go-error-handling-patterns

Standardize Go error handling by implementing a unified AppError type with consistent Code, Message, Detail, and HTTPStatus fields. This approach eliminates duplicated logic across services, ensuring consistent error responses and stack traces for debugging.

Map domain errors to HTTP status codes using predefined constructors like NotFound, Validation, Unauthorized, and Forbidden. These constructors automatically assign the correct HTTPStatus to your AppError, streamlining HTTP handler responses.

Wrap Go errors using fmt.Errorf with the %w verb to preserve the error chain. This allows errors.Is and errors.As to traverse the wrapped errors, maintaining domain semantics through sentinel errors and an error catalog.

Prevent PII leaks by keeping internal details in non-serialized fields within the AppError type. This ensures only user-safe messages are emitted to clients, while sensitive information remains accessible internally for debugging.

Use sentinel errors for specific expected values and an error catalog to centralize domain semantics across services. Both reduce duplication, but the catalog groups broader domain categories while sentinels handle exact error matching via errors.Is.