refactor: BaseAgent: Apply Java style, fix a unit test, add a unit test

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

@@ -76,7 +76,7 @@ public abstract class BaseAgent {
   public BaseAgent(
       String name,
       String description,
-      List<? extends BaseAgent> subAgents,
+      @Nullable List<? extends BaseAgent> subAgents,
       @Nullable List<? extends BeforeAgentCallback> beforeAgentCallback,
       @Nullable List<? extends AfterAgentCallback> afterAgentCallback) {
     this.name = name;

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 runLiveCallback = 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(),
+            runLiveCallback.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(runLiveCallback.wasCalled()).isTrue();
+  }
 }

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

@@ -102,63 +102,80 @@ 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();
+    return (unusedCtx) -> (Maybe<Content>) callMaybe();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Content.
   public BeforeAgentCallbackSync asBeforeAgentCallbackSync() {
-    return ctx -> (Optional<Content>) callOptional();
+    return (unusedCtx) -> (Optional<Content>) callOptional();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Content.
   public AfterAgentCallback asAfterAgentCallback() {
-    return ctx -> (Maybe<Content>) callMaybe();
+    return (unusedCtx) -> (Maybe<Content>) callMaybe();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Content.
   public AfterAgentCallbackSync asAfterAgentCallbackSync() {
-    return ctx -> (Optional<Content>) callOptional();
+    return (unusedCtx) -> (Optional<Content>) callOptional();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is LlmResponse.
   public BeforeModelCallback asBeforeModelCallback() {
-    return (ctx, req) -> (Maybe<LlmResponse>) callMaybe();
+    return (unusedCtx, unusedReq) -> (Maybe<LlmResponse>) callMaybe();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is LlmResponse.
   public BeforeModelCallbackSync asBeforeModelCallbackSync() {
-    return (ctx, req) -> (Optional<LlmResponse>) callOptional();
+    return (unusedCtx, unusedReq) -> (Optional<LlmResponse>) callOptional();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is LlmResponse.
   public AfterModelCallback asAfterModelCallback() {
-    return (ctx, res) -> (Maybe<LlmResponse>) callMaybe();
+    return (unusedCtx, unusedRes) -> (Maybe<LlmResponse>) callMaybe();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is LlmResponse.
   public AfterModelCallbackSync asAfterModelCallbackSync() {
-    return (ctx, res) -> (Optional<LlmResponse>) callOptional();
+    return (unusedCtx, unusedRes) -> (Optional<LlmResponse>) callOptional();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Map<String, Object>.
   public BeforeToolCallback asBeforeToolCallback() {
-    return (invCtx, tool, toolArgs, toolCtx) -> (Maybe<Map<String, Object>>) callMaybe();
+    return (unusedCtx, unusedTool, unusedToolArgs, unusedToolCtx) ->
+        (Maybe<Map<String, Object>>) callMaybe();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Map<String, Object>.
   public BeforeToolCallbackSync asBeforeToolCallbackSync() {
-    return (invCtx, tool, toolArgs, toolCtx) -> (Optional<Map<String, Object>>) callOptional();
+    return (unusedCtx, unusedTool, unusedToolArgs, unusedToolCtx) ->
+        (Optional<Map<String, Object>>) callOptional();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Map<String, Object>.
   public AfterToolCallback asAfterToolCallback() {
-    return (invCtx, tool, toolArgs, toolCtx, res) -> (Maybe<Map<String, Object>>) callMaybe();
+    return (unusedCtx, unusedTool, unusedToolArgs, unusedToolCtx, unusedRes) ->
+        (Maybe<Map<String, Object>>) callMaybe();
   }
 
   @SuppressWarnings("unchecked") // This cast is safe if T is Map<String, Object>.
   public AfterToolCallbackSync asAfterToolCallbackSync() {
-    return (invCtx, tool, toolArgs, toolCtx, res) -> (Optional<Map<String, Object>>) callOptional();
+    return (unusedCtx, unusedTool, unusedToolArgs, unusedToolCtx, unusedRes) ->
+        (Optional<Map<String, Object>>) callOptional();
   }
 }