blob: 78d4ecf827c6361fd4932d47835b45c958cf3e33 [file] [log] [blame]
// 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/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
void main() {
group('text contrast guideline', () {
testWidgets('black text on white background - Text Widget - direct style',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('Multiple text with same label', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Column(
children: const <Widget>[
Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
],
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets(
'Multiple text with same label but Nodes excluded from '
'semantic tree have failing contrast should pass a11y guideline ',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Column(
children: const <Widget>[
Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
SizedBox(height: 50),
Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
SizedBox(height: 50),
ExcludeSemantics(
child: Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.white),
),
),
],
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('white text on black background - Text Widget - direct style',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Container(
width: 200.0,
height: 200.0,
color: Colors.black,
child: const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.white),
),
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('White text on white background fails contrast test',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Container(
width: 200.0,
height: 300.0,
color: Colors.white,
child: Column(
children: const <Widget>[
Text(
'this is a white text',
style: TextStyle(fontSize: 14.0, color: Colors.white),
),
SizedBox(height: 50),
Text(
'this is a black text test1',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
SizedBox(height: 50),
Text(
'this is a black text test2',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
],
),
),
),
);
await expectLater(tester, doesNotMeetGuideline(textContrastGuideline));
handle.dispose();
});
const Color surface = Color(0xFFF0F0F0);
/// Shades of blue with contrast ratio of 2.9, 4.4, 4.5 from [surface].
const Color blue29 = Color(0xFF7E7EFB);
const Color blue44 = Color(0xFF5757FF);
const Color blue45 = Color(0xFF5252FF);
const List<TextStyle> textStylesMeetingGuideline = <TextStyle>[
TextStyle(color: blue44, backgroundColor: surface, fontSize: 18),
TextStyle(color: blue44, backgroundColor: surface, fontSize: 14, fontWeight: FontWeight.bold),
TextStyle(color: blue45, backgroundColor: surface),
];
const List<TextStyle> textStylesDoesNotMeetingGuideline = <TextStyle>[
TextStyle(color: blue44, backgroundColor: surface),
TextStyle(color: blue29, backgroundColor: surface, fontSize: 18),
];
Widget appWithTextWidget(TextStyle style) => _boilerplate(
Text('this is text', style: style.copyWith(height: 30.0)),
);
for (final TextStyle style in textStylesMeetingGuideline) {
testWidgets('text with style $style', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(appWithTextWidget(style));
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
}
for (final TextStyle style in textStylesDoesNotMeetingGuideline) {
testWidgets('text with $style', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(appWithTextWidget(style));
await expectLater(tester, doesNotMeetGuideline(textContrastGuideline));
handle.dispose();
});
}
testWidgets('black text on white background - Text Widget - direct style',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.black),
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('white text on black background - Text Widget - direct style',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Container(
width: 200.0,
height: 200.0,
color: Colors.black,
child: const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.white),
),
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('Material text field - amber on amber',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Container(
width: 200.0,
height: 200.0,
color: Colors.amberAccent,
child: TextField(
style: const TextStyle(color: Colors.amber),
controller: TextEditingController(text: 'this is a test'),
),
),
),
);
await expectLater(tester, doesNotMeetGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('Correctly identify failures in complex transforms', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Padding(
padding: const EdgeInsets.only(left: 100),
child: Semantics(
container: true,
child: Padding(
padding: const EdgeInsets.only(left: 100),
child: Semantics(
container: true,
child: Container(
