SOLID Principles of OOP

This repository contains 5 simple examples of the SOLID principles (1 example per principle) in typescript. The intention is to show how can they be applied on a practical level.

How to install and run the tests

Install dependencies:

yarn install

Run tests:

yarn test

Basic Theory

Single Responsibility Principle

Single Responsibility Principle states that a class should have only one reason to change. In other words, a class should have only one job.

Open-Closed Principle

Open-Closed Principle states that software entities should be open for extension, but closed for modification. In other words, you should be able to add new functionality without changing existing code.

Liskov Substitution Principle

Liskov Substitution Principle states that objects of a superclass shall be replaceable with objects of its subclasses without breaking the application.

Interface Segregation Principle

Interface Segregation Principle states that no class should be forced to implement methods or interfaces it does not use.

Dependency Inversion Principle

Dependency Inversion Principle states that high-level modules should not depend on low-level modules. Both should depend on abstractions. Abstractions should not depend on details, details should depend on abstractions.