public async Task ValidatesReadArguments()
{
var buffer = Encoding.UTF8.GetBytes("some data");
var stream = new ReadOnlyMemoryStream(buffer);
stream.Seek(3, SeekOrigin.Begin);
var read = new byte[buffer.Length - stream.Position];
Assert.That(
async() => await stream.ReadAsync(read, 0, buffer.Length),
Throws.InstanceOf <ArgumentException>());
Assert.That(
async() => await stream.ReadAsync(null, 0, buffer.Length),
Throws.InstanceOf <ArgumentException>());
Assert.That(
async() => await stream.ReadAsync(read, -1, read.Length),
Throws.InstanceOf <ArgumentException>());
Assert.That(
async() => await stream.ReadAsync(read, 0, -1),
Throws.InstanceOf <ArgumentException>());
await stream.ReadAsync(read, 0, read.Length);
Assert.AreEqual(
new ReadOnlyMemory <byte>(buffer, 3, buffer.Length - 3).ToArray(),
read);
}
public async Task CanSeek()
{
var buffer = Encoding.UTF8.GetBytes("some data");
var stream = new ReadOnlyMemoryStream(buffer);
stream.Seek(5, SeekOrigin.Begin);
Assert.AreEqual(buffer[5], stream.ReadByte());
stream.Seek(1, SeekOrigin.Current);
Assert.AreEqual(buffer[7], stream.ReadByte());
stream.Seek(-2, SeekOrigin.End);
Assert.AreEqual(buffer.Length - 2, stream.Position);
Assert.AreEqual(buffer[buffer.Length - 2], stream.ReadByte());
stream.Seek(-2, SeekOrigin.End);
var read = new byte[buffer.Length - stream.Position];
await stream.ReadAsync(read, 0, read.Length);
Assert.AreEqual(
new ReadOnlyMemory <byte>(buffer, buffer.Length - 2, 2).ToArray(),
read);
}