width: 100.0,
height: 200.0,
color: Colors.amberAccent,
child: const Text(
'this',
style: TextStyle(color: Colors.amber),
),
),
),
),
),
),
),
);
await expectLater(tester, doesNotMeetGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('Material text field - default style',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
SizedBox(
width: 100,
child: TextField(
controller: TextEditingController(text: 'this is a test'),
),
),
),
);
await tester.idle();
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
testWidgets('yellow text on yellow background fails with correct message',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Container(
width: 200.0,
height: 200.0,
color: Colors.yellow,
child: const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.yellowAccent),
),
),
),
);
final Evaluation result = await textContrastGuideline.evaluate(tester);
expect(result.passed, false);
expect(
result.reason,
'SemanticsNode#4(Rect.fromLTRB(300.0, 200.0, 500.0, 400.0), '
'label: "this is a test", textDirection: ltr):\n'
'Expected contrast ratio of at least 4.5 but found 1.17 for a font '
'size of 14.0.\n'
'The computed colors was:\n'
'light - Color(0xfffafafa), dark - Color(0xffffeb3b)\n'
'See also: https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html',
);
handle.dispose();
});
testWidgets('label without corresponding text is skipped',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Semantics(
label: 'This is not text',
container: true,
child: const SizedBox(
width: 200.0,
height: 200.0,
child: Placeholder(),
),
),
),
);
final Evaluation result = await textContrastGuideline.evaluate(tester);
expect(result.passed, true);
handle.dispose();
});
testWidgets('offscreen text is skipped', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
Stack(
children: <Widget>[
Positioned(
left: -300.0,
child: Container(
width: 200.0,
height: 200.0,
color: Colors.yellow,
child: const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.yellowAccent),
),
),
),
],
),
),
);
final Evaluation result = await textContrastGuideline.evaluate(tester);
expect(result.passed, true);
handle.dispose();
});
testWidgets('Disabled button is excluded from text contrast guideline',
(WidgetTester tester) async {
// Regression test https://github.com/flutter/flutter/issues/94428
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
_boilerplate(
ElevatedButton(
onPressed: null,
child: Container(
width: 200.0,
height: 200.0,
color: Colors.yellow,
child: const Text(
'this is a test',
style: TextStyle(fontSize: 14.0, color: Colors.yellowAccent),
),
),
),
),
);
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
});
group('custom minimum contrast guideline', () {
Widget iconWidget({
IconData icon = Icons.search,
required Color color,
required Color background,
}) {
return Container(
padding: const EdgeInsets.all(8.0),
color: background,
child: Icon(icon, color: color),
);
}
Widget textWidget({
String text = 'Text',
required Color color,
required Color background,
}) {
return Container(
padding: const EdgeInsets.all(8.0),
color: background,
child: Text(text, style: TextStyle(color: color)),
);
}
Widget rowWidget(List<Widget> widgets) => _boilerplate(Row(children: widgets));
final Finder findIcons = find.byWidgetPredicate((Widget widget) => widget is Icon);
final Finder findTexts = find.byWidgetPredicate((Widget widget) => widget is Text);
final Finder findIconsAndTexts = find.byWidgetPredicate((Widget widget) => widget is Icon || widget is Text);
testWidgets('Black icons on white background', (WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.black, background: Colors.white),
iconWidget(color: Colors.black, background: Colors.white),
]));
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('Black icons on black background', (WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.black, background: Colors.black),
iconWidget(color: Colors.black, background: Colors.black),
]));
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('White icons on black background ("dark mode")',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.white, background: Colors.black),
iconWidget(color: Colors.white, background: Colors.black),
]));
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('Using different icons', (WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.black, background: Colors.white, icon: Icons.more_horiz),
iconWidget(color: Colors.black, background: Colors.white, icon: Icons.description),
iconWidget(color: Colors.black, background: Colors.white, icon: Icons.image),
