error-boundaries_skill

Overview

This skill helps you decide where to catch errors by treating catches as architectural boundaries rather than random local guards. It teaches where to let errors propagate, where to translate or recover, and how to isolate failures for graceful degradation. Follow it to prevent hidden bugs and cascading failures while keeping business logic clean.

How this skill works

The guidance inspects your codebase for context transitions and recommends placing try/catch at those boundaries: entry points (HTTP, message consumers), external adapters, and UI component boundaries. It flags scattered catches inside services, repositories, or utility functions and suggests moving handling to top-level middleware, adapters, or error boundaries that can translate, log, and recover meaningfully.

When to use it

• Designing application architecture and error handling strategy
• Deciding whether to add a try/catch in a service, repo, or utility
• Isolating components so one failure doesn't crash unrelated features
• Implementing graceful degradation for optional features
• Mapping where errors should be translated, logged, or converted to domain errors

Best practices

• Place catches only at context transitions (HTTP middleware, adapters, UI ErrorBoundary)
• Let pure business logic, services, and repositories throw errors rather than swallow them
• Translate external errors to domain-specific errors in adapters, not in business code
• Use boundaries for fallbacks: only optional features get local try/catch for graceful degradation
• Avoid catch-and-rethrow unless you add genuinely useful context

Example use cases

• Top-level HTTP error middleware translates ValidationError, NotFoundError, UnauthorizedError to proper responses
• Payment gateway adapter catches provider errors and throws PaymentDeclinedError or PaymentServiceUnavailableError
• React ErrorBoundary isolates Dashboard and Sidebar so one UI failure doesn’t crash the whole app
• Recommendation service wrapped at boundary to log failures and return empty recommendations without failing the page
• Message queue consumer that catches, logs, and decides ack/nack at the entry boundary