HttpClient: Fixes HttpResponseMessage.RequestMessage is null in WASM

Microsoft.Azure.Cosmos/src/HttpClient/CosmosHttpClientCore.cs

@@ -228,6 +228,12 @@ public override Task<HttpResponseMessage> SendHttpAsync(
                                 HttpCompletionOption.ResponseHeadersRead,
                                 cancellationToken);
 
+                        // WebAssembly HttpClient does not set the RequestMessage property on SendAsync
+                        if (responseMessage.RequestMessage == null)
+                        {
+                            responseMessage.RequestMessage = requestMessage;
+                        }
+
                         DateTime receivedTimeUtc = DateTime.UtcNow;
                         TimeSpan durationTimeSpan = receivedTimeUtc - sendTimeUtc;
 

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

@@ -0,0 +1,56 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos.Tests
+{
+    using System.Threading.Tasks;
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+    using Microsoft.Azure.Documents;
+    using System;
+    using System.Net.Http;
+    using System.Net;
+    using System.Threading;
+
+    [TestClass]
+    public class CosmosHttpClientCoreTests
+    {
+        [TestMethod]
+        public async Task ResponseMessageHasRequestMessageAsync()
+        {
+            // We don't set the RequestMessage property on purpose on the Failed response
+            // This will make it go through GatewayStoreClient.CreateDocumentClientExceptionAsync
+            Func<HttpRequestMessage, Task<HttpResponseMessage>> sendFunc = request =>
+            {
+                HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.NotFound)
+                {
+                    Content = new StringContent("test")
+                };
+                return Task.FromResult(response);
+            };
+
+            DocumentClientEventSource eventSource = DocumentClientEventSource.Instance;
+            HttpMessageHandler messageHandler = new MockMessageHandler(sendFunc);
+            CosmosHttpClient cosmoshttpClient = MockCosmosUtil.CreateCosmosHttpClient(() => new HttpClient(messageHandler));
+
+            HttpRequestMessage httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, new Uri("http://localhost"));
+
+            HttpResponseMessage responseMessage = await cosmoshttpClient.SendHttpAsync(() => new ValueTask<HttpRequestMessage>(httpRequestMessage), ResourceType.Collection, null, default);
+
+            Assert.AreEqual(httpRequestMessage, responseMessage.RequestMessage);
+        }
+
+        private class MockMessageHandler : HttpMessageHandler
+        {
+            private readonly Func<HttpRequestMessage, Task<HttpResponseMessage>> sendFunc;
+            public MockMessageHandler(Func<HttpRequestMessage, Task<HttpResponseMessage>> func)
+            {
+                this.sendFunc = func;
+            }
+            protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+            {
+                return await this.sendFunc(request);
+            }
+        }
+    }
+}