public async Task EveryOtherRequestFailsAsync(int pageSize, int pages)
{
var allData = Enumerable.Range(0, pages * pageSize).ToArray();
var source = new DataSource <int>(allData, FailPassSequence);
var collection = new IncrementalLoadingCollection <DataSource <int>, int>(source, pageSize);
var requests = new List <Task>();
var willFail = true;
for (var submitedRequests = 0; submitedRequests < pages * 2; submitedRequests++)
{
if (willFail)
{
requests.Add(Assert.ThrowsExceptionAsync <AggregateException>(collection.LoadMoreItemsAsync(0).AsTask));
}
else
{
requests.Add(collection.LoadMoreItemsAsync(0).AsTask().ContinueWith(t => Assert.IsTrue(t.IsCompletedSuccessfully)));
}
willFail = !willFail;
}
await Task.WhenAll(requests);
CollectionAssert.AreEqual(allData, collection);
}
public async Task LoadMoreItemsAsync_LoadsMoreExpectedItemsFromDataSource(uint initialCount, uint count)
{
var data = GetSampleData();
var dataSource = CreateMockDataSource(data);
var collection = new IncrementalLoadingCollection <object>(dataSource);
await collection.LoadMoreItemsAsync(initialCount);
await collection.LoadMoreItemsAsync(count);
var expectedData = data.Take((int)(initialCount + count));
Assert.Equal(expectedData, collection.ToArray());
}
public async Task LoadMoreItemsAsync_OnlySupportsOneLoadOperationAtOnce()
{
var loadingTaskSource = new TaskCompletionSource <IEnumerable <object> >();
var mockDataSource = CreateMockDataSource(GetSampleData());
mockDataSource
.Arrange(dataSource => dataSource.GetItemsAsync(Arg.IsAny <uint>(), Arg.IsAny <uint>()))
.Returns(loadingTaskSource.Task);
var collection = new IncrementalLoadingCollection <object>(mockDataSource);
collection.LoadMoreItemsAsync(1);
await Assert.ThrowsAsync <InvalidOperationException>(async() => await collection.LoadMoreItemsAsync(1));
}
public async Task LoadMoreItemsAsync_ReturnsNumberOfItemsLoaded(uint count, uint expectedCount)
{
var collection = new IncrementalLoadingCollection <object>(CreateMockDataSource(GetSampleData()));
var result = await collection.LoadMoreItemsAsync(count);
Assert.Equal(expectedCount, result.Count);
}
public async Task <bool> RefreshAsync()
{
try
{
if (DataList.IsBusy)
{
return(false);
}
PageIndex = DEFAULT_PAGE_INDEX;
DataList = new IncrementalLoadingCollection <T>(count =>
{
return(GetIncrementalListData(PageIndex++));
});
await DataList.LoadMoreItemsAsync(DEFAULT_PER_PAGE);
return(true);
}
catch (Exception e)
{
var task = ExceptionHelper.WriteRecordAsync(e, nameof(DataViewModelBase <T>), nameof(RefreshAsync));
return(false);
}
}
public async Task <bool> RefreshAsync()
{
try
{
if (DataList.IsBusy)
{
return(false);
}
PageIndex = DEFAULT_PAGE_INDEX;
DataList = new IncrementalLoadingCollection <T>(count =>
{
return(GetIncrementalListData(PageIndex++));
});
await DataList.LoadMoreItemsAsync(DEFAULT_PER_PAGE);
return(true);
}
catch (Exception e)
{
var task = Logger.LogAsync(e);
return(false);
}
}
public async Task FirstRequestFails()
{
var source = new DataSource <int>(AllData, DataSource <int> .ThrowException);
var collection = new IncrementalLoadingCollection <DataSource <int>, int>(source, PageSize);
await Assert.ThrowsExceptionAsync <AggregateException>(collection.LoadMoreItemsAsync(0).AsTask);
Assert.IsTrue(!collection.Any());
var requests = new List <Task>();
for (int pageNum = 1; pageNum <= Pages; pageNum++)
{
requests.Add(collection.LoadMoreItemsAsync(0).AsTask()
.ContinueWith(t => Assert.IsTrue(t.IsCompletedSuccessfully)));
}
await Task.WhenAll(requests);
CollectionAssert.AreEqual(AllData, collection);
}
public async Task Requests(params int[] pageDelays)
{
var source = new DataSource <int>(AllData, pageDelays.Select(DataSource <int> .MakeDelayOp));
var collection = new IncrementalLoadingCollection <DataSource <int>, int>(source, PageSize);
for (int pageNum = 1; pageNum <= Pages; pageNum++)
{
await collection.LoadMoreItemsAsync(0);
CollectionAssert.AreEqual(Enumerable.Range(0, PageSize * pageNum).ToArray(), collection);
}
}
public async Task HasMoreItems_ReturnsTrueWhileDataStillInSource(int dataSourceCount, bool expectedHasMoreItems, uint[] countsToLoad)
{
var data = GetSampleData(dataSourceCount);
var dataSource = CreateMockDataSource(data);
var collection = new IncrementalLoadingCollection <object>(dataSource);
foreach (var countToLoad in countsToLoad)
{
await collection.LoadMoreItemsAsync(countToLoad);
}
Assert.Equal(expectedHasMoreItems, collection.HasMoreItems);
}
public async Task EveryOtherRequestFails()
{
var source = new DataSource <int>(AllData, FailPassSequence);
var collection = new IncrementalLoadingCollection <DataSource <int>, int>(source, PageSize);
var willFail = true;
for (int submitedRequests = 0; submitedRequests < Pages * 2; submitedRequests++)
{
if (willFail)
{
await Assert.ThrowsExceptionAsync <AggregateException>(collection.LoadMoreItemsAsync(0).AsTask);
}
else
{
await collection.LoadMoreItemsAsync(0);
}
willFail = !willFail;
}
CollectionAssert.AreEqual(AllData, collection);
}
public async Task RequestsAsync(params int[] pageDelays)
{
var source = new DataSource <int>(AllData, pageDelays.Select(DataSource <int> .MakeDelayOp));
var collection = new IncrementalLoadingCollection <DataSource <int>, int>(source, PageSize);
var requests = new List <Task>();
for (int pageNum = 1; pageNum <= Pages; pageNum++)
{
requests.Add(collection.LoadMoreItemsAsync(0).AsTask()
.ContinueWith(t => Assert.IsTrue(t.IsCompletedSuccessfully)));
}
await Task.WhenAll(requests);
CollectionAssert.AreEqual(AllData, collection);
}