[P0] ZARA-003 — Stop Prolog command execution from reporting false success #4

New issue

Closed

opened 2026-07-18 19:18:15 +00:00 by lost-rob0t · 0 comments

lost-rob0t commented

2026-07-18 19:18:15 +00:00

(Migrated from github.com)

Problem

modules/commands.pl has a catch-all execute(Intent, Args) clause that always succeeds. Unknown or unimplemented intents therefore appear executed and prevent fallback/recovery.

run_system_command/1 catches launch errors, prints a message, then succeeds because of its cut. zara/prolog_engine.py::start_timer() and reload_config() similarly return success without checking query_once().

This creates fake confirmations for commands that did nothing.

Required fix

Remove or replace the success catch-all with an explicit unsupported-intent failure/result.
Make command handlers return failure when the side effect could not be launched.
Preserve explicit handlers only; enumerate currently supported intents.
Propagate structured success/failure through PrologEngine and the wake fallback path.
Do not add new commands in this issue.

Required tests

Prolog tests for known success, unknown intent, missing executable, malformed arguments, and handler exception.
Python tests proving failed Prolog execution falls back instead of returning Executed:.
Add scripts/test-command-routing.sh that runs SWI-Prolog non-interactively against deterministic no-side-effect predicates.

Acceptance

Unknown/unimplemented intents fail closed.
Missing commands do not emit success replies.
Fallback is invoked exactly once after a real failure.
All tests and the command-routing script pass under nix develop.

Branch

fix/zara-003-fail-closed-commands

Dependencies

ZARA-001, ZARA-002.

## Problem `modules/commands.pl` has a catch-all `execute(Intent, Args)` clause that always succeeds. Unknown or unimplemented intents therefore appear executed and prevent fallback/recovery. `run_system_command/1` catches launch errors, prints a message, then succeeds because of its cut. `zara/prolog_engine.py::start_timer()` and `reload_config()` similarly return success without checking `query_once()`. This creates fake confirmations for commands that did nothing. ## Required fix - Remove or replace the success catch-all with an explicit unsupported-intent failure/result. - Make command handlers return failure when the side effect could not be launched. - Preserve explicit handlers only; enumerate currently supported intents. - Propagate structured success/failure through `PrologEngine` and the wake fallback path. - Do not add new commands in this issue. ## Required tests - Prolog tests for known success, unknown intent, missing executable, malformed arguments, and handler exception. - Python tests proving failed Prolog execution falls back instead of returning `Executed:`. - Add `scripts/test-command-routing.sh` that runs SWI-Prolog non-interactively against deterministic no-side-effect predicates. ## Acceptance - Unknown/unimplemented intents fail closed. - Missing commands do not emit success replies. - Fallback is invoked exactly once after a real failure. - All tests and the command-routing script pass under `nix develop`. ## Branch `fix/zara-003-fail-closed-commands` ## Dependencies ZARA-001, ZARA-002.