System.IO.Tests.MemoryStreamTests.MemoryStream_CopyTo_Invalid C# (CSharp) Method

        public static void MemoryStream_CopyTo_Invalid()
        {
            MemoryStream memoryStream;
            using (memoryStream = new MemoryStream())
            {
                Assert.Throws<ArgumentNullException>("destination", () => memoryStream.CopyTo(destination: null));
                
                // Validate the destination parameter first.
                Assert.Throws<ArgumentNullException>("destination", () => memoryStream.CopyTo(destination: null, bufferSize: 0));
                Assert.Throws<ArgumentNullException>("destination", () => memoryStream.CopyTo(destination: null, bufferSize: -1));

                // Then bufferSize.
                Assert.Throws<ArgumentOutOfRangeException>("bufferSize", () => memoryStream.CopyTo(Stream.Null, bufferSize: 0)); // 0-length buffer doesn't make sense.
                Assert.Throws<ArgumentOutOfRangeException>("bufferSize", () => memoryStream.CopyTo(Stream.Null, bufferSize: -1));
            }

            // After the Stream is disposed, we should fail on all CopyTos.
            Assert.Throws<ArgumentOutOfRangeException>("bufferSize", () => memoryStream.CopyTo(Stream.Null, bufferSize: 0)); // Not before bufferSize is validated.
            Assert.Throws<ArgumentOutOfRangeException>("bufferSize", () => memoryStream.CopyTo(Stream.Null, bufferSize: -1));

            MemoryStream disposedStream = memoryStream;

            // We should throw first for the source being disposed...
            Assert.Throws<ObjectDisposedException>(() => memoryStream.CopyTo(disposedStream, 1));

            // Then for the destination being disposed.
            memoryStream = new MemoryStream();
            Assert.Throws<ObjectDisposedException>(() => memoryStream.CopyTo(disposedStream, 1));

            // Then we should check whether we can't read but can write, which isn't possible for non-subclassed MemoryStreams.

            // THen we should check whether the destination can read but can't write.
            var readOnlyStream = new DelegateStream(
                canReadFunc: () => true,
                canWriteFunc: () => false
            );

            Assert.Throws<NotSupportedException>(() => memoryStream.CopyTo(readOnlyStream, 1));
        }