flutter_flutter/packages/flutter/test/widgets/align_test.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Align smoke test', (WidgetTester tester) async {
    await tester.pumpWidget(Align(alignment: const Alignment(0.50, 0.50), child: Container()));

    await tester.pumpWidget(Align(child: Container()));

    await tester.pumpWidget(const Align(alignment: Alignment.topLeft));
    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.rtl,
        child: Align(alignment: AlignmentDirectional.topStart),
      ),
    );
    await tester.pumpWidget(const Align(alignment: Alignment.topLeft));
  });

  testWidgets('Align control test (LTR)', (WidgetTester tester) async {
    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.ltr,
        child: Align(
          alignment: AlignmentDirectional.topStart,
          child: SizedBox(width: 100.0, height: 80.0),
        ),
      ),
    );

    expect(tester.getTopLeft(find.byType(SizedBox)).dx, 0.0);
    expect(tester.getBottomRight(find.byType(SizedBox)).dx, 100.0);

    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.ltr,
        child: Align(alignment: Alignment.topLeft, child: SizedBox(width: 100.0, height: 80.0)),
      ),
    );

    expect(tester.getTopLeft(find.byType(SizedBox)).dx, 0.0);
    expect(tester.getBottomRight(find.byType(SizedBox)).dx, 100.0);
  });

  testWidgets('Align control test (RTL)', (WidgetTester tester) async {
    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.rtl,
        child: Align(
          alignment: AlignmentDirectional.topStart,
          child: SizedBox(width: 100.0, height: 80.0),
        ),
      ),
    );

    expect(tester.getTopLeft(find.byType(SizedBox)).dx, 700.0);
    expect(tester.getBottomRight(find.byType(SizedBox)).dx, 800.0);

    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.ltr,
        child: Align(alignment: Alignment.topLeft, child: SizedBox(width: 100.0, height: 80.0)),
      ),
    );

    expect(tester.getTopLeft(find.byType(SizedBox)).dx, 0.0);
    expect(tester.getBottomRight(find.byType(SizedBox)).dx, 100.0);
  });

  testWidgets('Shrink wraps in finite space', (WidgetTester tester) async {
    final GlobalKey alignKey = GlobalKey();
    await tester.pumpWidget(
      SingleChildScrollView(
        child: Align(key: alignKey, child: const SizedBox(width: 10.0, height: 10.0)),
      ),
    );

    final Size size = alignKey.currentContext!.size!;
    expect(size.width, equals(800.0));
    expect(size.height, equals(10.0));
  });

  testWidgets('Align widthFactor', (WidgetTester tester) async {
    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.ltr,
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[Align(widthFactor: 0.5, child: SizedBox(height: 100.0, width: 100.0))],
        ),
      ),
    );
    final RenderBox box = tester.renderObject<RenderBox>(find.byType(Align));
    expect(box.size.width, equals(50.0));
  });

  testWidgets('Align heightFactor', (WidgetTester tester) async {
    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.ltr,
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Align(heightFactor: 0.5, child: SizedBox(height: 100.0, width: 100.0)),
          ],
        ),
      ),
    );
    final RenderBox box = tester.renderObject<RenderBox>(find.byType(Align));
    expect(box.size.height, equals(50.0));
  });
}