Refactor(back): Add An Auth Service Agnostic From Provider

Introduction

In software development, it's essential to maintain a clean and modular architecture to ensure scalability, maintainability, and flexibility. One way to achieve this is by introducing an abstraction layer that decouples dependent components from specific implementation details. In the context of authentication, this means creating an interface that defines the required functionality without specifying how it should be implemented. In this article, we'll explore how to refactor the authentication service in our application to make it provider-agnostic.

Current Implementation

Currently, we're using functions directly in the ZenaoServer object to interact with the authentication provider. This approach has several drawbacks:

• Tight Coupling: The ZenaoServer object is tightly coupled with the authentication provider, making it difficult to switch to a different provider or modify the existing implementation.
• Limited Flexibility: The direct function calls limit our ability to add new authentication providers or modify the existing ones without affecting the rest of the application.

Introducing the Auth Interface

To address these issues, we'll introduce an Auth interface that defines the required functionality without specifying how it should be implemented. This interface will serve as a contract between the ZenaoServer object and the authentication provider.

type Auth interface {
    GetUser              func(ctx context.Context) *zeni.AuthUser
    GetUsersFromIDs func(ctx context.Context, ids []string) ([]*zeni.AuthUser, error)
    CreateUser           func(ctx context.Context, email string) (*zeni.AuthUser, error)
}

The Auth interface defines three methods:

• GetUser: Retrieves a user's authentication information.
• GetUsersFromIDs: Retrieves a list of users' authentication information based on their IDs.
• CreateUser: Creates a new user with the provided email address.

Implementing the Clerk Auth Provider

To demonstrate the usage of the Auth interface, we'll implement a Clerk authentication provider in a separate package called czauth. This package will contain the implementation of the Auth interface using the Clerk API.

// czauth/czauth.go
package czauth

import (
    "context"
    "github.com/your-project/zenao/zeni"
    "github.com/your-project/zenao/auth"
)

type ClerkAuth struct{}

func (ca *ClerkAuth) GetUser(ctx context.Context) *zeni.AuthUser {
    // Implement Clerk API call to retrieve user information
}

func (ca *ClerkAuth) GetUsersFromIDs(ctx context.Context, ids []string) ([]*zeni.AuthUser, error) {
    // Implement Clerk API call to retrieve users' information
}

func (ca *ClerkAuth) CreateUser(ctx context.Context, email string) (*zeni.AuthUser, error) {
    // Implement Clerk API call to create a new user
}

func NewClerkAuth() auth.Auth {
    return &ClerkAuth{}
}

Using the Auth Interface in ZenaoServer

To use the Auth interface in the ZenaoServer object, we'll inject an instance of the Auth interface through the constructor. This allows us to switch between different authentication providers without modifying the ZenaoServer` object.

// zenao/zenao_server.go
package zenao

import (
    "context"
    "github.com/your-project/zenao/auth"
)

type ZenaoServer struct {
    auth auth.Auth
}

func NewZenaoServer(auth auth.Auth) *ZenaoServer {
    return &ZenaoServer{auth: auth}
}

func (zs *ZenaoServer) GetUser(ctx context.Context) *zeni.AuthUser {
    return zs.auth.GetUser(ctx)
}

func (zs *ZenaoServer) GetUsersFromIDs(ctx context.Context, ids []string) ([]*zeni.AuthUser, error) {
    return zs.auth.GetUsersFromIDs(ctx, ids)
}

func (zs *ZenaoServer) CreateUser(ctx context.Context, email string) (*zeni.AuthUser, error) {
    return zs.auth.CreateUser(ctx, email)
}

Benefits of the Refactored Implementation

The refactored implementation provides several benefits:

• Decoupling: The ZenaoServer object is decoupled from the authentication provider, making it easier to switch between different providers or modify the existing implementation.
• Flexibility: The Auth interface allows us to add new authentication providers or modify the existing ones without affecting the rest of the application.
• Testability: The Auth interface makes it easier to test the ZenaoServer object in isolation, as we can mock the authentication provider's behavior.

Conclusion

Introduction

In our previous article, we refactored the authentication service in our application to make it provider-agnostic. We introduced an Auth interface that defines the required functionality without specifying how it should be implemented. In this article, we'll answer some frequently asked questions about the refactored implementation.

Q: Why do we need an Auth interface?

A: The Auth interface provides a contract between the ZenaoServer object and the authentication provider. It decouples the ZenaoServer object from the authentication provider, making it easier to switch between different providers or modify the existing implementation.

Q: How does the Auth interface improve testability?

A: The Auth interface makes it easier to test the ZenaoServer object in isolation, as we can mock the authentication provider's behavior. This improves testability and reduces the complexity of testing the ZenaoServer object.

Q: Can we add new authentication providers using the Auth interface?

A: Yes, we can add new authentication providers using the Auth interface. We simply need to implement the Auth interface for the new provider and register it with the ZenaoServer object.

Q: How do we switch between different authentication providers?

A: To switch between different authentication providers, we simply need to change the instance of the Auth interface passed to the ZenaoServer object. This allows us to switch between different providers without modifying the ZenaoServer object.

Q: What are the benefits of using the Auth interface?

A: The benefits of using the Auth interface include:

• Decoupling: The ZenaoServer object is decoupled from the authentication provider, making it easier to switch between different providers or modify the existing implementation.
• Flexibility: The Auth interface allows us to add new authentication providers or modify the existing ones without affecting the rest of the application.
• Testability: The Auth interface makes it easier to test the ZenaoServer object in isolation, as we can mock the authentication provider's behavior.

Q: How does the Auth interface relate to the Clerk authentication provider?

A: The Auth interface is used to implement the Clerk authentication provider. We've created a package called czauth that contains the implementation of the Auth interface using the Clerk API.

Q: Can we use the Auth interface with other authentication providers?

A: Yes, we can use the Auth interface with other authentication providers. We simply need to implement the Auth interface for the new provider and register it with the ZenaoServer object.

Conclusion

In this article, we've answered some frequently asked questions about the refactored implementation of the authentication service in our application. We've discussed the benefits of using the Auth interface, including decoupling, flexibility, and testability. We've also covered how to switch between different authentication providers and how the Auth interface relates to the Clerk authentication provider.