feat: migrate invocation_context to callback_context

Update plugin manager and built-in plugins to prioritize CallbackContext. Keep InvocationContext access for legacy plugins with adapter. Change callback docs/tests to cover the new context.

PiperOrigin-RevId: 818798087

tests/unittests/plugins/test_base_plugin.py

@@ -103,19 +103,15 @@ async def test_base_plugin_default_callbacks_return_none():
   assert (
       await plugin.on_user_message_callback(
           user_message=mock_user_message,
-          invocation_context=mock_context,
+          callback_context=mock_context,
       )
       is None
   )
-  assert (
-      await plugin.before_run_callback(invocation_context=mock_context) is None
-  )
-  assert (
-      await plugin.after_run_callback(invocation_context=mock_context) is None
-  )
+  assert await plugin.before_run_callback(callback_context=mock_context) is None
+  assert await plugin.after_run_callback(callback_context=mock_context) is None
   assert (
       await plugin.on_event_callback(
-          invocation_context=mock_context, event=mock_context
+          callback_context=mock_context, event=mock_context
       )
       is None
   )
@@ -200,25 +196,21 @@ async def test_base_plugin_all_callbacks_can_be_overridden():
   assert (
       await plugin.on_user_message_callback(
           user_message=mock_user_message,
-          invocation_context=mock_invocation_context,
+          callback_context=mock_callback_context,
       )
       == "overridden_on_user_message"
   )
   assert (
-      await plugin.before_run_callback(
-          invocation_context=mock_invocation_context
-      )
+      await plugin.before_run_callback(callback_context=mock_callback_context)
       == "overridden_before_run"
   )
   assert (
-      await plugin.after_run_callback(
-          invocation_context=mock_invocation_context
-      )
+      await plugin.after_run_callback(callback_context=mock_callback_context)
       == "overridden_after_run"
   )
   assert (
       await plugin.on_event_callback(
-          invocation_context=mock_invocation_context, event=mock_event
+          callback_context=mock_callback_context, event=mock_event
       )
       == "overridden_on_event"
   )

tests/unittests/plugins/test_global_instruction_plugin.py

@@ -43,7 +43,7 @@ async def test_global_instruction_plugin_with_string():
   mock_invocation_context.session = mock_session
 
   mock_callback_context = Mock(spec=CallbackContext)
-  mock_callback_context.invocation_context = mock_invocation_context
+  mock_callback_context._invocation_context = mock_invocation_context
 
   llm_request = LlmRequest(
       model="gemini-1.5-flash",
@@ -70,7 +70,7 @@ async def test_global_instruction_plugin_with_instruction_provider():
   """Test GlobalInstructionPlugin with an InstructionProvider function."""
 
   async def build_global_instruction(readonly_context: ReadonlyContext) -> str:
-    return f"You are assistant for user {readonly_context.session.user_id}."
+    return f"You are assistant for user {readonly_context.user_id}."
 
   plugin = GlobalInstructionPlugin(global_instruction=build_global_instruction)
 
@@ -83,7 +83,8 @@ async def test_global_instruction_plugin_with_instruction_provider():
   mock_invocation_context.session = mock_session
 
   mock_callback_context = Mock(spec=CallbackContext)
-  mock_callback_context.invocation_context = mock_invocation_context
+  mock_callback_context._invocation_context = mock_invocation_context
+  mock_callback_context.user_id = "alice"
 
   llm_request = LlmRequest(
       model="gemini-1.5-flash",
@@ -119,7 +120,7 @@ async def test_global_instruction_plugin_empty_instruction():
   mock_invocation_context.session = mock_session
 
   mock_callback_context = Mock(spec=CallbackContext)
-  mock_callback_context.invocation_context = mock_invocation_context
+  mock_callback_context._invocation_context = mock_invocation_context
 
   llm_request = LlmRequest(
       model="gemini-1.5-flash",
@@ -156,7 +157,7 @@ async def test_global_instruction_plugin_leads_existing():
   mock_invocation_context.session = mock_session
 
   mock_callback_context = Mock(spec=CallbackContext)
-  mock_callback_context.invocation_context = mock_invocation_context
+  mock_callback_context._invocation_context = mock_invocation_context
 
   llm_request = LlmRequest(
       model="gemini-1.5-flash",
@@ -191,7 +192,7 @@ async def test_global_instruction_plugin_prepends_to_list():
   mock_invocation_context.session = mock_session
 
   mock_callback_context = Mock(spec=CallbackContext)
-  mock_callback_context.invocation_context = mock_invocation_context
+  mock_callback_context._invocation_context = mock_invocation_context
 
   llm_request = LlmRequest(
       model="gemini-1.5-flash",

tests/unittests/test_runners.py

@@ -15,8 +15,8 @@
 from typing import Optional
 
 from google.adk.agents.base_agent import BaseAgent
+from google.adk.agents.callback_context import CallbackContext
 from google.adk.agents.context_cache_config import ContextCacheConfig
-from google.adk.agents.invocation_context import InvocationContext
 from google.adk.agents.llm_agent import LlmAgent
 from google.adk.apps.app import App
 from google.adk.apps.app import ResumabilityConfig
@@ -98,7 +98,7 @@ class MockPlugin(BasePlugin):
   async def on_user_message_callback(
       self,
       *,
-      invocation_context: InvocationContext,
+      callback_context: CallbackContext,
       user_message: types.Content,
   ) -> Optional[types.Content]:
     if not self.enable_user_message_callback:
@@ -109,7 +109,7 @@ class MockPlugin(BasePlugin):
     )
 
   async def on_event_callback(
-      self, *, invocation_context: InvocationContext, event: Event
+      self, *, callback_context: CallbackContext, event: Event
   ) -> Optional[Event]:
     if not self.enable_event_callback:
       return None