Applying SOLID Principles in JavaScript and TypeScript Framework

The article applies the SOLID principles to JavaScript and TypeScript frameworks such as React and Angular. It uses anti-patterns and refactors to show how code can be split by responsibility, extended without modifying core logic, and decoupled through abstractions.

Reading notes

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• SRP appears when components, services or classes accumulate UI, business logic, data updates and notifications; the solution presented separates these tasks into a hook, component and specific service.
• OCP is shown in validation functions and notification services, with the idea of adding rules or new types through new implementations without altering the central code.
• LSP is illustrated with button and link components in React and with Rectangle and Square in TypeScript; the proposal is to maintain safe substitution and consistent behavior among related types.
• ISP is applied when components receive too many props or when an interface forces a class to implement a method it does not use; the text proposes dividing interfaces and smaller components.
• DIP is presented as dependence on abstractions instead of concrete implementations, both by injecting functions in React and by interfaces in Angular.
• The closing encourages practice, team review and exploration of patterns such as MVC, MVVM and CQRS to carry these principles forward.