Catches the mistakes coding agents repeat before they merge: a pull-request gate with no model call and no API key.
Short answer: Every bug fix includes a failing-first test. A bug without a test comes back.
Group: Testing and hermeticity. Status: stable. Generated from the rule definitions; do not edit by hand.
Playground: https://brevio.pro/tools/agent-guard-playground?rule=R6.5
Post-incident regression crystallization: every bug fix includes a failing-first test.
A bug without a test comes back.
fix: handle empty cart (no test)
fix: handle empty cart (adds a test that fails without the fix)
A person can silence one finding with brevio-core: ignore R6.5 -- reason on the line or the line above. Without the reason it does not count. An agent cannot silence it: the agent hook and the MCP tools never honour the comment, and a pull request that adds one is reported until a reviewer allows it. Fixing the code is still the better answer.
To change what the rule flags, edit its definition in dev_rules.py or code_rules/__init__.py. That is a code change and is reviewed like one.