testing library

Test helpers for the catalog the generator produced.

A generated CatalogItem is a contract with a model: these components exist, they take these properties, and this is what the app does with them. The schema half of that contract is checked at build time. This library checks the other half — what the rendered component exposes to the person using it — by recording the semantics of each item's example and failing when they change.

The recorded file is the same shape A2UI's rendering cases are written in, so it doubles as the answer to "what can the model make this app announce", which is not visible from a Dart diff.

// test/genui_semantics_test.dart
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:genui_gen/testing.dart';
import 'package:my_app/genui_catalog.g.dart';

void main() {
  testWidgets('the catalog exposes what it did before', (tester) async {
    final recorded = <String, List<GenUiSemanticNode>>{};
    for (final item in genUiCatalog.items) {
      final handle = tester.ensureSemantics();
      await tester.pumpWidget(
        MaterialApp(
          home: Scaffold(
            body: GenUiExampleSurface(catalog: genUiCatalog, item: item),
          ),
        ),
      );
      await tester.pumpAndSettle();
      recorded[item.name] = genUiRenderedSemantics();
      handle.dispose();
    }

    expect(
      genUiSemanticsGolden(recorded, File('test/genui_semantics.json')),
      isNull,
    );
  });
}

Record the file the first time, and after a deliberate change, by setting GENUI_UPDATE_GOLDENS=1:

GENUI_UPDATE_GOLDENS=1 flutter test test/genui_semantics_test.dart