How to mock second call?

[RomanKapshuk]

How to mock the second call of function?
E.g, I have the function, that calls API, and in case if it fails we are trying to make the same call and then expecting fine answer?

  final api = Api();


  Info _getRemoteInfo() async {

    try {
      final result = await api.getInfo(); // should throw Exception
      return result;
    } catch (ex) {
     // Do some stuff to fix the api issue;
      final result = await api.getInfo(); // should return Info object
      return result;  
    }

  }

[srawlins]

In GitHub comments, make sure to put code examples in Markdown codeblocks. The easiest way to do this for your code above is to wrap your example in triple-backticks:

```dart
final api = Api();
...
```

When you stub a method call like when(foo.bar()).thenReturn(7), then 7 will be returned every time bar() is called, including the first, second, ...

[RomanKapshuk]

@srawlins Thanks.
Ok, but what about to make the ability to add a sequence of expected values?
Something like

when(foo.bar()).thenReturn([1, 2, 3]);
when(foo.bar()).thenAnswer([() async => 1, () async => 2, () async => 3]);
etc..

So on every new call of bar() method – it will returns next value in the list?

final mockedFoo = MockedFoo();

test('', () {
when(mockedFoo.bar()).thenReturn([1, 2, 3]);

final firstResult = mockedFoo.bar(); // 1
final secondResult = mockedFoo.bar(); // 2
final thirdResult = mockedFoo.bar(); // 3

});

[srawlins]

Mockito doesn't have a mechanism for that, but I could see us adding something like thenReturnInOrder and thenAnswerInOrder.

For now, use a variable declared outside the "answer" response.

var callCount = 0;
when(mockedFoo.bar()).thenAnswer((_) => [1, 2, 3][callCount++]);

But make it more readable :P

[RomanKapshuk]

@srawlins Sure, it would be awesome! Thanks!

[KohlsAdrian]

Mockito doesn't have a mechanism for that, but I could see us adding something like thenReturnInOrder and thenAnswerInOrder.

For now, use a variable declared outside the "answer" response.

var callCount = 0;
when(mockedFoo.bar()).thenAnswer((_) => [1, 2, 3][callCount++]);

But make it more readable :P

That's a godlike solution

[MJablonskiCodespot]

Here's extension for it:

import 'package:mockito/mockito.dart';

extension When<T> on PostExpectation<T> {
  void thenAnswerInOrder(List<T> values) {
    int callCount = 0;
    thenAnswer((_) => values[callCount++]);
  }
}

And usage:

final ChannelsDao channelsDao = MockChannelsDao();
final List<Channel> apiChannels = [MockChannel()];
final List<Channel> emptyChannelLis = [];
when(channelsDao.getAll()).thenAnswerInOrder([
      Future.value(emptyChannelLis),
      Future.value(apiChannels),
    ]);