golang-idiomatic-go

Golang Idiomatic Patterns

Expert-level review for idiomatic Go patterns. Ensures code follows Go conventions, proper interface design, and appropriate pointer usage.

When to Apply

Use this skill when:

• Ensuring code follows Go idioms
• Reviewing interface design patterns
• Checking pointer vs value usage
• Verifying "Accept interfaces, return structs" pattern
• Auditing usecase complexity
• Ensuring small, focused interfaces

Rule Categories by Priority

Priority	Count	Focus
High	1	Method receivers
Medium	5	Go idioms and patterns

Rules Covered (6 total)

High-Impact Patterns (1)

• high-pointer-receiver - Use pointer receivers for mutations

Medium Improvements (5)

• medium-interface-pollution - Keep interfaces small (<5 methods)
• medium-accept-interface-return-struct - API flexibility pattern
• medium-pointer-overuse - Don't overuse pointers for small types
• medium-usecase-complexity - Move business logic to domain entities
• medium-interface-in-implementation - Define interfaces where used

Common Idiomatic Patterns

Accept Interfaces, Return Structs

// ✅ GOOD: Accept interface, return struct
func Process(r io.Reader) (*Result, error) {
    // ...
    return &Result{}, nil
}

Small Interfaces

// ✅ GOOD: Small, focused interface
type Reader interface {
    Read(p []byte) (n int, err error)
}

Pointer Receivers for Mutations

// ✅ GOOD: Pointer receiver modifies state
func (u *User) UpdateEmail(email string) {
    u.Email = email
}

Trigger Phrases

This skill activates when you say:

• "Is this idiomatic Go?"
• "Review Go style"
• "Check interface design"
• "Verify pointer usage"
• "Review Go conventions"
• "Check for Go anti-patterns"

How to Use

For Idiomatic Review

1. Check method receivers (pointer vs value)
2. Verify interface sizes and locations
3. Review pointer usage appropriateness
4. Check "accept interfaces, return structs" pattern