fix: add additional stack checks

lib/crewai/tests/events/test_event_context.py

@@ -0,0 +1,99 @@
+"""Tests for event context management."""
+
+import pytest
+
+from crewai.events.event_context import (
+    SCOPE_ENDING_EVENTS,
+    SCOPE_STARTING_EVENTS,
+    VALID_EVENT_PAIRS,
+    EmptyStackError,
+    EventPairingError,
+    MismatchBehavior,
+    StackDepthExceededError,
+    _event_context_config,
+    EventContextConfig,
+    get_current_parent_id,
+    get_enclosing_parent_id,
+    handle_empty_pop,
+    handle_mismatch,
+    pop_event_scope,
+    push_event_scope,
+)
+
+
+class TestStackOperations:
+    """Tests for stack push/pop operations."""
+
+    def test_empty_stack_returns_none(self) -> None:
+        assert get_current_parent_id() is None
+        assert get_enclosing_parent_id() is None
+
+    def test_push_and_get_parent(self) -> None:
+        push_event_scope("event-1", "task_started")
+        assert get_current_parent_id() == "event-1"
+
+    def test_nested_push(self) -> None:
+        push_event_scope("event-1", "crew_kickoff_started")
+        push_event_scope("event-2", "task_started")
+        assert get_current_parent_id() == "event-2"
+        assert get_enclosing_parent_id() == "event-1"
+
+    def test_pop_restores_parent(self) -> None:
+        push_event_scope("event-1", "crew_kickoff_started")
+        push_event_scope("event-2", "task_started")
+        popped = pop_event_scope()
+        assert popped == ("event-2", "task_started")
+        assert get_current_parent_id() == "event-1"
+
+    def test_pop_empty_stack_returns_none(self) -> None:
+        assert pop_event_scope() is None
+
+
+class TestStackDepthLimit:
+    """Tests for stack depth limit."""
+
+    def test_depth_limit_exceeded_raises(self) -> None:
+        _event_context_config.set(EventContextConfig(max_stack_depth=3))
+
+        push_event_scope("event-1", "type-1")
+        push_event_scope("event-2", "type-2")
+        push_event_scope("event-3", "type-3")
+
+        with pytest.raises(StackDepthExceededError):
+            push_event_scope("event-4", "type-4")
+
+
+class TestMismatchHandling:
+    """Tests for mismatch behavior."""
+
+    def test_handle_mismatch_raises_when_configured(self) -> None:
+        _event_context_config.set(
+            EventContextConfig(mismatch_behavior=MismatchBehavior.RAISE)
+        )
+
+        with pytest.raises(EventPairingError):
+            handle_mismatch("task_completed", "llm_call_started", "task_started")
+
+    def test_handle_empty_pop_raises_when_configured(self) -> None:
+        _event_context_config.set(
+            EventContextConfig(empty_pop_behavior=MismatchBehavior.RAISE)
+        )
+
+        with pytest.raises(EmptyStackError):
+            handle_empty_pop("task_completed")
+
+
+class TestEventTypeSets:
+    """Tests for event type set completeness."""
+
+    def test_all_ending_events_have_pairs(self) -> None:
+        for ending_event in SCOPE_ENDING_EVENTS:
+            assert ending_event in VALID_EVENT_PAIRS
+
+    def test_all_pairs_reference_starting_events(self) -> None:
+        for ending_event, starting_event in VALID_EVENT_PAIRS.items():
+            assert starting_event in SCOPE_STARTING_EVENTS
+
+    def test_starting_and_ending_are_disjoint(self) -> None:
+        overlap = SCOPE_STARTING_EVENTS & SCOPE_ENDING_EVENTS
+        assert not overlap