Fixed a bug in IBufferWriterStream.WriteByte

Author: Sergio0694

Microsoft.Toolkit.HighPerformance/Streams/IBufferWriterStream.cs

@@ -158,6 +158,8 @@ public override void WriteByte(byte value)
             MemoryStream.ValidateDisposed(this.disposed);
 
             this.bufferWriter.GetSpan(1)[0] = value;
+
+            this.bufferWriter.Advance(1);
         }
 
         /// <inheritdoc/>

UnitTests/UnitTests.HighPerformance.Shared/Streams/Test_IBufferWriterStream.cs

@@ -24,9 +24,9 @@ public void Test_IBufferWriterStream_Lifecycle()
 
             Stream stream = ((IBufferWriter<byte>)writer).AsStream();
 
-            Assert.IsTrue(stream.CanRead);
+            Assert.IsFalse(stream.CanRead);
             Assert.IsFalse(stream.CanSeek);
-            Assert.IsFalse(stream.CanWrite);
+            Assert.IsTrue(stream.CanWrite);
 
             Assert.ThrowsException<NotSupportedException>(() => stream.Length);
             Assert.ThrowsException<NotSupportedException>(() => stream.Position);