如何为 Cupertino 数据选择器运行颤振小部件测试？答案

【问题标题】：How can I run a flutter widget test for cupertino data picker?如何为 Cupertino 数据选择器运行颤振小部件测试？
【发布时间】：2021-09-02 04:17:08
【问题描述】：

我正在尝试为 cupertino 日期选择器编写测试，但我找不到任何结果。如何为小部件测试选择一个特定的日期时间。

testWidgets("description", (WidgetTester tester)async{
    await tester.pumpWidget(MaterialApp(home: MyPage()));

    final textField=find.byKey(Key("nameTextField"));
    final datePicker=find.byKey(Key("birthDatePicker"));
    final button=find.byType(ElevatedButton);


    await tester.enterText(textField, "not important");
    await tester.drag(datePicker, Offset(0.0, 10.0)); ///Here the problem ?

    await tester.press(button);

    await tester.pump();
    expect(find.text("Error Text"), findsOneWidget);
  });

我的问题是，如何选择 1/1/2021 进行小部件测试？

【问题讨论】：

标签： flutter flutter-test

【解决方案1】：

查看为小部件实施的测试，这些测试结果是不言自明的。他们倾向于在整个文本中使用参考，并以恒定的偏移量进行动作。

https://github.com/flutter/flutter/blob/master/packages/flutter/test/cupertino/date_picker_test.dart

下面我也给你举个例子

testWidgets('picker automatically scrolls away from invalid date on day change', (WidgetTester tester) async {
      late DateTime date;
      await tester.pumpWidget(
        CupertinoApp(
          home: Center(
            child: SizedBox(
              height: 400.0,
              width: 400.0,
              child: CupertinoDatePicker(
                mode: CupertinoDatePickerMode.date,
                onDateTimeChanged: (DateTime newDate) {
                  date = newDate;
                },
                initialDateTime: DateTime(2018, 2, 27), // 2018 has 28 days in Feb.
              ),
            ),
          ),
        ),
      );

      await tester.drag(find.text('27'), const Offset(0.0, -32.0), touchSlopY: 0.0, warnIfMissed: false); // see top of file
      await tester.pump();
      expect(
        date,
        DateTime(2018, 2, 28),
      );

      await tester.drag(find.text('28'), const Offset(0.0, -32.0), touchSlopY: 0.0, warnIfMissed: false); // see top of file
      await tester.pump(); // Once to trigger the post frame animate call.

      // Callback doesn't transiently go into invalid dates.
      expect(
        date,
        DateTime(2018, 2, 28),
      );
      // Momentarily, the invalid 29th of Feb is dragged into the middle.
      expect(
        tester.getTopLeft(find.text('2018')).dy,
        tester.getTopLeft(find.text('29')).dy,
      );

      await tester.pump(); // Once to start the DrivenScrollActivity.
      await tester.pump(const Duration(milliseconds: 500));

      expect(
        date,
        DateTime(2018, 2, 28),
      );
      expect(
        tester.getTopLeft(find.text('2018')).dy,
        tester.getTopLeft(find.text('28')).dy,
      );
    });

【讨论】：

非常感谢你，我还没有测试你的答案，但我可以看到逻辑，它必须工作:)
不客气，虽然这对我来说也是合乎逻辑的，但我在拖动功能的行为方面遇到了问题，而不是真正的运动。如果您也是这种情况，您可以使用以下解决方法await tester.dragFrom(tester.getCenter(find.text(now.year.toString())), const Offset(0.0, 50.0));