Check .Message for null #387

src/OllamaSharp/Chat.cs

@@ -439,17 +439,17 @@ public async IAsyncEnumerable<string> SendAsAsync(ChatRole role, string message,
 		var messageBuilder = new MessageBuilder();
 		await foreach (var answer in Client.ChatAsync(request, cancellationToken).ConfigureAwait(false))
 		{
-			if (answer is null)
+			if (answer?.Message is not { } answerMessageChunk)
 				continue;
 
 			messageBuilder.Append(answer);
 
 			// yield the message content or call the delegate to handle thinking
-			var isThinking = (bool?)Think == true && !string.IsNullOrEmpty(answer.Message.Thinking);
+			var isThinking = (bool?)Think == true && !string.IsNullOrEmpty(answerMessageChunk.Thinking);
 			if (isThinking)
-				OnThink?.Invoke(this, answer.Message.Thinking!);
+				OnThink?.Invoke(this, answerMessageChunk.Thinking!);
 			else
-				yield return answer.Message.Content ?? string.Empty;
+				yield return answerMessageChunk.Content ?? string.Empty;
 		}
 
 		if (messageBuilder.HasValue)

test/ChatTests.cs

@@ -39,6 +39,26 @@ public async Task Sends_Assistant_Answer_To_Streamer()
 			chat.Messages.Last().Content.ShouldBe("Hi human, how are you?");
 		}
 
+		/// <summary>
+		/// Verifies that response chunks without a message are ignored while streaming.
+		/// </summary>
+		[Test]
+		public async Task Ignores_Response_Chunks_Without_Message()
+		{
+			var ollama = new TestOllamaApiClient();
+			ollama.SetExpectedChatResponses(
+				new ChatResponseStream { Message = CreateMessage(ChatRole.Assistant, "Hi ") },
+				new ChatResponseStream { Message = null! },
+				new ChatResponseStream { Message = CreateMessage(ChatRole.Assistant, "human") });
+
+			var chat = new Chat(ollama);
+			var answer = await chat.SendAsync("henlo", CancellationToken.None).StreamToEndAsync();
+
+			answer.ShouldBe("Hi human");
+			chat.Messages.Last().Role.ShouldBe(ChatRole.Assistant);
+			chat.Messages.Last().Content.ShouldBe("Hi human");
+		}
+
 		/// <summary>
 		/// Verifies that a tool call generated by the assistant is streamed and recorded correctly.
 		/// </summary>