Address empty text chunck problem (#6723)

rogerbarreto · web-flow · commit 2130f3676f28 · 2025-08-15T11:25:51.000-04:00
diff --git a/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIAssistantsChatClient.cs b/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIAssistantsChatClient.cs
@@ -245,6 +245,12 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
 
                         if (fileId is not null)
                         {
+                            if (textUpdate.Contents.Count == 0)
+                            {
+                                // In case a chunk doesn't have text content, create one with empty text to hold the annotation.
+                                textUpdate.Contents.Add(new TextContent(string.Empty));
+                            }
+
                             (((TextContent)textUpdate.Contents[0]).Annotations ??= []).Add(new CitationAnnotation
                             {
                                 RawRepresentation = tau,

Original file line number	Diff line number	Diff line change
`@@ -245,6 +245,12 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(`
`245`	`245`
`246`	`246`	`if (fileId is not null)`
`247`	`247`	`{`
	`248`	`+ if (textUpdate.Contents.Count == 0)`
	`249`	`+ {`
	`250`	`+ // In case a chunk doesn't have text content, create one with empty text to hold the annotation.`
	`251`	`+ textUpdate.Contents.Add(new TextContent(string.Empty));`
	`252`	`+ }`
	`253`	`+`
`248`	`254`	`(((TextContent)textUpdate.Contents[0]).Annotations ??= []).Add(new CitationAnnotation`
`249`	`255`	`{`
`250`	`256`	`RawRepresentation = tau,`