为啥我的状态之一在我的测试期间没有被触发

Posted 2023-02-23

【中文标题】为啥我的状态之一在我的测试期间没有被触发

【英文标题】：Why one of my state is not triggered during my test为什么我的状态之一在我的测试期间没有被触发

【发布时间】：2020-08-22 02:16:38

【问题描述】：

我跟随 Reso code youtube 创建了一个小型天气应用程序，但我也使用了最新的 bloc 库和 flutter_bloc 4.0。

基础应用：https://www.youtube.com/watch?v=hTExlt1nJZI&list=PLB6lc7nQ1n4jCBkrirvVGr5b8rC95VAQ5&index=7

BLoc 测试：https://www.youtube.com/watch?v=S6jFBiiP0Mc&list=PLB6lc7nQ1n4jCBkrirvVGr5b8rC95VAQ5&index=8

前 2 个测试正在运行。例如，下面的没有给我任何错误：

test(
    'NEWER WAY BUT lONG-WINDED emits [WeatherLoading, WeatherLoaded] when successful',
    () 
  when(mockWeatherRepository.fetchWeather(any))
      .thenAnswer((_) async => weather);

  final bloc = WeatherBloc(mockWeatherRepository);

  bloc.add(GetWeather('London'));

  emitsExactly(bloc, [
    WeatherInitial(),
    WeatherLoading(),
    WeatherLoaded(weather),
  ]);
);

由于某种原因，下面的测试不会触发 WeatherInitial。

blocTest(
  'emits [WeatherLoading, WeatherLoaded] when successful',
  build: () async 
    when(mockWeatherRepository.fetchWeather(any))
        .thenAnswer((_) async => weather);

    return WeatherBloc(mockWeatherRepository);
  ,
  act: (bloc) => bloc.add(GetWeather('London')),
  expect: [
    WeatherInitial(),
    WeatherLoading(),
    WeatherLoaded(weather),
  ],
);

错误是：

ERROR: Expected: [
        WeatherInitial:WeatherInitial,
        WeatherLoading:WeatherLoading,
        WeatherLoaded:WeatherLoaded
      ]
Actual: [WeatherLoading:WeatherLoading, WeatherLoaded:WeatherLoaded]
Which: was WeatherLoading:<WeatherLoading> instead of WeatherInitial:<WeatherInitial> at location [0]

你知道为什么吗？

【参考方案1】：

根据官方bloc_test library这个行为是正确的：

skip is an optional int which can be used to skip any number of states.
The default value is 1 which skips the initialState of the bloc. 
skip can be overridden to include the initialState by setting skip to 0.

因此，如果您只想包含“InitialState”，请将“skip”值设置为 0：

.
.
.
skip: 0,
expect: [
    WeatherInitial(),
    WeatherLoading(),
    WeatherLoaded(weather),
  ],