From 6e1d40d33936d2f98b1d2341254d367c5253d5f4 Mon Sep 17 00:00:00 2001
From: Nalu Tripician <27316859+NaluTripician@users.noreply.github.com>
Date: Mon, 15 Jul 2024 13:40:20 -0700
Subject: [PATCH] ChangeFeed: Adds MalformedContinuationToken SubstatusCode to
 exception (#4583)

---
 .../Query/Core/ExceptionToCosmosException.cs    |  5 ++++-
 .../CosmosItemTests.cs                          | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Microsoft.Azure.Cosmos/src/Query/Core/ExceptionToCosmosException.cs b/Microsoft.Azure.Cosmos/src/Query/Core/ExceptionToCosmosException.cs
index 02c1882e26..5ee4eca609 100644
--- a/Microsoft.Azure.Cosmos/src/Query/Core/ExceptionToCosmosException.cs
+++ b/Microsoft.Azure.Cosmos/src/Query/Core/ExceptionToCosmosException.cs
@@ -157,7 +157,10 @@ internal override CosmosException Visit(
             {
                 return CosmosExceptionFactory.CreateBadRequestException(
                     message: malformedChangeFeedContinuationTokenException.Message,
-                    headers: new Headers(),
+                    headers: new Headers()
+                    {
+                        SubStatusCode = Documents.SubStatusCodes.MalformedContinuationToken
+                    },
                     stackTrace: malformedChangeFeedContinuationTokenException.StackTrace,
                     innerException: malformedChangeFeedContinuationTokenException,
                     trace: trace);
diff --git a/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosItemTests.cs b/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosItemTests.cs
index 0ad71e7085..25b46d670f 100644
--- a/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosItemTests.cs
+++ b/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosItemTests.cs
@@ -3319,6 +3319,23 @@ await CosmosItemTests.GivenItemAsyncWhenMissingMemberHandlingIsErrorThenExpectsC
                     id: itemIdThatWillNotExist,
                     partitionKey: new Cosmos.PartitionKey(partitionKeyValue),
                     cancellationToken: cancellationToken));
+        }
+
+        [TestMethod]
+        public async Task MalformedChangeFeedContinuationTokenSubStatusCodeTest()
+        {
+            FeedIterator badIterator = this.Container.GetChangeFeedStreamIterator(
+                    ChangeFeedStartFrom.ContinuationToken("AMalformedContinuationToken"),
+                    ChangeFeedMode.Incremental,
+                    new ChangeFeedRequestOptions()
+                    {
+                        PageSizeHint = 100
+                    });
+
+            ResponseMessage response = await badIterator.ReadNextAsync();
+
+            Assert.AreEqual(HttpStatusCode.BadRequest, response.StatusCode);
+            Assert.AreEqual(SubStatusCodes.MalformedContinuationToken, response.Headers.SubStatusCode);
         }
 
         private static async Task GivenItemStreamAsyncWhenMissingMemberHandlingIsErrorThenExpectsCosmosExceptionTestAsync(