Comparison with Other DI Solutions

This guide compares godi with other dependency injection solutions in the Go ecosystem, helping you choose the right tool for your project.

Comparison Table

Feature	godi	wire	fx	dig	Manual DI
Type Safety	✅ Compile-time with generics	✅ Code generation	✅ Runtime	✅ Runtime	✅ Compile-time
Runtime/Compile	Runtime	Compile-time	Runtime	Runtime	Manual
Scoped Lifetimes	✅ Full support	❌ No	✅ Via modules	❌ No	Manual
Service Lifetimes	Singleton, Scoped, Transient	Singleton only	Singleton	Singleton	Manual
Learning Curve	Low (familiar API)	Medium	High	Medium	Low
Boilerplate	Minimal	Some	Moderate	Minimal	High
Testing	Excellent	Good	Good	Good	Depends
Performance	Good	Excellent	Good	Good	Excellent
Microsoft DI Style	✅ Yes	❌ No	❌ No	❌ No	❌ No

Detailed Comparisons

godi vs wire (Google)

Wire uses code generation to create dependency injection code at compile time.

// Wire
//+build wireinject

func InitializeApp() (*App, error) {
    wire.Build(NewConfig, NewDatabase, NewService, NewApp)
    return nil, nil // Wire will generate this
}

// godi
services := godi.NewServiceCollection()
services.AddSingleton(NewConfig)
services.AddSingleton(NewDatabase)
services.AddScoped(NewService)
services.AddScoped(NewApp)

provider, _ := services.BuildServiceProvider()
app, _ := godi.Resolve[*App](provider)

Key Differences:

• Wire generates code at compile time (faster runtime)

• godi resolves at runtime (more flexible)

• Wire requires build tags and code generation step

• godi works without any build tools

• Wire only supports singleton lifetime

• godi supports singleton, scoped, and transient lifetimes

When to use Wire:

• You want zero runtime overhead

• You prefer compile-time verification

• You don’t need scoped services

• You’re okay with code generation

When to use godi:

• You need scoped services (e.g., for web requests)

• You want Microsoft-style DI

• You prefer runtime flexibility

• You want to avoid code generation

godi vs fx (Uber)

Fx is a full application framework with dependency injection.

// Fx
app := fx.New(
    fx.Provide(
        NewConfig,
        NewDatabase,
        NewService,
        NewHTTPServer,
    ),
    fx.Invoke(func(*http.Server) {}),
)
app.Run()

// godi
services := godi.NewServiceCollection()
services.AddSingleton(NewConfig)
services.AddSingleton(NewDatabase)
services.AddScoped(NewService)
services.AddSingleton(NewHTTPServer)

provider, _ := services.BuildServiceProvider()
server, _ := godi.Resolve[*http.Server](provider)
server.ListenAndServe()

Key Differences:

• Fx is a full framework with lifecycle management

• godi is just dependency injection

• Fx has built-in app lifecycle (start/stop hooks)

• godi requires manual lifecycle management

• Fx has a steeper learning curve

• godi has familiar API (especially for .NET developers)

When to use Fx:

• You want a full application framework

• You need complex lifecycle management

• You’re building microservices

• You want built-in logging and metrics

When to use godi:

• You want just dependency injection

• You prefer Microsoft-style API

• You need scoped services

• You want to keep things simple

godi vs dig (Uber)

Dig is the underlying DI container used by fx (and godi!).

// Dig
container := dig.New()
container.Provide(NewConfig)
container.Provide(NewDatabase)
container.Provide(NewService)

err := container.Invoke(func(s *Service) {
    // Use service
})

// godi
services := godi.NewServiceCollection()
services.AddSingleton(NewConfig)
services.AddSingleton(NewDatabase)
services.AddScoped(NewService)

provider, _ := services.BuildServiceProvider()
service, _ := godi.Resolve[*Service](provider)

Key Differences:

• godi is built on top of dig

• godi adds service lifetimes (scoped, transient)

• godi provides Microsoft-style API

• dig is lower level

• godi adds automatic disposal

• godi provides type-safe generics

When to use Dig:

• You want maximum control

• You only need singleton services

• You prefer minimal abstraction

• You’re building your own DI framework

When to use godi:

• You want service lifetimes

• You need scoped services

• You prefer higher-level API

• You want automatic disposal

godi vs Manual DI

Manual DI means wiring dependencies yourself.

