Request Options : Adds fix to support injecting/appending custom head…

…ers into request via RequestOptions. (Azure#2371)

This PR focuses on adding support to inject custom headers into requests via RequestOptions. This would allow customers to directly inject custom headers. (The RequestOptions.Properties is meant for the client context and is not meant for adding headers.)

Microsoft.Azure.Cosmos/src/RequestOptions/RequestOptions.cs

@@ -36,6 +36,16 @@ public class RequestOptions
         /// </summary>
         public IReadOnlyDictionary<string, object> Properties { get; set; }
 
+#if PREVIEW
+        /// <summary>
+        /// Gets or sets a delegate which injects/appends a custom header in the request.
+        /// </summary>
+        public 
+#else
+        internal        
+#endif
+        Action<Headers> AddRequestHeaders { get; set; }
+
         /// <summary>
         /// Gets or sets the boolean to use effective partition key routing in the cosmos db request.
         /// </summary>
@@ -79,6 +89,22 @@ internal virtual void PopulateRequestOptions(RequestMessage request)
             {
                 request.Headers.Add(HttpConstants.HttpHeaders.IfNoneMatch, this.IfNoneMatchEtag);
             }
+
+            this.AddRequestHeaders?.Invoke(request.Headers);
+        }
+
+#if PREVIEW
+        /// <summary>
+        /// Clone RequestOptions.
+        /// </summary>
+        /// <returns> cloned RequestOptions. </returns>
+        public
+#else
+        internal
+#endif
+        RequestOptions ShallowCopy()
+        {
+            return this.MemberwiseClone() as RequestOptions;
         }
 
         /// <summary>

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

@@ -46,6 +46,41 @@ public async Task VerifyKnownHeaders()
             }
         }
 
+        [TestMethod]
+        public async Task VerifyRequestOptionCustomRequestHeaders()
+        {
+            CustomHeaderValidationHandler headerValidationHandler = new CustomHeaderValidationHandler();
+            using CosmosClient client = TestCommon.CreateCosmosClient(x => x.AddCustomHandlers(headerValidationHandler));
+            Database database = null;
+            try
+            {
+                database = await client.CreateDatabaseAsync(nameof(VerifyRequestOptionCustomRequestHeaders) + Guid.NewGuid().ToString());
+                Container container = await database.CreateContainerAsync(
+                Guid.NewGuid().ToString(),
+                "/pk");
+
+                ToDoActivity toDoActivity = ToDoActivity.CreateRandomToDoActivity();
+                ItemRequestOptions requestOptions = new ItemRequestOptions
+                {
+                    AddRequestHeaders = (headers) => headers["x-ms-cosmos-database-rid"] = "databaseRidValue",
+                };
+
+                await container.CreateItemAsync(toDoActivity, new PartitionKey(toDoActivity.pk), requestOptions: requestOptions);
+
+                // null pass
+                requestOptions.AddRequestHeaders = null;
+
+                await container.ReadItemAsync<ToDoActivity>(toDoActivity.id, new PartitionKey(toDoActivity.pk), requestOptions: requestOptions);
+            }
+            finally
+            {
+                if (database != null)
+                {
+                    await database.DeleteStreamAsync();
+                }
+            }
+        }
+
         private class HeaderValidationHandler : RequestHandler
         {
             public override async Task<ResponseMessage> SendAsync(RequestMessage request, CancellationToken cancellationToken)
@@ -76,5 +111,28 @@ private void ValidateLazyHeadersAreNotCreated(CosmosMessageHeadersInternal inter
                 }
             }
         }
+
+        private class CustomHeaderValidationHandler : RequestHandler
+        {
+            public override async Task<ResponseMessage> SendAsync(RequestMessage request, CancellationToken cancellationToken)
+            {
+                if (request.ResourceType == Documents.ResourceType.Document)
+                {
+                    this.ValidateCustomHeaders(request.Headers.CosmosMessageHeaders);
+                }
+
+                return await base.SendAsync(request, cancellationToken);
+            }
+
+            private void ValidateCustomHeaders(CosmosMessageHeadersInternal internalHeaders)
+            {
+                string customHeaderValue = internalHeaders.Get("x-ms-cosmos-database-rid");
+
+                if (!string.IsNullOrEmpty(customHeaderValue))
+                {
+                    Assert.AreEqual("databaseRidValue", customHeaderValue);
+                }                
+            }
+        }
     }
 }

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Contracts/DotNetPreviewSDKAPI.json

@@ -1797,7 +1797,32 @@
           "NestedTypes": {}
         }
       },
-      "Members": {},
+      "Members": {
+        "Microsoft.Azure.Cosmos.RequestOptions ShallowCopy()": {
+          "Type": "Method",
+          "Attributes": [],
+          "MethodInfo": "Microsoft.Azure.Cosmos.RequestOptions ShallowCopy();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+        },
+        "System.Action`1[Microsoft.Azure.Cosmos.Headers] AddRequestHeaders": {
+          "Type": "Property",
+          "Attributes": [],
+          "MethodInfo": "System.Action`1[Microsoft.Azure.Cosmos.Headers] AddRequestHeaders;CanRead:True;CanWrite:True;System.Action`1[Microsoft.Azure.Cosmos.Headers] get_AddRequestHeaders();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;Void set_AddRequestHeaders(System.Action`1[Microsoft.Azure.Cosmos.Headers]);IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+        },
+        "System.Action`1[Microsoft.Azure.Cosmos.Headers] get_AddRequestHeaders()[System.Runtime.CompilerServices.CompilerGeneratedAttribute()]": {
+          "Type": "Method",
+          "Attributes": [
+            "CompilerGeneratedAttribute"
+          ],
+          "MethodInfo": "System.Action`1[Microsoft.Azure.Cosmos.Headers] get_AddRequestHeaders();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+        },
+        "Void set_AddRequestHeaders(System.Action`1[Microsoft.Azure.Cosmos.Headers])[System.Runtime.CompilerServices.CompilerGeneratedAttribute()]": {
+          "Type": "Method",
+          "Attributes": [
+            "CompilerGeneratedAttribute"
+          ],
+          "MethodInfo": "Void set_AddRequestHeaders(System.Action`1[Microsoft.Azure.Cosmos.Headers]);IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+        }
+      },
       "NestedTypes": {}
     },
     "Microsoft.Azure.Cosmos.TransactionalBatch;System.Object;IsAbstract:True;IsSealed:False;IsInterface:False;IsEnum:False;IsClass:True;IsValueType:False;IsNested:False;IsGenericType:False;IsSerializable:False": {