go — testdino-hq/google-styleguides-skills Agent…

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Google Go Style Guide

Official Google Go coding standards for idiomatic, maintainable code.

Golden Rules

Run `gofmt` before commit — formatting is non-negotiable
Short variable names in small scopes — i, err, ctx
Error handling, not exceptions — check every error
Interfaces for abstraction — accept interfaces, return structs
Defer for cleanup — ensure resources are released
Explicit is better — avoid magic, prefer clarity
Package names: lowercase, single word — no underscores

Quick Reference

Naming Conventions

Element	Convention	Example
Packages	lowercase	`package user`
Files	lowercase_underscore	`user_service.go`
Types	UpperCamelCase	`UserService`
Functions/Methods	UpperCamelCase (exported)	`GetUser`
Functions/Methods	lowerCamelCase (unexported)	`getUserByID`
Variables	lowerCamelCase	`userCount`
Constants	UpperCamelCase or UPPER_SNAKE	`MaxRetries`
Interfaces	UpperCamelCase + -er suffix	`Reader`, `Writer`

Variables

// ✓ CORRECT - short names in small scopes
for i := 0; i < 10; i++ {
    // ...
}

// ✓ CORRECT - descriptive names in larger scopes
func ProcessUserData(userRepository UserRepository) error {
    // ...
}

// ✗ INCORRECT - unnecessarily long
for index := 0; index < 10; index++ {
    // ...
}

Error Handling

// ✓ CORRECT - check every error
user, err := getUser(id)
if err != nil {
    return nil, fmt.Errorf("failed to get user: %w", err)
}

// ✗ INCORRECT - ignoring errors
user, _ := getUser(id)

Functions

// ✓ CORRECT - multiple return values
func GetUser(id int) (*User, error) {
    // ...
}

// ✓ CORRECT - named return values for clarity
func ParseConfig(path string) (cfg *Config, err error) {
    // ...
}

Interfaces

// ✓ CORRECT - small, focused interfaces
type Reader interface {
    Read(p []byte) (n int, err error)
}

// ✓ CORRECT - accept interfaces, return structs
func ProcessData(r Reader) (*Result, error) {
    // ...
}

Defer

// ✓ CORRECT - defer for cleanup
func ReadFile(path string) ([]byte, error) {
    f, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer f.Close()
    
    return io.ReadAll(f)
}

Goroutines and Channels

// ✓ CORRECT - use context for cancellation
func ProcessItems(ctx context.Context, items []Item) error {
    for _, item := range items {
        select {
        case <-ctx.Done():
            return ctx.Err()
        default:
            if err := process(item); err != nil {
                return err
            }
        }
    }
    return nil
}

// ✓ CORRECT - buffered channels when appropriate
results := make(chan Result, len(items))

Package Organization

// ✓ CORRECT - package comment
// Package user provides user management functionality.
package user

// ✓ CORRECT - group imports
import (
    "context"
    "fmt"
    
    "github.com/pkg/errors"
    
    "myapp/internal/db"
)

Common Mistakes

Mistake	Correct Approach
Ignoring errors	Check every error
Long variable names in loops	Use short names (`i`, `j`)
Panic for normal errors	Return errors
Naked returns	Use explicit returns
Not running gofmt	Always format code
Underscores in package names	Use single lowercase word

When to Use This Guide

Writing new Go code
Refactoring existing Go
Code reviews
Setting up linting rules (golangci-lint)
Onboarding new team members

Install

bash

npx skills add testdino-hq/google-styleguides-skills/go

Full Guide

See go.md for complete details, examples, and edge cases.