golang-patterns

# Go Development Patterns Idiomatic Go patterns and best practices for building robust, efficient, and maintainable applications. ## When to Activate - Writing new Go code - Reviewing Go code - Refactoring existing Go code - Designing Go packages/modules ## Core Principles ### 1. Simplicity and Clarity Go favors simplicity over cleverness. Code should be obvious and easy to read. ```go // Good: Clear and direct func GetUser(id string) (*User, error) { user, err := db.FindUser(id) if err != nil { return nil, fmt.Errorf("get user %s: %w", id, err) } return user, nil } // Bad: Overly clever func GetUser(id string) (*User, error) { return func() (*User, error) { if u, e := db.FindUser(id); e == nil { return u, nil } else { return nil, e } }() } ``` ### 2. Make the Zero Value Useful Design types so their zero value is immediately usable without initialization. ```go // Good: Zero value is useful type Counter struct { mu sync.Mutex count int // zero value is 0, ready to use } func (c *Counter) Inc() { c.mu.Lock() c.count++ c.mu.Unlock() } // Good: bytes.Buffer works with zero value var buf bytes.Buffer buf.WriteString("hello") // Bad: Requires initialization type BadCounter struct { counts map[string]int // nil map will panic } ``` ### 3. Accept Interfaces, Return Structs Functions should accept interface parameters and return concrete types. ```go // Good: Ac...