public async Task Should_download_contents_by_parts_of_given_sizes(int contentSize, int partSize)
{
var wholeContent = Enumerable.Range(0, contentSize).Select(x => (byte)(x % byte.MaxValue)).ToArray();
var expectedPartsLoads = wholeContent.Batch(partSize).ToList();
var partsLoads = new List <byte[]>();
await using var stream = await ChunkContentStream.CreateAsync(GetPart, partSize);
var bytes = await stream.ReadAllBytesAsync();
bytes.Should().BeEquivalentTo(wholeContent);
partsLoads.Should().BeEquivalentTo(expectedPartsLoads);
Task <(ArraySegment <byte> contentPart, long totalLength)> GetPart((long from, long to) range)
{
var rangeLength = (int)(range.to - range.from + 1);
rangeLength.Should().BeLessOrEqualTo(partSize).And.BePositive();
var part = wholeContent.Skip((int)range.from).Take(rangeLength).ToArray();
partsLoads.Add(part);
return(Task.FromResult <(ArraySegment <byte> contentPart, long totalLength)>((part, wholeContent.Length)));
}
}
public async Task Should_fail_when_given_invalid_part_size(int partSize)
{
Func <Task> func = async() => await ChunkContentStream.CreateAsync(_ => EmptyPartAsync(), partSize);
await func.Should().ThrowAsync <ArgumentException>();
Task <(ArraySegment <byte> contentPart, long totalLength)> EmptyPartAsync() =>
Task.FromResult <(ArraySegment <byte> contentPart, long totalLength)>((new ArraySegment <byte>(Array.Empty <byte>()), 100));
}