Clean Architecture

• Created by Robert Martin (Uncle Bob)
• Similar to onion and hexagonal
• Domain (real) must be decoupled from Infrastructure (code)
• The code must be the most similar to the real world

• Domain: business rules
• Application: use cases
• Infrastructure: web server, database

Characteristics

• Isolate code from application domain
• Dependency Inversion Principle (DIP)
• the rules interact with the domain
• use of interfaces
• Object Oriented Programming (OOP)
• Testability: 100% coverage on domain layer
• Independent of frameworks and infrastructure details

Definitions

• Entity: classes that have an unique id. E.g. person with cpf
• Value Object: If 2 objects have the same attribute values, they are the same. E.g., email

const p1 = { x: 2, y: 3 };
const p2 = { x: 2, y: 3 };
assert(p1 !== p2); // NOT what I want

• Factory: A class that builds other objects. It must have a .build() methods that returns the newly created object
• Repository: Represents a source of data
• Service: Represents a class that executes some action that does not belong to an entity
• Use Case: Use Cases, Application Service or Command Handler are entrypoints for the application independent of the interface (web, cli, etc)
• Repository
• Source of data interface between application and infrastructure layers
• The domain contains the interface, the infrastructure contains the implementation
• Dependency Inversion by means of interfaces