public void stream_can_seek_from_begin()
{
Stream testStream = GetTestStream();
long origin = testStream.Position = testStream.Length / 2;
Action action;
const long length = 500L;
using (var s = new RegionStream(testStream, length))
{
s.Position.Should().Be(0, "because a region stream starts at 0");
action = () => s.Seek(-10, SeekOrigin.Begin);
action.Should().Throw <IOException>("because offset is less then 0");
s.Position.Should().Be(0, "because position should not have changed");
s.BaseStream.Position.Should().Be(origin);
s.Seek(50, SeekOrigin.Begin);
s.Position.Should().Be(50);
s.BaseStream.Position.Should().Be(origin + 50);
s.Seek(100, SeekOrigin.Begin);
s.Position.Should().Be(100);
s.BaseStream.Position.Should().Be(origin + 100);
action = () => s.Seek(length + 50, SeekOrigin.Begin);
action.Should().Throw <IOException>("because offset exceeds end of stream");
s.Position.Should().Be(100, "because position should not have changed");
s.BaseStream.Position.Should().Be(origin + 100);
}
}
public void stream_starts_at_start()
{
const long length = 200L;
using (var s = new RegionStream(GetTestStream(), length))
{
s.Position.Should().Be(0, "because a region stream starts at 0");
s.BaseStream.Position.Should().Be(0, "because the base stream started at 0");
s.Length.Should().Be(length, "because a region stream has a fixed length of {0}", length);
}
}
public void stream_starts_in_middle()
{
const long position = 100L;
const long length = 200L;
using (var s = new RegionStream(GetTestStream(position), length))
{
s.Position.Should().Be(0, "because a region stream starts at 0");
s.BaseStream.Position.Should().Be(position, "because a region stream starts at {0}", position);
s.Length.Should().Be(length, "because a region stream has a fixed length of {0}", length);
}
}
