PART 1 — DESIGN PRINCIPLES - SOLID

The SOLID principles tell us how to arrange our functions and data structures into classes, and how those classes should be interconnected. The use of the word “class” not imply that these principles are applicable only to object-oriented software class is simply a coupled grouping of functions and data. Every software system has such groupings, whether they are called classes or not. The SOLID principles apply to those groupings.The goal of the principles is the creation of mid-level software structures that:

• Tolerate change,
• Are easy to understand, and
• Are the basis of components that can be used in many software systems.

In the next posts we will describe in more detail and put into practice in a node js project.

Here they are summary:

• SRP: The Single Responsibility Principle
  An active corollary of Conway’s law: the best structure for a software system is heavily influenced by the social structure of the organization that uses it so that each software module has one, and only one, reason to change
• OCP: the open-closed principle
  Bertrand Meyer made this principle famous in the 1980s. The essence is that for software systems to be easy to change, they must be designed to allow the behavior of these systems to be changed by adding new code, instead of changing the existing ones code.
• LSP: The Liskov Substitution Principle
  Barbara Liskov’s famous definition of subtypes, from 1988. In short, this principle says that to build software systems from interchangeable parts, those parts must adhere to a contract that allows those parts to be substituted one for another.
• ISP: The Interface Segregation Principle
  This principle advises software designers to avoid depending on things that they don’t use
• DIP: The Dependency Inversion Principle
  The code that implements high-level policy should not depend on the code that implements low-level details. Rather, details should depend on policies.