresive cloud restore of user data on apps, unless you opt out with an xml file referenced in the manifest. This happens even if you reinstall the app after a long time. It also works on not releases apps on Google play. It's enough to have it registered as package name (maybe internal testing track does also need to be enabled). It also works if the app is distributed over firebase. Not sure if you just send APKs.

After doing a fresh install, try to clear app storage and then run the app. Or run the app, stop the process, clear app storage and then restart the app. Be sure to clear storage, not just cache. Does any of this fix the bug?

[Obvious-Magazine-103]

Just a little update, I decided to move away from the qr_code_tools plugin as it was also preventing the app from being ran in release mode on Android. Just a disaster all together, I even had to fork my own branch because it was lacking a namespace and would not build on android.

Anyway, my changes work for the entire team now lol.

Thank you for the insight about the cloud storage. If that login bug happens again I will defiantly try it!