Go Language Expertise

Overview

Idiomatic, production-grade Go: concurrency, error handling, interfaces, testing, and version-gated behavior. The Foundations below get code working; the Expert Practices section is the higher bar — each item states the mechanism so you can apply it beyond the case shown.

Foundations

Error Handling

// Sentinel errors for identity checks; custom types for structured context.
var ErrNotFound = errors.New("resource not found")

type ValidationError struct{ Field, Message string }

func (e *ValidationError) Error() string {
    return fmt.Sprintf("validation on %s: %s", e.Field, e.Message)
}