ppyt db82b59254
fix(middleware): handle list-type AIMessage.content in LoopDetectionMiddleware (#1823)
* fix: inject longTermBackground into memory prompt

The format_memory_for_injection function only processed recentMonths and
earlierContext from the history section, silently dropping longTermBackground.

The LLM writes longTermBackground correctly and it persists to memory.json,
but it was never injected into the system prompt — making the user's
long-term background invisible to the AI.

Add the missing field handling and a regression test.

* fix(middleware): handle list-type AIMessage.content in LoopDetectionMiddleware

LangChain AIMessage.content can be str | list. When using providers that
return structured content blocks (e.g. Anthropic thinking mode, certain
OpenAI-compatible gateways), content is a list of dicts like
[{"type": "text", "text": "..."}].

The hard_limit branch in _apply() concatenated content with a string via
(last_msg.content or "") + f"\n\n{_HARD_STOP_MSG}", which raises
TypeError when content is a non-empty list (list + str is invalid).

Add _append_text() static method that:
- Returns the text directly when content is None
- Appends a {"type": "text"} block when content is a list
- Falls back to string concatenation when content is a str

This is consistent with how other modules in the project already handle
list content (client.py._extract_text, memory_middleware, executor.py).

* test(middleware): add unit tests for _append_text and list content hard stop

Add regression tests to verify LoopDetectionMiddleware handles list-type
AIMessage.content correctly during hard stop:

- TestAppendText: unit tests for the new _append_text() static method
  covering None, str, list (including empty list) content types
- TestHardStopWithListContent: integration tests verifying hard stop
  works correctly with list content (Anthropic thinking mode), None
  content, and str content

Requested by reviewer in PR #1823.

* fix(middleware): improve _append_text robustness and test isolation

- Add explicit isinstance(content, str) check with fallback for
  unexpected types (coerce to str) to prevent TypeError on edge cases
- Deep-copy list content in _make_state() test helper to prevent
  shared mutable references across test iterations
- Add test_unexpected_type_coerced_to_str: verify fallback for
  non-str/list/None content types
- Add test_list_content_not_mutated_in_place: verify _append_text
  does not modify the original list

* style: fix ruff format whitespace in test file

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Co-authored-by: ppyt <14163465+ppyt@users.noreply.github.com>
2026-04-04 10:38:22 +08:00
..