go-best-practices

name	go-best-practices
description	Go coding best practices. Use when writing or reviewing Go code. Covers error handling, concurrency, and idiomatic patterns.
license	MIT
metadata	{"author":"plan-cascade","version":"1.0.0"}

Go Best Practices

Code Style

Rule	Guideline
Formatter	gofmt or goimports
Linter	golangci-lint
Naming	Short, clear; avoid stuttering
Comments	Godoc for exported items

Error Handling

Rule	Guideline
Always check	Never ignore errors
Wrap context	fmt.Errorf("ctx: %w", err)
Sentinel errors	var ErrNotFound = errors.New(...)

func Load(path string) (*Config, error) {
    data, err := os.ReadFile(path)
    if err != nil {
        return nil, fmt.Errorf("load config %s: %w", path, err)
    }
    // ...
}

Project Structure

cmd/appname/main.go
internal/config/
internal/service/
go.mod

Concurrency

Pattern	Usage
context.Context	Cancellation, timeouts
sync.WaitGroup	Wait for goroutines
errgroup.Group	Goroutines with errors

func Process(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
}

Anti-Patterns

Avoid	Use Instead
Naked returns	Explicit returns
panic for errors	Return errors
Large interfaces	Small, focused
init()	Explicit init

Testing (Table-Driven)

func TestParse(t *testing.T) {
    tests := []struct{ name, input string; want int; wantErr bool }{
        {"valid", "42", 42, false},
        {"invalid", "abc", 0, true},
    }
    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            got, err := Parse(tt.input)
            if (err != nil) != tt.wantErr { t.Errorf("err=%v, want=%v", err, tt.wantErr) }
            if got != tt.want { t.Errorf("got=%v, want=%v", got, tt.want) }
        })
    }
}