fix: Fix infinite loop when using code_executor

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

@@ -227,6 +227,8 @@ def _is_part_invisible(p: types.Part) -> bool:
       or p.file_data
       or p.function_call
       or p.function_response
+      or p.executable_code
+      or p.code_execution_result
   )
 
 
@@ -452,7 +454,49 @@ def _get_contents(
     if content:
       remove_client_function_call_id(content)
       contents.append(content)
-  return contents
+
+  # Merge consecutive model contents when they contain code execution parts.
+  # This is necessary for code execution where executable_code and
+  # code_execution_result are separate events but need to be in the same
+  # Content for the LLM to understand the execution flow.
+  merged_contents = []
+  for content in contents:
+    if (
+        merged_contents
+        and merged_contents[-1].role == content.role
+        and content.role == 'model'
+        and _should_merge_code_execution_content(merged_contents[-1], content)
+    ):
+      # Merge parts into the previous content
+      merged_contents[-1].parts.extend(content.parts)
+    else:
+      merged_contents.append(content)
+
+  return merged_contents
+
+
+def _content_has_code_execution_part(content: types.Content) -> bool:
+  """Check if a content has executable_code or code_execution_result parts."""
+  if not content.parts:
+    return False
+  for part in content.parts:
+    if part.executable_code or part.code_execution_result:
+      return True
+  return False
+
+
+def _should_merge_code_execution_content(
+    prev_content: types.Content, curr_content: types.Content
+) -> bool:
+  """Determine if two consecutive model contents should be merged.
+
+  Only merge when the previous content has executable_code and the current
+  content has code_execution_result. This ensures proper code execution flow
+  is maintained without affecting other consecutive model messages.
+  """
+  return _content_has_code_execution_part(
+      prev_content
+  ) or _content_has_code_execution_part(curr_content)
 
 
 def _get_current_turn_contents(

tests/unittests/flows/llm_flows/test_contents.py

@@ -609,3 +609,76 @@ async def test_events_with_empty_content_are_skipped():
           role="user",
       ),
   ]
+
+
+@pytest.mark.asyncio
+async def test_events_with_code_execution_are_included():
+  """Test that events with executable_code and code_execution_result are included."""
+  agent = Agent(model="gemini-2.5-flash", name="test_agent")
+  llm_request = LlmRequest(model="gemini-2.5-flash")
+  invocation_context = await testing_utils.create_invocation_context(
+      agent=agent
+  )
+
+  events = [
+      Event(
+          invocation_id="inv1",
+          author="user",
+          content=types.UserContent("Run some code"),
+      ),
+      # Event with executable_code part
+      Event(
+          invocation_id="inv2",
+          author="test_agent",
+          content=types.Content(
+              parts=[
+                  types.Part(
+                      executable_code=types.ExecutableCode(
+                          code="print('hello')",
+                          language="PYTHON",
+                      )
+                  )
+              ],
+              role="model",
+          ),
+      ),
+      # Event with code_execution_result part
+      Event(
+          invocation_id="inv3",
+          author="test_agent",
+          content=types.Content(
+              parts=[
+                  types.Part(
+                      code_execution_result=types.CodeExecutionResult(
+                          outcome="OUTCOME_OK",
+                          output="hello",
+                      )
+                  )
+              ],
+              role="model",
+          ),
+      ),
+      Event(
+          invocation_id="inv4",
+          author="user",
+          content=types.UserContent("What was the result?"),
+      ),
+  ]
+  invocation_context.session.events = events
+
+  # Process the request
+  async for _ in contents.request_processor.run_async(
+      invocation_context, llm_request
+  ):
+    pass
+
+  # Verify events with executable_code and code_execution_result are included
+  # Consecutive model contents are merged into one content with multiple parts
+  assert len(llm_request.contents) == 3
+  assert llm_request.contents[0] == types.UserContent("Run some code")
+  # The merged model content should have both executable_code and code_execution_result
+  assert llm_request.contents[1].role == "model"
+  assert len(llm_request.contents[1].parts) == 2
+  assert llm_request.contents[1].parts[0].executable_code is not None
+  assert llm_request.contents[1].parts[1].code_execution_result is not None
+  assert llm_request.contents[2] == types.UserContent("What was the result?")