feat: ChatClient#mutate adds copies of advisors and advisorParams.

Fixes #3459

- The `mutate()` method adds copies of `advisors` and `advisorParams`.
- Add unit test to validate `mutate()` behavior.

Signed-off-by: YunKui Lu <[email protected]>
(cherry picked from commit f391ff2)

Author: YunKuiLu

spring-ai-client-chat/src/main/java/org/springframework/ai/chat/client/DefaultChatClient.java

@@ -61,6 +61,7 @@
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.MimeType;
 import org.springframework.util.StringUtils;
 
@@ -705,6 +706,7 @@ public TemplateRenderer getTemplateRenderer() {
 		 * Return a {@code ChatClient2Builder} to create a new {@code ChatClient2} whose
 		 * settings are replicated from this {@code ChatClientRequest}.
 		 */
+		@Override
 		public Builder mutate() {
 			DefaultChatClientBuilder builder = (DefaultChatClientBuilder) ChatClient
 				.builder(this.chatModel, this.observationRegistry, this.observationConvention)
@@ -713,6 +715,10 @@ public Builder mutate() {
 				.defaultToolContext(this.toolContext)
 				.defaultToolNames(StringUtils.toStringArray(this.toolNames));
 
+			if (!CollectionUtils.isEmpty(this.advisors)) {
+				builder.defaultAdvisors(a -> a.advisors(this.advisors).params(this.advisorParams));
+			}
+
 			if (StringUtils.hasText(this.userText)) {
 				builder.defaultUser(
 						u -> u.text(this.userText).params(this.userParams).media(this.media.toArray(new Media[0])));

spring-ai-client-chat/src/test/java/org/springframework/ai/chat/client/DefaultChatClientTests.java

@@ -48,6 +48,7 @@
 import org.springframework.ai.content.Media;
 import org.springframework.ai.converter.ListOutputConverter;
 import org.springframework.ai.converter.StructuredOutputConverter;
+import org.springframework.ai.template.TemplateRenderer;
 import org.springframework.ai.tool.ToolCallback;
 import org.springframework.ai.tool.function.FunctionToolCallback;
 import org.springframework.core.ParameterizedTypeReference;
@@ -60,6 +61,7 @@
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 /**
  * Unit tests for {@link DefaultChatClient}.
@@ -124,6 +126,51 @@ void whenPromptWithOptionsThenReturn() {
 		assertThat(spec.getChatOptions()).isEqualTo(chatOptions);
 	}
 
+	@Test
+	void testMutate() {
+		var media = mock(Media.class);
+		var toolCallback = mock(ToolCallback.class);
+		var advisor = mock(Advisor.class);
+		var templateRenderer = mock(TemplateRenderer.class);
+		var chatOptions = mock(ChatOptions.class);
+		var copyChatOptions = mock(ChatOptions.class);
+		when(chatOptions.copy()).thenReturn(copyChatOptions);
+		var toolContext = new HashMap<String, Object>();
+		var userMessage1 = mock(UserMessage.class);
+		var userMessage2 = mock(UserMessage.class);
+
+		DefaultChatClientBuilder defaultChatClientBuilder = new DefaultChatClientBuilder(mock(ChatModel.class));
+		defaultChatClientBuilder.addMessages(List.of(userMessage1, userMessage2));
+		ChatClient originalChatClient = defaultChatClientBuilder.defaultAdvisors(advisor)
+			.defaultOptions(chatOptions)
+			.defaultUser(u -> u.text("original user {userParams}").param("userParams", "user value2").media(media))
+			.defaultSystem(s -> s.text("original system {sysParams}").param("sysParams", "system value1"))
+			.defaultTemplateRenderer(templateRenderer)
+			.defaultToolNames("toolName1", "toolName2")
+			.defaultToolCallbacks(toolCallback)
+			.defaultToolContext(toolContext)
+			.build();
+		var originalSpec = (DefaultChatClient.DefaultChatClientRequestSpec) originalChatClient.prompt();
+
+		ChatClient mutateChatClient = originalChatClient.mutate().build();
+		var mutateSpec = (DefaultChatClient.DefaultChatClientRequestSpec) mutateChatClient.prompt();
+
+		assertThat(mutateSpec).isNotSameAs(originalSpec);
+
+		assertThat(mutateSpec.getMessages()).hasSize(2).containsOnly(userMessage1, userMessage2);
+		assertThat(mutateSpec.getAdvisors()).hasSize(1).containsOnly(advisor);
+		assertThat(mutateSpec.getChatOptions()).isEqualTo(copyChatOptions);
+		assertThat(mutateSpec.getUserText()).isEqualTo("original user {userParams}");
+		assertThat(mutateSpec.getUserParams()).containsEntry("userParams", "user value2");
+		assertThat(mutateSpec.getMedia()).hasSize(1).containsOnly(media);
+		assertThat(mutateSpec.getSystemText()).isEqualTo("original system {sysParams}");
+		assertThat(mutateSpec.getSystemParams()).containsEntry("sysParams", "system value1");
+		assertThat(mutateSpec.getTemplateRenderer()).isEqualTo(templateRenderer);
+		assertThat(mutateSpec.getToolNames()).containsExactly("toolName1", "toolName2");
+		assertThat(mutateSpec.getToolCallbacks()).containsExactly(toolCallback);
+		assertThat(mutateSpec.getToolContext()).isEqualTo(toolContext);
+	}
+
 	@Test
 	void whenMutateChatClientRequest() {
 		ChatClient chatClient = new DefaultChatClientBuilder(mock(ChatModel.class)).build();