sequbus

README

sequbus

sequbus is a generic and lightweight sequential command bus for Go. It allows you to register and execute a series of commands in a strict order. Inspired by middleware and pipeline patterns.

✨ Features

• ✅ Generic: works with any data type
• ✅ Sequential: commands run one after another
• ✅ Chainable: register multiple commands easily
• ✅ Early exit on error
• ✅ Simple interface

📦 Installation

go get github.com/go-nop/sequbus

🚀 Usage

1. Define Your Data and Command(s)

type User struct {
	ID   string
	Name string
}

type ValidateUser struct{}

func (v ValidateUser) Run(ctx context.Context, user *User) error {
	if user.ID == "" {
		return errors.New("missing ID")
	}
	return nil
}

2. Register Commands to the Bus

bus := sequbus.New[*User]()
bus.Register(ValidateUser{})
// bus.Register(SendWelcomeEmail{}) // More commands

user := &User{ID: "123", Name: "Alice"}
err := bus.Dispatch(context.Background(), user)
if err != nil {
	log.Fatal(err)
}

🧪 Testing

Run all tests:

go test ./...

📂 Project Structure

sequbus/
├── bus.go                 // CommandBus implementation
├── bus_test.go         // Unit tests
├── node.go              // Command node implementation
├── node_test.go      // Unit tests
├── runner/
    └── interface.go   // runner.Interface definition
└── example/
	└── main.go     // Example usage

📘 Interface

type Interface[T any] interface {
	Run(ctx context.Context, data T) error
}

Implement this interface to create custom commands.

---

🛠 Example Use Cases

• User registration pipeline
• Data processing workflows
• Approval chains
• Middleware-like systems in CLI or microservices

📄 License

MIT

---

Made with ❤️ by @go-nop

Documentation

Index

• type CommandBus
  • func New[T any]() *CommandBus[T]
  • func (cb *CommandBus[T]) Dispatch(ctx context.Context, data T) error
  • func (cb *CommandBus[T]) Register(r runner.Interface[T])

Types

type CommandBus

type CommandBus[T any] struct {
	// contains filtered or unexported fields
}

CommandBus is a sequential command bus that allows registering commands

func New

func New[T any]() *CommandBus[T]

New creates a new instance of CommandBus

func (*CommandBus[T]) Dispatch

func (cb *CommandBus[T]) Dispatch(ctx context.Context, data T) error

Dispatch executes the registered commands in sequence

func (*CommandBus[T]) Register

func (cb *CommandBus[T]) Register(r runner.Interface[T])

Register adds a new command to the bus