// Manual DI
func main() {
    config := NewConfig()
    logger := NewLogger(config)
    db := NewDatabase(config, logger)
    cache := NewCache(config)
    userRepo := NewUserRepository(db, logger)
    userService := NewUserService(userRepo, cache, logger)
    handler := NewHandler(userService, logger)

    // Manual cleanup
    defer db.Close()
    defer cache.Close()

    http.ListenAndServe(":8080", handler)
}

// godi
func main() {
    services := godi.NewServiceCollection()
    services.AddSingleton(NewConfig)
    services.AddSingleton(NewLogger)
    services.AddSingleton(NewDatabase)
    services.AddSingleton(NewCache)
    services.AddScoped(NewUserRepository)
    services.AddScoped(NewUserService)
    services.AddScoped(NewHandler)

    provider, _ := services.BuildServiceProvider()
    defer provider.Close() // Automatic cleanup

    handler, _ := godi.Resolve[*Handler](provider)
    http.ListenAndServe(":8080", handler)
}

Key Differences:

• Manual requires explicit wiring

• godi wires automatically

• Manual is faster (no overhead)

• godi is more maintainable

• Manual requires manual cleanup

• godi has automatic disposal

When to use Manual DI:

• Very small applications

• Performance-critical code

• You want full control

• Simple dependency graphs

When to use godi:

• Medium to large applications

• Complex dependency graphs

• You want automatic wiring

• You need service lifetimes

Feature-by-Feature Comparison

Service Lifetimes

Framework	Singleton	Scoped	Transient
godi	✅	✅	✅
wire	✅	❌	❌
fx	✅	⚠️*	❌
dig	✅	⚠️*	❌
Manual	✅	✅	✅

* Possible with workarounds but not built-in

Developer Experience

Framework	Setup Complexity	API Familiarity	Documentation	Error Messages
godi	Low	High (.NET-like)	Good	Clear
wire	Medium	Medium	Excellent	Compile-time
fx	High	Low	Good	Detailed
dig	Low	Medium	Good	Technical
Manual	None	N/A	N/A	Your own

Testing Support

Framework	Mock Injection	Test Isolation	Setup Speed
godi	Excellent	Excellent	Fast
wire	Good	Good	Requires gen
fx	Good	Good	Moderate
dig	Good	Moderate	Fast
Manual	Depends	Depends	Fast

Use Cases

Use Case	Best Choice	Why
Web API with request scoping	godi	Built-in scoped lifetime support
CLI tool	wire	Zero runtime overhead
Microservice	fx	Full framework with lifecycle
Library	Manual	No dependencies
Enterprise app	godi	Familiar patterns, full features
Performance critical	wire	Compile-time resolution

Code Examples Side-by-Side

Basic Setup

// godi
collection := godi.NewServiceCollection()
collection.AddSingleton(NewService)
provider, _ := collection.BuildServiceProvider()

// wire
wire.Build(NewService)

// fx
fx.New(fx.Provide(NewService))

// dig
container := dig.New()
container.Provide(NewService)

// manual
service := NewService()

With Dependencies

// godi
collection.AddSingleton(NewDatabase)
collection.AddSingleton(NewLogger)
collection.AddScoped(NewUserService) // Auto-wires Database and Logger

// wire
wire.Build(NewDatabase, NewLogger, NewUserService)

// fx
fx.Provide(NewDatabase, NewLogger, NewUserService)

// dig
container.Provide(NewDatabase)
container.Provide(NewLogger)
container.Provide(NewUserService)

// manual
db := NewDatabase()
logger := NewLogger()
userService := NewUserService(db, logger)

Testing

// godi
testCollection := godi.NewServiceCollection()
testCollection.AddSingleton(func() Database { return &MockDB{} })
testCollection.AddScoped(NewUserService)

// wire
// Requires separate injector for tests

// fx
fx.New(
    fx.Provide(func() Database { return &MockDB{} }),
    fx.Provide(NewUserService),
)

// dig
container.Provide(func() Database { return &MockDB{} })
container.Provide(NewUserService)

// manual
mockDB := &MockDB{}
userService := NewUserService(mockDB, mockLogger)

Decision Matrix

Choose godi if:

• ✅ You need scoped services (web apps)

• ✅ You want Microsoft-style DI

• ✅ You prefer runtime flexibility

• ✅ You want automatic disposal

• ✅ You need transient services

• ✅ You want familiar patterns

Choose wire if:

• ✅ You want zero runtime overhead

• ✅ You prefer compile-time safety

• ✅ You only need singletons

• ✅ You’re building CLIs or tools

• ✅ You’re okay with code generation

Choose fx if:

• ✅ You want a full framework

• ✅ You need lifecycle management

• ✅ You’re building microservices

• ✅ You want built-in observability

• ✅ You need module system

Choose dig if:

• ✅ You want low-level control

• ✅ You’re building a framework

• ✅ You only need singletons

• ✅ You want minimal abstraction

Choose manual DI if:

• ✅ Your app is very small

• ✅ You have simple dependencies

• ✅ You want zero overhead

• ✅ You want full control

Migration Effort

From → To	Effort	Main Changes
Manual → godi	Low	Add service registration
wire → godi	Medium	Remove code gen, add lifetimes
fx → godi	Medium	Remove lifecycle hooks
dig → godi	Low	Add service collection
godi → wire	High	Add code gen, remove scopes
godi → fx	Medium	Add lifecycle management

Conclusion

godi fills a unique niche in the Go DI ecosystem:

• Familiar API for developers coming from .NET

• Full lifetime support including scoped and transient

• Runtime flexibility without code generation

• Built on proven foundation (Uber’s dig)

• Excellent for web applications with request scoping

Choose the right tool for your specific needs, but if you want the most feature-complete DI solution with a familiar API, godi is an excellent choice.