iconWidget(color: Colors.black, background: Colors.white, icon: Icons.beach_access),
]));
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('One invalid instance fails entire test',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.black, background: Colors.white),
iconWidget(color: Colors.black, background: Colors.black),
]));
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('White on different colors, passing',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.white, background: Colors.red[800]!, icon: Icons.more_horiz),
iconWidget(color: Colors.white, background: Colors.green[800]!, icon: Icons.description),
iconWidget(color: Colors.white, background: Colors.blue[800]!, icon: Icons.image),
iconWidget(color: Colors.white, background: Colors.purple[800]!, icon: Icons.beach_access),
]));
await expectLater(tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)));
});
testWidgets('White on different colors, failing',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.white, background: Colors.red[200]!, icon: Icons.more_horiz),
iconWidget(color: Colors.white, background: Colors.green[400]!, icon: Icons.description),
iconWidget(color: Colors.white, background: Colors.blue[600]!, icon: Icons.image),
iconWidget(color: Colors.white, background: Colors.purple[800]!, icon: Icons.beach_access),
]));
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('Absence of icons, passing', (WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[]));
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('Absence of icons, passing - 2nd test',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
textWidget(color: Colors.black, background: Colors.white),
textWidget(color: Colors.black, background: Colors.black),
]));
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
});
testWidgets('Guideline ignores widgets of other types',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.black, background: Colors.white),
iconWidget(color: Colors.black, background: Colors.white),
textWidget(color: Colors.black, background: Colors.white),
textWidget(color: Colors.black, background: Colors.black),
]));
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findTexts)),
);
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findIconsAndTexts)),
);
});
testWidgets('Custom minimum ratio - Icons', (WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.blue, background: Colors.white),
iconWidget(color: Colors.black, background: Colors.white),
]));
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findIcons, minimumRatio: 3.0)),
);
});
testWidgets('Custom minimum ratio - Texts', (WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
textWidget(color: Colors.blue, background: Colors.white),
textWidget(color: Colors.black, background: Colors.white),
]));
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findTexts)),
);
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findTexts, minimumRatio: 3.0)),
);
});
testWidgets(
'Custom minimum ratio - Different standards for icons and texts',
(WidgetTester tester) async {
await tester.pumpWidget(rowWidget(<Widget>[
iconWidget(color: Colors.blue, background: Colors.white),
iconWidget(color: Colors.black, background: Colors.white),
textWidget(color: Colors.blue, background: Colors.white),
textWidget(color: Colors.black, background: Colors.white),
]));
await expectLater(
tester,
doesNotMeetGuideline(CustomMinimumContrastGuideline(finder: findIcons)),
);
await expectLater(
tester,
meetsGuideline(CustomMinimumContrastGuideline(finder: findTexts, minimumRatio: 3.0)),
);
});
});
group('tap target size guideline', () {
testWidgets('Tappable box at 48 by 48', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(
SizedBox(
width: 48.0,
height: 48.0,
child: GestureDetector(onTap: () {}),
),
));
await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
handle.dispose();
});
testWidgets('Tappable box at 47 by 48', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(
SizedBox(
width: 47.0,
height: 48.0,
child: GestureDetector(onTap: () {}),
),
));
await expectLater(
tester,
doesNotMeetGuideline(androidTapTargetGuideline),
);
handle.dispose();
});
testWidgets('Tappable box at 48 by 47', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(
SizedBox(
width: 48.0,
height: 47.0,
child: GestureDetector(onTap: () {}),
),
));
await expectLater(
tester,
doesNotMeetGuideline(androidTapTargetGuideline),
);
handle.dispose();
});
testWidgets('Tappable box at 48 by 48 shrunk by transform',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(
Transform.scale(
scale: 0.5, // should have new height of 24 by 24.
