public async Task Test_No_Previous_Comic_When_Current_Is_First()
{
//Arrange
int mockId = 1;
int?previousValidId = null;
var mockComicApi = new Mock <IXKCDApi>();
mockComicApi.Setup(api => api.GetFirstComicId())
.ReturnsAsync(GetValidMockedFirstComicId());
mockComicApi.Setup(api => api.GetComicOfTheDay())
.ReturnsAsync(GetValidMockedComicOfTheDay());
mockComicApi.Setup(api => api.GetComicById(previousValidId ?? default))
.ReturnsAsync(GetInvalidComic());
var comicRepository = new ComicRepository(mockComicApi.Object);
//Act
var result = await comicRepository.GetPreviousComicId(mockId);
var previousComic = await comicRepository.GetComicById(previousValidId ?? default);
var firstComicId = await comicRepository.GetFirstComicId();
//Assert
Assert.Null(result);
Assert.Equal(previousValidId, result);
Assert.Null(previousComic);
Assert.Equal(firstComicId, mockId);
}
public async Task Test_Previous_Valid_Comic_When_Current_Is_Not_First()
{
//Arrange
int mockId = 406;
int previousValidId = 403;
var mockComicApi = new Mock <IXKCDApi>();
mockComicApi.Setup(api => api.GetFirstComicId())
.ReturnsAsync(GetValidMockedFirstComicId());
mockComicApi.Setup(api => api.GetComicOfTheDay())
.ReturnsAsync(GetValidMockedComicOfTheDay());
mockComicApi.Setup(api => api.GetComicById(404))
.ReturnsAsync(GetInvalidComic());
mockComicApi.Setup(api => api.GetComicById(405))
.ReturnsAsync(GetInvalidComic());
mockComicApi.Setup(api => api.GetComicById(previousValidId))
.ReturnsAsync(GetMockedComicById(previousValidId));
var comicRepository = new ComicRepository(mockComicApi.Object);
//Act
var result = await comicRepository.GetPreviousComicId(mockId);
var previousComic = await comicRepository.GetComicById(previousValidId);
//Assert
Assert.NotNull(result);
Assert.Equal(previousValidId, result);
Assert.NotNull(previousComic);
Assert.Equal(previousComic.Num, result);
Assert.Equal($"Testing {result.Value}", previousComic.Alt);
Assert.Equal($"Test comic {result.Value}", previousComic.SafeTitle);
Assert.Equal($"Test comic {result.Value}", previousComic.Title);
mockComicApi.Verify(mock => mock.GetComicById(mockId - 1), Times.Once());
mockComicApi.Verify(mock => mock.GetComicById(mockId - 2), Times.Once());
//Because of the fetch during the act
mockComicApi.Verify(mock => mock.GetComicById(previousValidId), Times.Exactly(2));
mockComicApi.Verify(mock => mock.GetComicById(mockId - 4), Times.Never());
}
public async Task Test_No_Next_Comic_When_Current_Is_Invalid()
{
//Arrange
int mockId = 10000;
int?nextValidId = null;
var mockComicApi = new Mock <IXKCDApi>();
mockComicApi.Setup(api => api.GetFirstComicId())
.ReturnsAsync(GetValidMockedFirstComicId());
mockComicApi.Setup(api => api.GetComicOfTheDay())
.ReturnsAsync(GetValidMockedComicOfTheDay());
mockComicApi.Setup(api => api.GetComicById(mockId))
.ReturnsAsync(GetInvalidComic());
var comicRepository = new ComicRepository(mockComicApi.Object);
//Act
var result = await comicRepository.GetPreviousComicId(mockId);
//Assert
Assert.Null(result);
Assert.Equal(nextValidId, result);
mockComicApi.Verify(mock => mock.GetComicById(mockId + 1), Times.Never());
}
