fix: Content is marked non empty if its first part contains text or inline_data or file_data or func call/response

PiperOrigin-RevId: 835063599

src/google/adk/flows/llm_flows/contents.py

@@ -224,7 +224,8 @@ def _contains_empty_content(event: Event) -> bool:
 
   This can happen to the events that only changed session state.
   When both content and transcriptions are empty, the event will be considered
-  as empty.
+  as empty. The content is considered empty if none of its parts contain text,
+  inline data, file data, function call, or function response.
 
   Args:
     event: The event to check.
@@ -239,7 +240,14 @@ def _contains_empty_content(event: Event) -> bool:
       not event.content
       or not event.content.role
       or not event.content.parts
-      or event.content.parts[0].text == ''
+      or all(
+          not p.text
+          and not p.inline_data
+          and not p.file_data
+          and not p.function_call
+          and not p.function_response
+          for p in [event.content.parts[0]]
+      )
   ) and (not event.output_transcription and not event.input_transcription)
 
 

tests/unittests/flows/llm_flows/test_contents.py

@@ -465,6 +465,43 @@ async def test_events_with_empty_content_are_skipped():
           author="user",
           content=types.UserContent("How are you?"),
       ),
+      # Event with content that has only empty text part
+      Event(
+          invocation_id="inv6",
+          author="user",
+          content=types.Content(parts=[types.Part(text="")], role="model"),
+      ),
+      # Event with content that has only inline data part
+      Event(
+          invocation_id="inv7",
+          author="user",
+          content=types.Content(
+              parts=[
+                  types.Part(
+                      inline_data=types.Blob(
+                          data=b"test", mime_type="image/png"
+                      )
+                  )
+              ],
+              role="user",
+          ),
+      ),
+      # Event with content that has only file data part
+      Event(
+          invocation_id="inv8",
+          author="user",
+          content=types.Content(
+              parts=[
+                  types.Part(
+                      file_data=types.FileData(
+                          file_uri="gs://test_bucket/test_file.png",
+                          mime_type="image/png",
+                      )
+                  )
+              ],
+              role="user",
+          ),
+      ),
   ]
   invocation_context.session.events = events
 
@@ -478,4 +515,23 @@ async def test_events_with_empty_content_are_skipped():
   assert llm_request.contents == [
       types.UserContent("Hello"),
       types.UserContent("How are you?"),
+      types.Content(
+          parts=[
+              types.Part(
+                  inline_data=types.Blob(data=b"test", mime_type="image/png")
+              )
+          ],
+          role="user",
+      ),
+      types.Content(
+          parts=[
+              types.Part(
+                  file_data=types.FileData(
+                      file_uri="gs://test_bucket/test_file.png",
+                      mime_type="image/png",
+                  )
+              )
+          ],
+          role="user",
+      ),
   ]