child: SizedBox(
width: 48.0,
height: 48.0,
child: GestureDetector(onTap: () {}),
),
),
));
await expectLater(
tester,
doesNotMeetGuideline(androidTapTargetGuideline),
);
handle.dispose();
});
testWidgets('Too small tap target fails with the correct message',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(
SizedBox(
width: 48.0,
height: 47.0,
child: GestureDetector(onTap: () {}),
),
));
final Evaluation result = await androidTapTargetGuideline.evaluate(tester);
expect(result.passed, false);
expect(
result.reason,
'SemanticsNode#4(Rect.fromLTRB(376.0, 276.5, 424.0, 323.5), '
'actions: [tap]): expected tap '
'target size of at least Size(48.0, 48.0), '
'but found Size(48.0, 47.0)\n'
'See also: https://support.google.com/accessibility/android/answer/7101858?hl=en',
);
handle.dispose();
});
testWidgets('Box that overlaps edge of window is skipped',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
final Widget smallBox = SizedBox(
width: 48.0,
height: 47.0,
child: GestureDetector(onTap: () {}),
);
await tester.pumpWidget(
MaterialApp(
home: Stack(
children: <Widget>[
Positioned(
left: 0.0,
top: -1.0,
child: smallBox,
),
],
),
),
);
final Evaluation overlappingTopResult = await androidTapTargetGuideline.evaluate(tester);
expect(overlappingTopResult.passed, true);
await tester.pumpWidget(
MaterialApp(
home: Stack(
children: <Widget>[
Positioned(
left: -1.0,
top: 0.0,
child: smallBox,
),
],
),
),
);
final Evaluation overlappingLeftResult = await androidTapTargetGuideline.evaluate(tester);
expect(overlappingLeftResult.passed, true);
await tester.pumpWidget(
MaterialApp(
home: Stack(
children: <Widget>[
Positioned(
bottom: -1.0,
child: smallBox,
),
],
),
),
);
final Evaluation overlappingBottomResult = await androidTapTargetGuideline.evaluate(tester);
expect(overlappingBottomResult.passed, true);
await tester.pumpWidget(
MaterialApp(
home: Stack(
children: <Widget>[
Positioned(
right: -1.0,
child: smallBox,
),
],
),
),
);
final Evaluation overlappingRightResult = await androidTapTargetGuideline.evaluate(tester);
expect(overlappingRightResult.passed, true);
handle.dispose();
});
testWidgets('Does not fail on mergedIntoParent child',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(MergeSemantics(
child: Semantics(
container: true,
child: SizedBox(
width: 50.0,
height: 50.0,
child: Semantics(
container: true,
child: GestureDetector(
onTap: () {},
child: const SizedBox(width: 4.0, height: 4.0),
),
),
),
),
)));
final Evaluation overlappingRightResult = await androidTapTargetGuideline.evaluate(tester);
expect(overlappingRightResult.passed, true);
handle.dispose();
});
testWidgets('Does not fail on links', (WidgetTester tester) async {
Widget textWithLink() {
return Builder(
builder: (BuildContext context) {
return RichText(
text: TextSpan(
children: <InlineSpan>[
const TextSpan(text: 'See examples at '),
TextSpan(
text: 'flutter repo',
recognizer: TapGestureRecognizer()..onTap = () {},
),
],
),
);
},
);
}
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(textWithLink()));
await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
handle.dispose();
});
});
group('Labeled tappable node guideline', () {
testWidgets('Passes when node is labeled', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(Semantics(
container: true,
onTap: () {},
label: 'test',
child: const SizedBox(width: 10.0, height: 10.0),
)));
final Evaluation result = await labeledTapTargetGuideline.evaluate(tester);
expect(result.passed, true);
handle.dispose();
});
testWidgets('Fails if long-press has no label',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(Semantics(
container: true,
onLongPress: () {},
label: '',
child: const SizedBox(width: 10.0, height: 10.0),
)));
final Evaluation result = await labeledTapTargetGuideline.evaluate(tester);
expect(result.passed, false);
handle.dispose();
});
testWidgets('Fails if tap has no label', (WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(Semantics(
container: true,
onTap: () {},
label: '',
child: const SizedBox(width: 10.0, height: 10.0),
)));
final Evaluation result = await labeledTapTargetGuideline.evaluate(tester);
expect(result.passed, false);
handle.dispose();
});
testWidgets('Passes if tap is merged into labeled node',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(_boilerplate(Semantics(
container: true,
onLongPress: () {},
label: '',
child: Semantics(
label: 'test',
child: const SizedBox(width: 10.0, height: 10.0),
),
)));
final Evaluation result = await labeledTapTargetGuideline.evaluate(tester);
expect(result.passed, true);
handle.dispose();
});
});
testWidgets('regression test for material widget',
(WidgetTester tester) async {
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(MaterialApp(
theme: ThemeData.light(),
home: Scaffold(
backgroundColor: Colors.white,
body: ElevatedButton(
style: ElevatedButton.styleFrom(
backgroundColor: const Color(0xFFFBBC04),
elevation: 0,
),
onPressed: () {},
child: const Text('Button', style: TextStyle(color: Colors.black)),
),
),
));
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();
});
}
Widget _boilerplate(Widget child) =>
MaterialApp(home: Scaffold(body: Center(child: child)));