fix: Fixed issue where events were marked empty if the first part had an empty text; now checks all parts for meaningful content

google-genai-bot · copybara-github · commit a0cba25d691f · 2026-03-04T02:05:24.000-08:00
PiperOrigin-RevId: 878371150
diff --git a/core/src/main/java/com/google/adk/flows/llmflows/Contents.java b/core/src/main/java/com/google/adk/flows/llmflows/Contents.java
@@ -169,7 +169,36 @@ private boolean isEmptyContent(Event event) {
         || content.role().get().isEmpty()
         || content.parts().isEmpty()
         || content.parts().get().isEmpty()
-        || content.parts().get().get(0).text().map(String::isEmpty).orElse(false));
+        || content.parts().get().stream().allMatch(this::isPartInvisible));
+  }
+
+  /**
+   * Returns whether a part is invisible for LLM context.
+   *
+   * <p>A part is invisible if:
+   *
+   * <ul>
+   *   <li>It has no meaningful content (text, inline_data, file_data, function_call,
+   *       function_response, executable_code, or code_execution_result), OR
+   *   <li>It is marked as a thought AND does not contain function_call or function_response
+   * </ul>
+   *
+   * <p>Function calls and responses are never invisible, even if marked as thought, because they
+   * represent actions that need to be executed or results that need to be processed.
+   *
+   * @param part the part to check.
+   * @return {@code true} if the part is invisible, {@code false} otherwise.
+   */
+  private boolean isPartInvisible(Part part) {
+    if (part.functionCall().isPresent() || part.functionResponse().isPresent()) {
+      return false;
+    }
+    return part.thought().orElse(false)
+        || !(part.text().isPresent()
+            || part.inlineData().isPresent()
+            || part.fileData().isPresent()
+            || part.codeExecutionResult().isPresent()
+            || part.executableCode().isPresent());
   }
 
   /**
diff --git a/core/src/test/java/com/google/adk/flows/llmflows/ContentsTest.java b/core/src/test/java/com/google/adk/flows/llmflows/ContentsTest.java
@@ -754,6 +754,32 @@ public void processRequest_slidingWindow_preservesOverlappingCompactions() {
         .containsExactly("C1", "C2", "E4", "E5");
   }
 
+  @Test
+  public void processRequest_notEmptyContent() {
+    Event e =
+        Event.builder()
+            .id("e1")
+            .author(AGENT)
+            .content(
+                Content.builder()
+                    .role("model")
+                    .parts(
+                        ImmutableList.of(
+                            Part.builder().text("").thought(true).build(),
+                            Part.builder()
+                                .functionCall(
+                                    FunctionCall.builder()
+                                        .name("test-tool")
+                                        .id("test-call-id")
+                                        .build())
+                                .thought(false)
+                                .build()))
+                    .build())
+            .build();
+    List<Content> contents = runContentsProcessor(ImmutableList.of(e));
+    assertThat(contents).containsExactly(e.content().get());
+  }
+
   private static Event createUserEvent(String id, String text) {
     return Event.builder()
         .id(id)
