GH-5007: Fix handling when response contains both text and function calls

Signed-off-by: Nathan Grand <nathangrand@quantexa.com>

Author: q-nathangrand

models/spring-ai-google-genai/src/main/java/org/springframework/ai/google/genai/GoogleGenAiChatModel.java

@@ -22,6 +22,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
@@ -647,45 +648,30 @@ protected List<Generation> responseCandidateToGeneration(Candidate candidate) {
 			.finishReason(candidateFinishReason.toString())
 			.build();
 
-		boolean isFunctionCall = candidate.content().isPresent() && candidate.content().get().parts().isPresent()
-				&& candidate.content().get().parts().get().stream().allMatch(part -> part.functionCall().isPresent());
+		List<Part> parts = candidate.content().get().parts().orElse(List.of());
 
-		if (isFunctionCall) {
-			List<AssistantMessage.ToolCall> assistantToolCalls = candidate.content()
-				.get()
-				.parts()
-				.orElse(List.of())
-				.stream()
-				.filter(part -> part.functionCall().isPresent())
-				.map(part -> {
-					FunctionCall functionCall = part.functionCall().get();
-					var functionName = functionCall.name().orElse("");
-					String functionArguments = mapToJson(functionCall.args().orElse(Map.of()));
-					return new AssistantMessage.ToolCall("", "function", functionName, functionArguments);
-				})
-				.toList();
+		List<AssistantMessage.ToolCall> assistantToolCalls = parts.stream()
+			.filter(part -> part.functionCall().isPresent())
+			.map(part -> {
+				FunctionCall functionCall = part.functionCall().get();
+				var functionName = functionCall.name().orElse("");
+				String functionArguments = mapToJson(functionCall.args().orElse(Map.of()));
+				return new AssistantMessage.ToolCall("", "function", functionName, functionArguments);
+			})
+			.toList();
 
-			AssistantMessage assistantMessage = AssistantMessage.builder()
-				.content("")
-				.properties(messageMetadata)
-				.toolCalls(assistantToolCalls)
-				.build();
+		String text = parts.stream()
+			.filter(part -> part.text().isPresent() && !part.text().get().isEmpty())
+			.map(part -> part.text().get())
+			.collect(Collectors.joining(" "));
 
-			return List.of(new Generation(assistantMessage, chatGenerationMetadata));
-		}
-		else {
-			return candidate.content()
-				.get()
-				.parts()
-				.orElse(List.of())
-				.stream()
-				.map(part -> AssistantMessage.builder()
-					.content(part.text().orElse(""))
-					.properties(messageMetadata)
-					.build())
-				.map(assistantMessage -> new Generation(assistantMessage, chatGenerationMetadata))
-				.toList();
-		}
+		AssistantMessage assistantMessage = AssistantMessage.builder()
+			.content(text)
+			.properties(messageMetadata)
+			.toolCalls(assistantToolCalls)
+			.build();
+
+		return List.of(new Generation(assistantMessage, chatGenerationMetadata));
 	}
 
 	private ChatResponseMetadata toChatResponseMetadata(Usage usage, String modelVersion) {

models/spring-ai-google-genai/src/test/java/org/springframework/ai/google/genai/GoogleGenAiChatModelIT.java

@@ -388,6 +388,41 @@ void jsonTextToolCallingTest() {
 		assertThat(response).contains("2025-05-08T10:10:10+02:00");
 	}
 
+	/**
+	 * See https://github.com/spring-projects/spring-ai/pull/4599
+	 */
+	@Test
+	void testMixedPartsMessages() {
+
+		ToolCallingManager toolCallingManager = ToolCallingManager.builder()
+			.observationRegistry(ObservationRegistry.NOOP)
+			.build();
+
+		GoogleGenAiChatModel chatModelWithTools = GoogleGenAiChatModel.builder()
+			.genAiClient(genAiClient())
+			.toolCallingManager(toolCallingManager)
+			.defaultOptions(GoogleGenAiChatOptions.builder()
+				.model(GoogleGenAiChatModel.ChatModel.GEMINI_2_5_FLASH)
+				.temperature(0.0)
+				.build())
+			.build();
+
+		ChatClient chatClient = ChatClient.builder(chatModelWithTools).build();
+
+		// Create a prompt that will encourage gemini to explain why it is calling tools
+		// as it does.
+		AlarmTools alarmTools = new AlarmTools();
+		String response = chatClient.prompt()
+			.tools(new CurrentTimeTools(), alarmTools)
+			.system("You MUST include reasoning when you issue tool calls.")
+			.user("Set an alarm for an hour from now, and tell me what time that was for.")
+			.call()
+			.content();
+
+		assertThat(response).isEqualTo("I have set an alarm for 11:10 AM.");
+		assertThat(alarmTools.getAlarm()).isEqualTo("2025-05-08T11:10:10+02:00");
+	}
+
 	@Test
 	void testThinkingBudgetGeminiProAutomaticDecisionByModel() {
 		GoogleGenAiChatModel chatModelWithThinkingBudget = GoogleGenAiChatModel.builder()
@@ -516,6 +551,21 @@ String getCurrentDateTime() {
 
 	}
 
+	public static class AlarmTools {
+
+		private String alarm;
+
+		@Tool(description = "Set a user alarm for the given time, provided in ISO-8601 format")
+		void setAlarm(String time) {
+			this.alarm = time;
+		}
+
+		public String getAlarm() {
+			return this.alarm;
+		}
+
+	}
+
 	record ActorsFilmsRecord(String actor, List<String> movies) {
 
 	}

models/spring-ai-google-genai/src/test/java/org/springframework/ai/google/genai/cache/GoogleGenAiCachedContentServiceTests.java

@@ -152,7 +152,7 @@ void testUpdateCachedContent() {
 		assertThat(updated.getName()).isEqualTo(name);
 		assertThat(updated.getTtl()).isEqualTo(newTtl);
 		assertThat(updated.getUpdateTime()).isNotNull();
-		assertThat(updated.getUpdateTime()).isAfter(created.getCreateTime());
+		assertThat(updated.getUpdateTime()).isAfterOrEqualTo(created.getCreateTime());
 	}
 
 	@Test