golang-error-handling

The best way to handle errors in a layered Go service is wrapping them with the %w verb to preserve context, then inspecting the chain using errors.Is and errors.As to match sentinels and extract typed errors.

To combine independent failures in golang error handling, use errors.Join to aggregate multiple distinct errors into a single error value, allowing you to report concurrent or parallel failures without losing individual error context.

To prevent duplicate structured logs for the same Go error, apply the single-handling rule: wrap the error with context at lower layers and log it only once at the application boundary using structured logging.

Use errors.Is to check if an error in the chain matches a specific sentinel error value, while errors.As is used to extract a specific typed error from the chain, allowing you to access custom fields on the structured error.

Yes, this error handling approach enforces lowercase error strings to maintain consistency and low cardinality, ensuring that wrapped error chains remain clean, debuggable, and production-safe.

Yes, you can use structured slog or oops context to attach key-value pairs to wrapped Go errors, enriching the failure logs with operational context without exposing internal system details to the end user.