The flutter_test package should not import Material or Cupertino. One problem that this has caused is given in flutter/packages@79aecdd. By importing flutter/material.dart and checking is Tooltip, the find.byTooltip method in flutter_test is not usable in material_ui. Its Tooltip is different from the on in flutter/flutter, so that check always returns false.

We already have an analyzer tool that checks for cross imports in our tests (check_tests_cross_imports.dart). We should expand it to also check flutter_test.

Currently it looks like there are only 3 violations in flutter_test, but having this analyzer check will also be valuable to prevent regressions in the future.