extract onFinishReason() method

spring-ai-core/src/main/java/org/springframework/ai/chat/client/advisor/QuestionAnswerAdvisor.java

@@ -19,19 +19,13 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import org.springframework.ai.chat.client.advisor.api.*;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Schedulers;
 
-import org.springframework.ai.chat.client.advisor.api.AdvisedRequest;
-import org.springframework.ai.chat.client.advisor.api.AdvisedResponse;
-import org.springframework.ai.chat.client.advisor.api.CallAroundAdvisor;
-import org.springframework.ai.chat.client.advisor.api.CallAroundAdvisorChain;
-import org.springframework.ai.chat.client.advisor.api.StreamAroundAdvisor;
-import org.springframework.ai.chat.client.advisor.api.StreamAroundAdvisorChain;
 import org.springframework.ai.chat.model.ChatResponse;
 import org.springframework.ai.chat.prompt.PromptTemplate;
 import org.springframework.ai.document.Document;
@@ -201,7 +195,7 @@ public Flux<AdvisedResponse> aroundStream(AdvisedRequest advisedRequest, StreamA
 		// @formatter:on
 
 		return advisedResponses.map(ar -> {
-			if (onFinishReason().test(ar)) {
+			if (AdvisedResponseStreamUtils.onFinishReason().test(ar)) {
 				ar = after(ar);
 			}
 			return ar;
@@ -260,16 +254,6 @@ protected Filter.Expression doGetFilterExpression(Map<String, Object> context) {
 
 	}
 
-	private Predicate<AdvisedResponse> onFinishReason() {
-		return advisedResponse -> advisedResponse.response()
-			.getResults()
-			.stream()
-			.filter(result -> result != null && result.getMetadata() != null
-					&& StringUtils.hasText(result.getMetadata().getFinishReason()))
-			.findFirst()
-			.isPresent();
-	}
-
 	public static final class Builder {
 
 		private final VectorStore vectorStore;

spring-ai-core/src/main/java/org/springframework/ai/chat/client/advisor/api/AdvisedResponseStreamUtils.java

@@ -0,0 +1,31 @@
+package org.springframework.ai.chat.client.advisor.api;
+
+import org.springframework.ai.chat.model.ChatResponse;
+import org.springframework.util.StringUtils;
+
+import java.util.function.Predicate;
+
+/**
+ * A stream utility class to provide support methods handling {@link AdvisedResponse}.
+ */
+public final class AdvisedResponseStreamUtils {
+
+	/**
+	 * Returns a predicate that checks whether the provided {@link AdvisedResponse}
+	 * contains a {@link ChatResponse} with at least one result having a non-empty finish
+	 * reason in its metadata.
+	 * @return a {@link Predicate} that evaluates whether the finish reason exists within
+	 * the response metadata.
+	 */
+	public static Predicate<AdvisedResponse> onFinishReason() {
+		return advisedResponse -> {
+			ChatResponse chatResponse = advisedResponse.response();
+			return chatResponse != null && chatResponse.getResults() != null
+					&& chatResponse.getResults()
+						.stream()
+						.anyMatch(result -> result != null && result.getMetadata() != null
+								&& StringUtils.hasText(result.getMetadata().getFinishReason()));
+		};
+	}
+
+}

spring-ai-core/src/main/java/org/springframework/ai/chat/client/advisor/api/BaseAdvisor.java

@@ -16,16 +16,12 @@
 
 package org.springframework.ai.chat.client.advisor.api;
 
-import java.util.function.Predicate;
-
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
 
-import org.springframework.ai.chat.model.ChatResponse;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 
 /**
  * Base advisor that implements common aspects of the {@link CallAroundAdvisor} and
@@ -65,24 +61,13 @@ default Flux<AdvisedResponse> aroundStream(AdvisedRequest advisedRequest, Stream
 			.flatMapMany(chain::nextAroundStream);
 
 		return advisedResponses.map(ar -> {
-			if (onFinishReason().test(ar)) {
+			if (AdvisedResponseStreamUtils.onFinishReason().test(ar)) {
 				ar = after(ar);
 			}
 			return ar;
 		}).onErrorResume(error -> Flux.error(new IllegalStateException("Stream processing failed", error)));
 	}
 
-	private Predicate<AdvisedResponse> onFinishReason() {
-		return advisedResponse -> {
-			ChatResponse chatResponse = advisedResponse.response();
-			return chatResponse != null && chatResponse.getResults() != null
-					&& chatResponse.getResults()
-						.stream()
-						.anyMatch(result -> result != null && result.getMetadata() != null
-								&& StringUtils.hasText(result.getMetadata().getFinishReason()));
-		};
-	}
-
 	@Override
 	default String getName() {
 		return this.getClass().getSimpleName();

spring-ai-core/src/test/java/org/springframework/ai/chat/client/advisor/api/AdvisedResponseStreamUtilsTest.java

@@ -0,0 +1,82 @@
+package org.springframework.ai.chat.client.advisor.api;
+
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.springframework.ai.chat.messages.AssistantMessage;
+import org.springframework.ai.chat.metadata.ChatGenerationMetadata;
+import org.springframework.ai.chat.model.ChatResponse;
+import org.springframework.ai.chat.model.Generation;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Unit tests for {@link AdvisedResponseStreamUtils}.
+ *
+ * @author ghdcksgml1
+ */
+class AdvisedResponseStreamUtilsTest {
+
+	@Nested
+	class OnFinishReason {
+
+		@Test
+		void whenChatResponseIsNullThenReturnFalse() {
+			AdvisedResponse response = mock(AdvisedResponse.class);
+			given(response.response()).willReturn(null);
+
+			boolean result = AdvisedResponseStreamUtils.onFinishReason().test(response);
+
+			assertFalse(result);
+		}
+
+		@Test
+		void whenChatResponseResultsIsNullThenReturnFalse() {
+			AdvisedResponse response = mock(AdvisedResponse.class);
+			ChatResponse chatResponse = mock(ChatResponse.class);
+
+			given(chatResponse.getResults()).willReturn(null);
+			given(response.response()).willReturn(chatResponse);
+
+			boolean result = AdvisedResponseStreamUtils.onFinishReason().test(response);
+
+			assertFalse(result);
+		}
+
+		@Test
+		void whenChatIsRunningThenReturnFalse() {
+			AdvisedResponse response = mock(AdvisedResponse.class);
+			ChatResponse chatResponse = mock(ChatResponse.class);
+
+			Generation generation = new Generation(new AssistantMessage("running.."), ChatGenerationMetadata.NULL);
+
+			given(chatResponse.getResults()).willReturn(List.of(generation));
+			given(response.response()).willReturn(chatResponse);
+
+			boolean result = AdvisedResponseStreamUtils.onFinishReason().test(response);
+
+			assertFalse(result);
+		}
+
+		@Test
+		void whenChatIsStopThenReturnTrue() {
+			AdvisedResponse response = mock(AdvisedResponse.class);
+			ChatResponse chatResponse = mock(ChatResponse.class);
+
+			Generation generation = new Generation(new AssistantMessage("finish."),
+					ChatGenerationMetadata.builder().finishReason("STOP").build());
+
+			given(chatResponse.getResults()).willReturn(List.of(generation));
+			given(response.response()).willReturn(chatResponse);
+
+			boolean result = AdvisedResponseStreamUtils.onFinishReason().test(response);
+
+			assertTrue(result);
+		}
+
+	}
+
+}