Instruction file imported from TakMczk/copilot-cli-ecc (.github/instructions/golang.instructions.md). Copyright stays with the author.

Source: coding-style.md

Go Coding Style

Formatting

• gofmt and goimports are mandatory — no style debates

Design Principles

• Accept interfaces, return structs
• Keep interfaces small (1-3 methods)

Error Handling

Always wrap errors with context:

if err != nil {
    return fmt.Errorf("failed to create user: %w", err)
}

Reference

See skill: golang-patterns for comprehensive Go idioms and patterns.

Source: patterns.md

Go Patterns

Functional Options

type Option func(*Server)

func WithPort(port int) Option {
    return func(s *Server) { s.port = port }
}

func NewServer(opts ...Option) *Server {
    s := &Server{port: 8080}
    for _, opt := range opts {
        opt(s)
    }
    return s
}

Small Interfaces

Define interfaces where they are used, not where they are implemented.

Dependency Injection

Use constructor functions to inject dependencies:

func NewUserService(repo UserRepository, logger Logger) *UserService {
    return &UserService{repo: repo, logger: logger}
}

Reference

See skill: golang-patterns for comprehensive Go patterns including concurrency, error handling, and package organization.

Source: security.md

Go Security

Secret Management

apiKey := os.Getenv("OPENAI_API_KEY")
if apiKey == "" {
    log.Fatal("OPENAI_API_KEY not configured")
}

Security Scanning

• Use gosec for static security analysis:

  gosec ./...

Context & Timeouts

Always use context.Context for timeout control:

ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
defer cancel()

Source: testing.md

Go Testing

Framework

Use the standard go test with table-driven tests.

Race Detection

Always run with the -race flag:

go test -race ./...

Coverage

go test -cover ./...

Reference

See skill: golang-testing for detailed Go testing patterns and helpers.