Patch: Adds public to PatchOperation<T> class for testing

Microsoft.Azure.Cosmos/src/Patch/PatchOperation{T}.cs

@@ -10,7 +10,7 @@ namespace Microsoft.Azure.Cosmos
     /// Defines PatchOperation with a value parameter.
     /// </summary>
     /// <typeparam name="T">Data type of value provided for PatchOperation.</typeparam>
-    internal abstract class PatchOperation<T> : PatchOperation
+    public abstract class PatchOperation<T> : PatchOperation
     {
         /// <summary>
         /// Value parameter.

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/PatchOperationTests.cs → Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Patch/PatchOperationTests.cs

@@ -2,10 +2,11 @@
 // Copyright (c) Microsoft Corporation.  All rights reserved.
 //------------------------------------------------------------
 
-namespace Microsoft.Azure.Cosmos.Tests
+namespace Microsoft.Azure.Cosmos.Tests.Patch
 {
     using System;
     using System.IO;
+    using Microsoft.Azure.Cosmos;
     using Microsoft.VisualStudio.TestTools.UnitTesting;
 
     [TestClass]
@@ -21,7 +22,7 @@ public void ThrowsOnNullArguement()
                 PatchOperation.Add(null, "1");
                 Assert.Fail();
             }
-            catch(ArgumentNullException ex)
+            catch (ArgumentNullException ex)
             {
                 Assert.AreEqual(ex.ParamName, "path");
             }
@@ -48,7 +49,7 @@ public void ConstructPatchOperationTest()
             PatchOperationTests.ValidateOperations(operation, PatchOperationType.Add, current);
 
             dynamic complexObject = new { a = "complex", b = 12.34, c = true };
-            operation = PatchOperation.Add(path,  complexObject);
+            operation = PatchOperation.Add(path, complexObject);
             PatchOperationTests.ValidateOperations(operation, PatchOperationType.Add, complexObject);
 
             operation = PatchOperation.Remove(path);
@@ -61,7 +62,7 @@ public void ConstructPatchOperationTest()
             Guid guid = new Guid();
             operation = PatchOperation.Set(path, guid);
             PatchOperationTests.ValidateOperations(operation, PatchOperationType.Set, guid);
-            
+
             operation = PatchOperation.Set<object>(path, null);
             PatchOperationTests.ValidateOperations<object>(operation, PatchOperationType.Set, null);
         }
@@ -100,7 +101,7 @@ private static void ValidateOperations<T>(PatchOperation patchOperation, PatchOp
 
         private class CustomSerializer : CosmosSerializer
         {
-            private CosmosSerializer cosmosSerializer = new CosmosJsonDotNetSerializer();
+            private readonly CosmosSerializer cosmosSerializer = new CosmosJsonDotNetSerializer();
 
             public override T FromStream<T>(Stream stream)
             {
@@ -109,7 +110,7 @@ public override T FromStream<T>(Stream stream)
 
             public override Stream ToStream<T>(T input)
             {
-                return this.cosmosSerializer.ToStream<T>(input);
+                return this.cosmosSerializer.ToStream(input);
             }
         }
     }

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Patch/PatchOperation{T}Tests.cs

@@ -0,0 +1,65 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos.Tests.Patch
+{
+    using System;
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+    [TestClass]
+    public class PatchOperationTTests
+    {
+        private const string path = "/random";
+
+        [TestMethod]
+        public void CastPatchOperationTest()
+        {
+            PatchOperation operation = PatchOperation.Add(path, "test_string");
+            PatchOperation<string> addStringOp = AssertCanCast<string>(operation);
+            Assert.AreEqual("test_string", addStringOp?.Value);
+
+            DateTime dateTime = new DateTime(2022, 8, 1);
+            operation = PatchOperation.Add(path, dateTime);
+            PatchOperation<DateTime> addDateTimeOp = AssertCanCast<DateTime>(operation);
+            Assert.AreEqual(dateTime, addDateTimeOp?.Value);
+
+            var complexObject = new { a = "complex", b = 12.34, c = true };
+            operation = PatchOperation.Add(path, complexObject);
+            dynamic addDynamicOp = operation;
+            Assert.AreEqual("complex", addDynamicOp.Value.a);
+            Assert.AreEqual(12.34, addDynamicOp.Value.b);
+            Assert.AreEqual(true, addDynamicOp.Value.c);
+
+            int[] arrayObject = { 1, 2, 3 };
+            operation = PatchOperation.Replace(path, arrayObject);
+            PatchOperation<int[]> replaceOp = AssertCanCast<int[]>(operation);
+            Assert.AreEqual(arrayObject, replaceOp.Value);
+
+            Guid guid = new Guid();
+            operation = PatchOperation.Set(path, guid);
+            PatchOperation<Guid> setGuidOp = AssertCanCast<Guid>(operation);
+            Assert.AreEqual(guid, setGuidOp.Value);
+
+            operation = PatchOperation.Set<object>(path, null);
+            PatchOperation<object> setObjectOp = AssertCanCast<object>(operation);
+            Assert.AreEqual(null, setObjectOp.Value);
+
+            operation = PatchOperation.Increment(path, 7.0);
+            PatchOperation<double> incrementDoubleOp = AssertCanCast<double>(operation);
+            Assert.AreEqual(7.0, incrementDoubleOp.Value);
+
+            operation = PatchOperation.Increment(path, 40);
+            PatchOperation<long> incrementIntOp = AssertCanCast<long>(operation);
+            Assert.AreEqual(40, incrementIntOp.Value);
+        }
+
+        private static PatchOperation<TPatchData> AssertCanCast<TPatchData>(PatchOperation operation)
+        {
+            PatchOperation<TPatchData> castedOp = operation as PatchOperation<TPatchData>;
+            Assert.IsNotNull(castedOp, $"{nameof(PatchOperation)} should be castable to {nameof(PatchOperation<TPatchData>)}");
+
+            return castedOp;
+        }
+    }
+}