R15.2: Non-blocking third-party failures

Short answer: External widgets render graceful placeholder on failure. If a chat widget fails to load, the rest of the page must still work.

Group: Error boundaries and fallback rendering. Status: stable. Generated from the rule definitions; do not edit by hand.

Playground: https://brevio.pro/tools/agent-guard-playground?rule=R15.2

What it catches

Non-blocking third-party failures: external widgets render graceful placeholder on failure.

Why

If a chat widget fails to load, the rest of the page must still work.

A bad example

<ChatWidget />

A good example

<ErrorBoundary fallback={null}><ChatWidget /></ErrorBoundary>

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 R15.2 -- 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.

R15.3 Form submit recovery
R15.4 Image broken state fallback
R15.5 Network offline banner
R15.6 Empty state affordance
Every rule