refactor: BaseAgent: Unwrap List from Optional, improve test coverage

PiperOrigin-RevId: 860210309

Author: google-genai-bot

core/src/main/java/com/google/adk/agents/BaseAgent.java

@@ -59,8 +59,8 @@ public abstract class BaseAgent {
 
   private final List<? extends BaseAgent> subAgents;
 
-  private final Optional<List<? extends BeforeAgentCallback>> beforeAgentCallback;
-  private final Optional<List<? extends AfterAgentCallback>> afterAgentCallback;
+  private final List<? extends BeforeAgentCallback> beforeAgentCallback;
+  private final List<? extends AfterAgentCallback> afterAgentCallback;
 
   /**
    * Creates a new BaseAgent.
@@ -83,8 +83,9 @@ public BaseAgent(
     this.description = description;
     this.parentAgent = null;
     this.subAgents = subAgents != null ? subAgents : ImmutableList.of();
-    this.beforeAgentCallback = Optional.ofNullable(beforeAgentCallback);
-    this.afterAgentCallback = Optional.ofNullable(afterAgentCallback);
+    this.beforeAgentCallback =
+        beforeAgentCallback != null ? beforeAgentCallback : ImmutableList.of();
+    this.afterAgentCallback = afterAgentCallback != null ? afterAgentCallback : ImmutableList.of();
 
     // Establish parent relationships for all sub-agents if needed.
     for (BaseAgent subAgent : this.subAgents) {
@@ -171,11 +172,11 @@ public List<? extends BaseAgent> subAgents() {
     return subAgents;
   }
 
-  public Optional<List<? extends BeforeAgentCallback>> beforeAgentCallback() {
+  public List<? extends BeforeAgentCallback> beforeAgentCallback() {
     return beforeAgentCallback;
   }
 
-  public Optional<List<? extends AfterAgentCallback>> afterAgentCallback() {
+  public List<? extends AfterAgentCallback> afterAgentCallback() {
     return afterAgentCallback;
   }
 
@@ -185,7 +186,7 @@ public Optional<List<? extends AfterAgentCallback>> afterAgentCallback() {
    * <p>This method is only for use by Agent Development Kit.
    */
   public List<? extends BeforeAgentCallback> canonicalBeforeAgentCallbacks() {
-    return beforeAgentCallback.orElse(ImmutableList.of());
+    return beforeAgentCallback;
   }
 
   /**
@@ -194,7 +195,7 @@ public List<? extends BeforeAgentCallback> canonicalBeforeAgentCallbacks() {
    * <p>This method is only for use by Agent Development Kit.
    */
   public List<? extends AfterAgentCallback> canonicalAfterAgentCallbacks() {
-    return afterAgentCallback.orElse(ImmutableList.of());
+    return afterAgentCallback;
   }
 
   /**
@@ -239,8 +240,7 @@ public Flowable<Event> runAsync(InvocationContext parentContext) {
               () ->
                   callCallback(
                           beforeCallbacksToFunctions(
-                              invocationContext.pluginManager(),
-                              beforeAgentCallback.orElse(ImmutableList.of())),
+                              invocationContext.pluginManager(), beforeAgentCallback),
                           invocationContext)
                       .flatMapPublisher(
                           beforeEventOpt -> {
@@ -257,7 +257,7 @@ public Flowable<Event> runAsync(InvocationContext parentContext) {
                                         callCallback(
                                                 afterCallbacksToFunctions(
                                                     invocationContext.pluginManager(),
-                                                    afterAgentCallback.orElse(ImmutableList.of())),
+                                                    afterAgentCallback),
                                                 invocationContext)
                                             .flatMapPublisher(Flowable::fromOptional));
 

core/src/test/java/com/google/adk/agents/BaseAgentTest.java

@@ -316,4 +316,24 @@ public void canonicalCallbacks_returnsListWhenPresent() {
     assertThat(agent.canonicalBeforeAgentCallbacks()).containsExactly(bc);
     assertThat(agent.canonicalAfterAgentCallbacks()).containsExactly(ac);
   }
+
+  @Test
+  public void runLive_invokesRunLiveImpl() {
+    var runLiveImpl = TestCallback.<Void>returningEmpty();
+    Content runLiveImplContent = Content.fromParts(Part.fromText("live_output"));
+    TestBaseAgent agent =
+        new TestBaseAgent(
+            TEST_AGENT_NAME,
+            TEST_AGENT_DESCRIPTION,
+            /* beforeAgentCallbacks= */ ImmutableList.of(),
+            /* afterAgentCallbacks= */ ImmutableList.of(),
+            runLiveImpl.asRunLiveImplSupplier(runLiveImplContent));
+    InvocationContext invocationContext = TestUtils.createInvocationContext(agent);
+
+    List<Event> results = agent.runLive(invocationContext).toList().blockingGet();
+
+    assertThat(results).hasSize(1);
+    assertThat(results.get(0).content()).hasValue(runLiveImplContent);
+    assertThat(runLiveImpl.wasCalled()).isTrue();
+  }
 }

core/src/test/java/com/google/adk/agents/ConfigAgentUtilsTest.java

@@ -1204,10 +1204,8 @@ public void fromConfig_withConfiguredCallbacks_resolvesCallbacks()
     assertThat(agent).isInstanceOf(LlmAgent.class);
     LlmAgent llm = (LlmAgent) agent;
 
-    assertThat(agent.beforeAgentCallback()).isPresent();
-    assertThat(agent.beforeAgentCallback().get()).hasSize(2);
-    assertThat(agent.afterAgentCallback()).isPresent();
-    assertThat(agent.afterAgentCallback().get()).hasSize(1);
+    assertThat(agent.beforeAgentCallback()).hasSize(2);
+    assertThat(agent.afterAgentCallback()).hasSize(1);
 
     assertThat(llm.beforeModelCallback()).isPresent();
     assertThat(llm.beforeModelCallback().get()).hasSize(1);

core/src/test/java/com/google/adk/testing/TestCallback.java

@@ -102,6 +102,19 @@ public Supplier<Flowable<Event>> asRunAsyncImplSupplier(String contentText) {
     return asRunAsyncImplSupplier(Content.fromParts(Part.fromText(contentText)));
   }
 
+  /**
+   * Returns a {@link Supplier} that marks this callback as called and returns a {@link Flowable}
+   * with an event containing the given content.
+   */
+  public Supplier<Flowable<Event>> asRunLiveImplSupplier(Content content) {
+    return () ->
+        Flowable.defer(
+            () -> {
+              markAsCalled();
+              return Flowable.just(Event.builder().content(content).build());
+            });
+  }
+
   @SuppressWarnings("unchecked") // This cast is safe if T is Content.
   public BeforeAgentCallback asBeforeAgentCallback() {
     return ctx -> (Maybe<Content>) callMaybe();