shell/keyboard/test/keyboard_test.dart

// Copyright 2016 The Fuchsia 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_test/flutter_test.dart';
import 'package:flutter/services.dart' as services;
import 'package:flutter/widgets.dart';
import 'package:keyboard/keyboard.dart';

final services.AssetBundle _defaultBundle =
    services.NetworkAssetBundle(Uri.base);

void main() {
  testWidgets('tapping "uppercase" symbol swaps to upper case letters',
      (WidgetTester tester) async {
    String onTextText;

    GlobalKey keyboardKey = GlobalKey();
    Keyboard keyboard = Keyboard(
        key: keyboardKey,
        onText: (String text) {
          onTextText = text;
        },
        onSuggestion: (String suggestion) {},
        onDelete: () {},
        onGo: () {});

    await tester.pumpWidget(DefaultAssetBundle(
        bundle: _defaultBundle, child: Center(child: keyboard)));
    expect(onTextText, isNull);

    // tap the center of the keyboard to get a lower case letter
    await _tap(tester, _getCenter(tester, keyboardKey));
    expect(onTextText, isNotNull);
    String testOnTextText = onTextText;

    // tap the shift key to switch the keyboard into the uppercase state
    await _tap(tester, _getShiftPosition(tester, keyboardKey));
    expect(onTextText, testOnTextText);

    // tap the center of the keyboard to get an upper case version of
    // the lower case letter obtained earlier.
    await _tap(tester, _getCenter(tester, keyboardKey));
    expect(onTextText, testOnTextText.toUpperCase());
  });
}

Offset _getShiftPosition(WidgetTester tester, Key keyboardKey) {
  final Finder element = find.byKey(keyboardKey);
  Offset topLeft = tester.getTopLeft(element);
  Offset bottomLeft = tester.getBottomLeft(element);
  return Offset(
      topLeft.dx, topLeft.dy + ((bottomLeft.dy - topLeft.dy) * 0.6));
}

Offset _getCenter(WidgetTester tester, Key key) =>
    tester.getCenter(find.byKey(key));

Future<Null> _tap(WidgetTester tester, Offset point) async {
  TestGesture gesture = await tester.startGesture(point, pointer: 8);
  await tester.pump();
  await gesture.up();
  await tester.pump();
}