improve DefaultSerializationContextTest

src/csharp/Grpc.Core.Tests/Internal/DefaultSerializationContextTest.cs

@@ -17,9 +17,6 @@
 #endregion
 
 using System;
-using System.Buffers;
-using System.Collections.Generic;
-using System.Runtime.InteropServices;
 using Grpc.Core;
 using Grpc.Core.Internal;
 using Grpc.Core.Utils;
@@ -32,23 +29,29 @@ namespace Grpc.Core.Internal.Tests
         [TestCase]
         public void CompleteAllowedOnlyOnce()
         {
-            var context = new DefaultSerializationContext();
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
                 var buffer = GetTestBuffer(10);
 
                 context.Complete(buffer);
                 Assert.Throws(typeof(InvalidOperationException), () => context.Complete(buffer));
                 Assert.Throws(typeof(InvalidOperationException), () => context.Complete());
             }
+        }
 
         [TestCase]
         public void CompleteAllowedOnlyOnce2()
         {
-            var context = new DefaultSerializationContext();
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
 
                 context.Complete();
                 Assert.Throws(typeof(InvalidOperationException), () => context.Complete(GetTestBuffer(10)));
                 Assert.Throws(typeof(InvalidOperationException), () => context.Complete());
             }
+        }
 
         [TestCase(0)]
         [TestCase(1)]
@@ -57,7 +60,9 @@ namespace Grpc.Core.Internal.Tests
         [TestCase(1000)]
         public void ByteArrayPayload(int payloadSize)
         {
-            var context = new DefaultSerializationContext();
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
                 var origPayload = GetTestBuffer(payloadSize);
 
                 context.Complete(origPayload);
@@ -65,6 +70,7 @@ namespace Grpc.Core.Internal.Tests
                 var nativePayload = context.GetPayload().ToByteArray();
                 CollectionAssert.AreEqual(origPayload, nativePayload);
             }
+        }
 
         [TestCase(0)]
         [TestCase(1)]
@@ -73,7 +79,9 @@ namespace Grpc.Core.Internal.Tests
         [TestCase(1000)]
         public void BufferWriter_OneSegment(int payloadSize)
         {
-            var context = new DefaultSerializationContext();
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
                 var origPayload = GetTestBuffer(payloadSize);
 
                 var bufferWriter = context.GetBufferWriter();
@@ -84,6 +92,28 @@ namespace Grpc.Core.Internal.Tests
                 var nativePayload = context.GetPayload().ToByteArray();
                 CollectionAssert.AreEqual(origPayload, nativePayload);
             }
+        }
+
+        [TestCase(0)]
+        [TestCase(1)]
+        [TestCase(10)]
+        [TestCase(100)]
+        [TestCase(1000)]
+        public void BufferWriter_OneSegment_GetMemory(int payloadSize)
+        {
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
+                var origPayload = GetTestBuffer(payloadSize);
+
+                var bufferWriter = context.GetBufferWriter();
+                origPayload.AsSpan().CopyTo(bufferWriter.GetMemory(payloadSize).Span);
+                bufferWriter.Advance(payloadSize);
+
+                var nativePayload = context.GetPayload().ToByteArray();
+                CollectionAssert.AreEqual(origPayload, nativePayload);
+            }
+        }
 
         [TestCase(1, 4)]  // small slice size tests grpc_slice with inline data
         [TestCase(10, 4)]
@@ -95,7 +125,9 @@ namespace Grpc.Core.Internal.Tests
         [TestCase(1000, 64)]
         public void BufferWriter_MultipleSegments(int payloadSize, int maxSliceSize)
         {
-            var context = new DefaultSerializationContext();
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
                 var origPayload = GetTestBuffer(payloadSize);
 
                 var bufferWriter = context.GetBufferWriter();
@@ -112,24 +144,49 @@ namespace Grpc.Core.Internal.Tests
                 
                 var nativePayload = context.GetPayload().ToByteArray();
                 CollectionAssert.AreEqual(origPayload, nativePayload);
-
-            context.GetPayload().Dispose(); // TODO: do it better.. (use the scope...)
             }
+        }
+
+        [TestCase]
+        public void ContextIsReusable()
+        {
+            using (var scope = NewDefaultSerializationContextScope())
+            {
+                var context = scope.Context;
 
-        // AdjustTailSpace(0) if previous tail size is 0....
+                var origPayload1 = GetTestBuffer(10);
+                context.Complete(origPayload1);
+                CollectionAssert.AreEqual(origPayload1, context.GetPayload().ToByteArray());
 
-        // test that context.Complete() call is required...
+                context.Reset();
+
+                var origPayload2 = GetTestBuffer(20);
+    
+                var bufferWriter = context.GetBufferWriter();
+                origPayload2.AsSpan().CopyTo(bufferWriter.GetMemory(origPayload2.Length).Span);
+                bufferWriter.Advance(origPayload2.Length);
+                CollectionAssert.AreEqual(origPayload2, context.GetPayload().ToByteArray());
 
-        // BufferWriter.GetMemory... (add refs to the original memory?)
+                context.Reset();
 
-        // TODO: set payload and then get IBufferWriter should throw?
+                // TODO: that's should be a null payload...
+                CollectionAssert.AreEqual(new byte[0], context.GetPayload().ToByteArray());
+            }
+        }
 
-        // TODO: test Reset()...
+        //test ideas:
 
-        // TODO: destroy SliceBufferSafeHandles... (use usagescope...)
+        // test that context.Complete() call is required...
 
+        // set payload with Complete([]) and then get IBufferWriter should throw (because it's been completed already?)
 
+        // other ideas:
+        // AdjustTailSpace(0) if previous tail size is 0... (better for SliceBufferSafeHandle)
 
+        private DefaultSerializationContext.UsageScope NewDefaultSerializationContextScope()
+        {
+            return new DefaultSerializationContext.UsageScope(new DefaultSerializationContext());
+        }
 
         private byte[] GetTestBuffer(int length)
         {