public async Task NextPageTwice_ReturnsSecondPageAsync()
{
// arrange
var iterator = new TwitterPageIterator <ITwitterResult <long>, string>(null, _getNextPage, _extractNextCursor, _isLastPage);
// 1st iteration
await iterator.NextPageAsync();
// act
var result = await iterator.NextPageAsync();
// assert
Assert.Equal("cursor_for_page_3", result.NextCursor);
Assert.Equal("cursor_for_page_3", iterator.NextCursor);
Assert.True(result.IsLastPage);
Assert.True(iterator.Completed);
Assert.Same(result.Content, _secondPage);
}
public async Task NextPage_WhenAlreadyCompleted_ThrowsExceptionAsync()
{
// arrange
A.CallTo(() => _isLastPage(_firstPage)).Returns(true);
var iterator = new TwitterPageIterator <ITwitterResult <long>, string>(null, _getNextPage, _extractNextCursor, _isLastPage);
// 1st iteration
await iterator.NextPageAsync();
// act - assert
await Assert.ThrowsAsync <TwitterIteratorAlreadyCompletedException>(async() => await iterator.NextPageAsync());
Assert.Equal("cursor_for_page_2", iterator.NextCursor);
Assert.True(iterator.Completed);
}
public async Task NextPage_ReturnsPageFromLambdaAsync()
{
// arrange
var iterator = new TwitterPageIterator <ITwitterResult <long>, string>(null, _getNextPage, _extractNextCursor, _isLastPage);
// act
var result = await iterator.NextPageAsync();
// assert
Assert.Equal("cursor_for_page_2", result.NextCursor);
Assert.Equal("cursor_for_page_2", iterator.NextCursor);
Assert.False(result.IsLastPage);
Assert.False(iterator.Completed);
Assert.Same(result.Content, _firstPage);
}
