Improved IMemoryOwner.AsStream tests

CommunityToolkit · May 7, 2020 · e8a9534 · e8a9534
1 parent bb779f4
commit e8a9534
Showing 1 changed file with 27 additions and 1 deletion.
diff --git a/UnitTests/UnitTests.HighPerformance.Shared/Extensions/Test_IMemoryOwnerExtensions.cs b/UnitTests/UnitTests.HighPerformance.Shared/Extensions/Test_IMemoryOwnerExtensions.cs
@@ -21,7 +21,8 @@ public void Test_IMemoryOwnerExtensions_EmptyIMemoryOwnerStream()
             Stream stream = buffer.AsStream();
 
             Assert.IsNotNull(stream);
-            Assert.AreEqual(stream.Length, buffer.Length);
+            Assert.AreEqual(buffer.Length, 0);
+            Assert.AreEqual(stream.Length, 0);
             Assert.IsTrue(stream.CanWrite);
         }
 
@@ -37,5 +38,30 @@ public void Test_MemoryExtensions_IMemoryOwnerStream()
             Assert.AreEqual(stream.Length, buffer.Length);
             Assert.IsTrue(stream.CanWrite);
         }
+
+        [TestCategory("IMemoryOwnerExtensions")]
+        [TestMethod]
+        public void Test_MemoryExtensions_IMemoryOwnerStream_DoesNotAlterExistingData()
+        {
+            MemoryOwner<byte> buffer = MemoryOwner<byte>.Allocate(1024);
+
+            // Fill the buffer with sample data
+            for (int i = 0; i < buffer.Length; i++)
+            {
+                buffer.Span[i] = unchecked((byte)(i & byte.MaxValue));
+            }
+
+            Stream stream = buffer.AsStream();
+
+            Assert.IsNotNull(stream);
+            Assert.AreEqual(stream.Length, buffer.Length);
+            Assert.IsTrue(stream.CanWrite);
+
+            // Validate that creating the stream doesn't alter the underlying buffer
+            for (int i = 0; i < buffer.Length; i++)
+            {
+                Assert.AreEqual(buffer.Span[i], unchecked((byte)(i & byte.MaxValue)));
+            }
+        }
     }
 }