Material Components: Golden tests

[jpnurmi]

Perhaps we could have a simple golden test that takes screenshots of all pages in the example with the different variants? It's somewhat tedious and error-prone to manually browse the example back and forth with several themes. :)

[jpnurmi]

Intentional theme changes would need to be coupled with flutter test --update-goldens and it would slowly increase the repo size but at least we'd have a better overview of how PRs affect various theme variants and modes... what do you say?

[Feichtmeier]

@Jupi007 couldnts we eventually copy those tests from flutter/flutter for the pure material widgets?

[Jupi007]

@Feichtmeier This will be very heavy to maintain, isn't it?
I think the original JP's idea is better. Btw his code is already working, why didn't he make a PR?

[Feichtmeier]

@Feichtmeier This will be very heavy to maintain, isn't it?
I think the original JP's idea is better. Btw his code is already working, why didn't he make a PR?

I have no idea. Maybe it wasn't finished

[Feichtmeier]

Here is JPs work for future work on this
https://github.com/ubuntu/archive_yaru.dart/pull/320/files