Mistral AI streaming function API change fix

Author: tzolov

models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatClient.java

@@ -285,7 +285,13 @@ protected List<ChatCompletionMessage> doGetUserMessages(ChatCompletionRequest re
 	@SuppressWarnings("null")
 	@Override
 	protected ChatCompletionMessage doGetToolResponseMessage(ResponseEntity<ChatCompletion> chatCompletion) {
-		return chatCompletion.getBody().choices().iterator().next().message();
+		ChatCompletionMessage msg = chatCompletion.getBody().choices().iterator().next().message();
+		if (msg.role() == null) {
+			// add missing role
+			msg = new ChatCompletionMessage(msg.content(), ChatCompletionMessage.Role.ASSISTANT, msg.name(),
+					msg.toolCalls());
+		}
+		return msg;
 	}
 
 	@Override

models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/api/MistralAiApi.java

@@ -535,14 +535,12 @@ public enum ChatCompletionFinishReason {
 		  */
 		 @JsonProperty("model_length") MODEL_LENGTH,
 		 /**
-		  * The model called a tool.
+		  *
 		  */
-		 @JsonProperty("tool_call") TOOL_CALL,
-
-		 // anticipation of future changes. Based on:
-		 // https://github.com/mistralai/client-python/blob/main/src/mistralai/models/chat_completion.py
 		 @JsonProperty("error") ERROR,
-
+		 /**
+		  * The model requested a tool call.
+		  */
 		 @JsonProperty("tool_calls") TOOL_CALLS
 		 // @formatter:on
 

models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/api/MistralAiStreamFunctionCallingHelper.java

@@ -190,8 +190,7 @@ public boolean isStreamingToolFunctionCallFinish(ChatCompletionChunk chatComplet
 		}
 
 		var choice = choices.get(0);
-		return choice.finishReason() == ChatCompletionFinishReason.TOOL_CALL
-				|| choice.finishReason() == ChatCompletionFinishReason.TOOL_CALLS;
+		return choice.finishReason() == ChatCompletionFinishReason.TOOL_CALLS;
 	}
 
 }