Serializer: Add SDK serializer to Client.ClientOptions.Serializer

Microsoft.Azure.Cosmos/src/CosmosClientOptions.cs

@@ -57,7 +57,7 @@ public class CosmosClientOptions
         /// </summary>
         private int gatewayModeMaxConnectionLimit;
         private CosmosSerializationOptions serializerOptions;
-        private CosmosSerializer serializer;
+        private CosmosSerializer serializerInternal;
 
         private ConnectionMode connectionMode;
         private Protocol connectionProtocol;
@@ -378,7 +378,7 @@ public CosmosSerializationOptions SerializerOptions
         [JsonConverter(typeof(ClientOptionJsonConverter))]
         public CosmosSerializer Serializer
         {
-            get => this.serializer;
+            get => this.serializerInternal;
             set
             {
                 if (this.SerializerOptions != null)
@@ -387,7 +387,7 @@ public CosmosSerializer Serializer
                         $"{nameof(this.Serializer)} is not compatible with {nameof(this.SerializerOptions)}. Only one can be set.  ");
                 }
 
-                this.serializer = value;
+                this.serializerInternal = value;
             }
         }
 
@@ -563,6 +563,14 @@ internal Protocol ConnectionProtocol
         /// </summary>
         internal bool? EnableCpuMonitor { get; set; }
 
+        internal void SetSerializerIfNotConfigured(CosmosSerializer serializer)
+        {
+            if (this.serializerInternal == null)
+            {
+                this.serializerInternal = serializer ?? throw new ArgumentNullException(nameof(serializer));
+            }
+        }
+
         internal CosmosClientOptions Clone()
         {
             CosmosClientOptions cloneConfiguration = (CosmosClientOptions)this.MemberwiseClone();

Microsoft.Azure.Cosmos/src/Resource/ClientContextCore.cs

@@ -115,6 +115,9 @@ internal static CosmosClientContext Create(
                 clientOptions.Serializer,
                 clientOptions.SerializerOptions);
 
+            // This sets the serializer on client options which gives users access to it if a custom one is not configured.
+            clientOptions.SetSerializerIfNotConfigured(serializerCore.GetCustomOrDefaultSerializer());
+
             CosmosResponseFactoryInternal responseFactory = new CosmosResponseFactoryCore(serializerCore);
 
             return new ClientContextCore(

Microsoft.Azure.Cosmos/src/Serializer/CosmosSerializerCore.cs

@@ -91,6 +91,16 @@ internal Stream ToStreamSqlQuerySpec(SqlQuerySpec input, ResourceType resourceTy
             return serializer.ToStream<SqlQuerySpec>(input);
         }
 
+        internal CosmosSerializer GetCustomOrDefaultSerializer()
+        {
+            if (this.customSerializer != null)
+            {
+                return this.customSerializer;
+            }
+
+            return CosmosSerializerCore.propertiesSerializer;
+        }
+
         internal IEnumerable<T> FromFeedResponseStream<T>(
             Stream stream,
             ResourceType resourceType)

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosItemLinqTests.cs

@@ -393,6 +393,9 @@ public async Task ItemLINQWithCamelCaseSerializerOptions(bool isGatewayMode)
                 }
             };
             CosmosClient camelCaseCosmosClient = TestCommon.CreateCosmosClient(builder, false);
+            Assert.IsNotNull(camelCaseCosmosClient.ClientOptions.Serializer);
+            Assert.IsTrue(camelCaseCosmosClient.ClientOptions.Serializer is CosmosJsonSerializerWrapper);
+
             Cosmos.Database database = camelCaseCosmosClient.GetDatabase(this.database.Id);
             Container containerFromCamelCaseClient = database.GetContainer(this.Container.Id);
             IList<ToDoActivity> itemList = await ToDoActivity.CreateRandomItems(container: containerFromCamelCaseClient, pkCount: 2, perPKItemCount: 1, randomPartitionKey: true);

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosJsonSerializerTests.cs

@@ -157,6 +157,7 @@ public async Task TestCustomJsonSerializer()
             CosmosClient mockClient = TestCommon.CreateCosmosClient(
                 (cosmosClientBuilder) => cosmosClientBuilder.WithCustomSerializer(mockJsonSerializer.Object));
             Container mockContainer = mockClient.GetContainer(this.database.Id, this.container.Id);
+            Assert.AreEqual(mockJsonSerializer.Object, mockClient.ClientOptions.Serializer);
 
             //Validate that the custom json serializer is used for creating the item
             ItemResponse<ToDoActivity> response = await mockContainer.CreateItemAsync<ToDoActivity>(item: testItem);

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/Utils/TestCommon.cs

@@ -91,7 +91,9 @@ internal static CosmosClient CreateCosmosClient(Action<CosmosClientBuilder> cust
                 customizeClientBuilder(cosmosClientBuilder);
             }
 
-            return cosmosClientBuilder.Build();
+            CosmosClient client = cosmosClientBuilder.Build();
+            Assert.IsNotNull(client.ClientOptions.Serializer);
+            return client;
         }
 
         internal static CosmosClient CreateCosmosClient(CosmosClientOptions clientOptions, string resourceToken = null)

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/CosmosClientOptionsUnitTests.cs

@@ -71,7 +71,7 @@ public void VerifyCosmosConfigurationPropertiesGetUpdated()
             Assert.IsFalse(clientOptions.AllowBulkExecution);
             Assert.AreEqual(0, clientOptions.CustomHandlers.Count);
             Assert.IsNull(clientOptions.SerializerOptions);
-            Assert.IsNull(clientOptions.Serializer);
+            Assert.IsNotNull(clientOptions.Serializer);
             Assert.IsNull(clientOptions.WebProxy);
             Assert.IsFalse(clientOptions.LimitToEndpoint);
             Assert.IsFalse(clientOptions.EnableTcpConnectionEndpointRediscovery);