Fix handling of streaming update of unexpected type (Azure#52437)

nick863 · web-flow · commit 3f0d04e62fb3 · 2025-09-03T15:18:53.000-07:00
diff --git a/sdk/ai/Azure.AI.Agents.Persistent/CHANGELOG.md b/sdk/ai/Azure.AI.Agents.Persistent/CHANGELOG.md
@@ -11,6 +11,7 @@
 ### Breaking Changes
 
 ### Bugs Fixed
+- Fix handling of streaming update of unexpected type [issue](https://github.com/Azure/azure-sdk-for-net/issues/52407).
 
 ### Other Changes
 
diff --git a/sdk/ai/Azure.AI.Agents.Persistent/src/Custom/Streaming/AsyncStreamingUpdateCollection.cs b/sdk/ai/Azure.AI.Agents.Persistent/src/Custom/Streaming/AsyncStreamingUpdateCollection.cs
@@ -212,8 +212,13 @@ async ValueTask<bool> IAsyncEnumerator<StreamingUpdate>.MoveNextAsync()
 	                    return false;
 	                }
 
-	                var updates = StreamingUpdate.FromEvent(_events.Current);
-	                _updates = updates.GetEnumerator();
+	                IEnumerable<StreamingUpdate> updates = StreamingUpdate.FromEvent(_events.Current);
+                    if (updates is null)
+                    {
+                        StreamingUpdateReason updateKind = StreamingUpdateReasonExtensions.FromSseEventLabel(_events.Current.EventType);
+                        throw new InvalidOperationException($"Unknown streaming update reason {updateKind}");
+                    }
+                    _updates = updates.GetEnumerator();
 
 	                if (_updates.MoveNext())
 	                {
diff --git a/sdk/ai/Azure.AI.Agents.Persistent/src/Custom/Streaming/StreamingUpdateCollection.cs b/sdk/ai/Azure.AI.Agents.Persistent/src/Custom/Streaming/StreamingUpdateCollection.cs
@@ -204,7 +204,12 @@ public bool MoveNext()
                         return false;
                     }
 
-                    var updates = StreamingUpdate.FromEvent(_events.Current);
+                    IEnumerable<StreamingUpdate> updates = StreamingUpdate.FromEvent(_events.Current);
+                    if (updates is null)
+                    {
+                        StreamingUpdateReason updateKind = StreamingUpdateReasonExtensions.FromSseEventLabel(_events.Current.EventType);
+                        throw new InvalidOperationException($"Unknown streaming update reason {updateKind}");
+                    }
                     _updates = updates.GetEnumerator();
 
                     if (_updates.MoveNext())

Original file line number	Diff line number	Diff line change
`@@ -212,8 +212,13 @@ async ValueTask<bool> IAsyncEnumerator<StreamingUpdate>.MoveNextAsync()`
`212`	`212`	`return false;`
`213`	`213`	`}`
`214`	`214`
`215`		`- var updates = StreamingUpdate.FromEvent(_events.Current);`
`216`		`- _updates = updates.GetEnumerator();`
	`215`	`+ IEnumerable<StreamingUpdate> updates = StreamingUpdate.FromEvent(_events.Current);`
	`216`	`+ if (updates is null)`
	`217`	`+ {`
	`218`	`+ StreamingUpdateReason updateKind = StreamingUpdateReasonExtensions.FromSseEventLabel(_events.Current.EventType);`
	`219`	`+ throw new InvalidOperationException($"Unknown streaming update reason {updateKind}");`
	`220`	`+ }`
	`221`	`+ _updates = updates.GetEnumerator();`
`217`	`222`
`218`	`223`	`if (_updates.MoveNext())`
`219`	`224`	`{`