added tests

Source/MQTTnet.AspnetCore/SpanBasedMqttPacketBodyReader.cs

@@ -24,7 +24,6 @@ namespace MQTTnet.AspNetCore
 
         public byte ReadByte()
         {
-            ValidateReceiveBuffer(1);
             return _buffer.Span[_offset++];
         }
 
@@ -35,9 +34,7 @@ namespace MQTTnet.AspNetCore
 
         public ushort ReadUInt16()
         {
-            ValidateReceiveBuffer(2);
-
-            var result = BinaryPrimitives.ReadUInt16BigEndian(_buffer.Span);
+            var result = BinaryPrimitives.ReadUInt16BigEndian(_buffer.Span.Slice(_offset));
             _offset += 2;
             return result;
         }
@@ -49,23 +46,14 @@ namespace MQTTnet.AspNetCore
 
         private ReadOnlySpan<byte> ReadSegmentWithLengthPrefix()
         {
-            var length = ReadUInt16();
+            var span = _buffer.Span;
+            var length = BinaryPrimitives.ReadUInt16BigEndian(span.Slice(_offset));
 
-            ValidateReceiveBuffer(length);
-
-            var result = _buffer.Slice(_offset, length).Span;
-            _offset += length;
+            var result = span.Slice(_offset+2, length);
+            _offset += 2 + length;
             return result;
         }
-
-        private void ValidateReceiveBuffer(ushort length)
-        {
-            if (_buffer.Length < _offset + length)
-            {
-                throw new ArgumentOutOfRangeException(nameof(_buffer), $"expected at least {_offset + length} bytes but there are only {_buffer.Length} bytes");
-            }
-        }
-
+        
         public unsafe string ReadStringWithLengthPrefix()
         {
             var buffer = ReadSegmentWithLengthPrefix();

Tests/MQTTnet.AspNetCore.Tests/MqttPacketSerializerTests.cs

@@ -0,0 +1,17 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Core.Tests;
+using MQTTnet.Serializer;
+
+namespace MQTTnet.AspNetCore.Tests
+{
+    [TestClass]
+    public class MqttPacketSerializerTestsWithSpanBasedReader : MqttPacketSerializerTests
+    {
+        protected override IPacketBodyReader ReaderFactory(byte[] data)
+        {
+            var result = new SpanBasedMqttPacketBodyReader();
+            result.SetBuffer(data);
+            return result;
+        }
+    }
+}

Tests/MQTTnet.Core.Tests/MqttPacketSerializer_Tests.cs

@@ -528,7 +528,12 @@ namespace MQTTnet.Tests
             Assert.AreEqual(expectedBase64Value, Convert.ToBase64String(Join(data)));
         }
 
-        private static void DeserializeAndCompare(MqttBasePacket packet, string expectedBase64Value, MqttProtocolVersion protocolVersion = MqttProtocolVersion.V311)
+        protected virtual IMqttPacketBodyReader ReaderFactory(byte[] data)
+        {
+            return new MqttPacketBodyReader(data, 0, data.Length);
+        }
+
+        private void DeserializeAndCompare(MqttBasePacket packet, string expectedBase64Value, MqttProtocolVersion protocolVersion = MqttProtocolVersion.V311)
         {
             IMqttPacketFormatter serializer;
             if (protocolVersion == MqttProtocolVersion.V311)