teamai-test/.teamai/skills/common/golang-dependency-injection/references/samber-do.md

samber/do — Generics-Based DI

For the full samber/do API, patterns, and advanced features, see the samber/cc-skills-golang@golang-samber-do skill.

Type-safe dependency injection using Go generics. No reflection, no code generation, simple API.

• Docs: do.samber.dev | github.com/samber/do/v2

Core Pattern

// Register services with providers
injector := do.New()
do.Provide(injector, func(i do.Injector) (*UserService, error) {
    db := do.MustInvoke[*Database](i)
    return NewUserService(db), nil
})

// Invoke services (lazy — created on demand)
svc := do.MustInvoke[*UserService](injector)

// Graceful shutdown — all services implementing Shutdowner are closed
injector.ShutdownOnSignalsWithContext(ctx, os.Interrupt)

Why samber/do

• No code generation — no build step, no generated files to maintain
• No reflection — errors are caught at compile time via generics, not at runtime
• Strongly typed — Go generics provide full type safety without interface{} casts
• Built-in lifecycle — health checks and graceful shutdown detected automatically
• Container cloning — create isolated test containers from production configuration
• Simple API — Provide, Invoke, Shutdown — that's most of what you need
• Package system — organize services by domain without manual wiring order

→ See samber/cc-skills-golang@golang-samber-do for full application setup, package organization, lifecycle management, debugging, testing with clone + override, and complete API reference.