How can automated accessibility testing be integrated into a Flutter app's test suite to catch accessibility regressions before they reach production?

Flutter's testing framework includes accessibility specific test utilities, such as the ability to check whether every tappable element meets minimum size guidelines or whether text contrast meets recommended thresholds, and integrating these accessibility checks directly into an automated widget test suite means a regression, such as a newly added icon button that is too small or a new color combination with insufficient contrast, can be caught automatically during continuous integration, well before it would otherwise reach real users in production.

testWidgets('meets accessibility guidelines', (tester) async {
  await tester.pumpWidget(MyApp());
  final handle = tester.ensureSemantics();
  await expectLater(tester, meetsGuideline(textContrastGuideline));
  handle.dispose();
});