# Todo 43.2 Remove Legacy Event Consumption Plan

**Status:** done

## Result

- Removed legacy `event` acceptance from Runtime and EventAgent production consumers.
- Added wrong-source negative coverage.
- Added a real chat-client `[DONE]` integration test for compatible providers without `finish_reason`.
- Focused tests pass (`77 passed`) and the full suite passes (`82 passed`, one existing warning).

## Goal

Enforce typed event-source isolation at production consumer boundaries so the legacy compatibility constructor cannot silently mask incorrect ChatAgent or EventAgent wiring.

## Scope

- Runtime accepts only `text_event` from ChatAgent streams.
- EventAgent accepts only `provider_tool_call` from its provider-tools argument request.
- Remaining runtime/WebSocket test fixtures use the correct typed constructor.
- Add negative tests for wrong-source events.
- Add one chat-client SSE integration test proving `[DONE]` flush emits one provider tool call when no finish reason is present.
- Keep the legacy constructor temporarily for unrelated external callers, but production consumers must not accept it.

## Files

- Modify: `src/agent_lab/application/runtime.py`
- Modify: `src/agent_lab/application/event_agent.py`
- Modify: `tests/test_debug_runtime.py`
- Modify: `tests/test_event_agent.py`
- Modify: `tests/test_websocket_api.py`

## Plan

### Plan

1. Replace remaining production-path legacy fixtures with typed constructors.
2. Add negative tests that wrong-source and legacy events do not cross the consumer boundaries.
3. Add a MockTransport/SSE `[DONE]` integration test for the real chat client.
4. Verify RED failures expose the three legacy consumer branches.
5. Remove legacy consumption from Runtime/EventAgent and run all regressions.

### Act

- Runtime tests: emit `provider_tool_call` and legacy `event` from the ChatAgent fake and assert no tool handoff occurs; keep the positive `text_event` test.
- EventAgent tests: emit `text_event`/legacy `event` from its provider fake and assert it falls back rather than treating either as resolved provider arguments; keep the positive provider call test.
- WebSocket/client tests: replace legacy fixtures with typed constructors and add SSE chunks with provider tool calls, no `finish_reason`, then `[DONE]`; assert exactly one `provider_tool_call`.
- Run focused tests and confirm expected failure before production changes.
- Remove `event` from consumer condition sets.
- Re-run focused and full tests.

### Observe

Confirm typed-source isolation is enforced by negative tests and that no remaining production-path fixture relies on `StreamItem.event(...)`.

### Update

- Mark 43, 43.1, and 43.2 `done` only after renewed spec and quality review.
- Commit separately with the masked-regression risk in the message.

## Verification

- `uv run pytest tests/test_debug_runtime.py tests/test_event_agent.py tests/test_websocket_api.py tests/test_openai_stream_parser.py -q`
- `uv run pytest`
- `git diff --check`