R11.3: Race condition prevention

Short answer: UI mutations abort pending conflicting requests via AbortController. A slow first request can overwrite the result of a newer one.

Group: State and concurrency. Status: stable. Generated from the rule definitions; do not edit by hand.

Playground: https://brevio.pro/tools/agent-guard-playground?rule=R11.3

What it catches

Race condition prevention: UI mutations abort pending conflicting requests via AbortController.

Why

A slow first request can overwrite the result of a newer one.

A bad example

fetch(url).then(setData);

A good example

ctrl.abort(); ctrl = new AbortController();
fetch(url, { signal: ctrl.signal }).then(setData);

How it is checked

Nothing yet. No scanner and no slice card checks it: it is a standing rule for authors and reviewers.

How to silence it

A person can silence one finding with brevio-core: ignore R11.3 -- 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.

R11.4 Deterministic reducer purity
R11.5 Cache key stability
R11.6 Optimistic UI rollback
R11.7 Bounded in-memory queues
Every rule