Coverage for little_loops / hooks / pre_tool_use.py: 100%

1"""PreToolUse hook handler: no-op baseline for opt-in synchronous observability. 

2 

3Per FEAT-1489 (and FEAT-1488 research), this handler is registered as the 

4pre-tool-use intent so future consumers (rate-limit enforcement, permission 

5checks, tool-argument validation) can extend it. Today it returns a passing 

6result with no side effects. 

7 

8**Opt-in only**: unlike ``post_tool_use``, this handler runs *synchronously* 

9in the host's tool-execution path. The OpenCode adapter benchmark measured 

10cold-start p95 ≈ 10ms (well below the 200ms target), so the cost when 

11disabled is bounded — but users must explicitly opt in by editing host 

12config to dispatch ``tool.execute.before`` (OpenCode) or ``PreToolUse`` 

13(Codex) to this intent. By default, neither adapter dispatches it. 

14 

15See ``hooks/adapters/opencode/README.md`` and 

16``hooks/adapters/codex/README.md`` for opt-in instructions. 

17""" 

18 

19from __future__ import annotations 

20 

21from little_loops.hooks.types import LLHookEvent, LLHookResult 

22 

23 

24def handle(event: LLHookEvent) -> LLHookResult: 

25 """Return a passing result. No-op baseline for future opt-in consumers.""" 

26 del event 

27 return LLHookResult(exit_code=0)