How to test an entire Flutter app for consistency?

Is there any way to automate testing possible paths for the app and check if each state satisfies a specific condition?

Two examples so you can understand what I mean:

• I have a custom Scaffold that should be present at all times. I'd like to prevent, for instance, adding a new page and forgetting to use the custom Scaffold, so I want to check that, say, for every path, tester.find.byType(CustomScaffold) finds one widget.
• I would like to check that all widgets follow the theme (so as to not accidentally add a widget that has a color that is not in the theme, for instance). This should also work when the user switches themes.

Is such a thing possible? Or would I have to just manually "find" stuff to tap in a page and create some sort of depth-limited tree?