SOLID Principles in JavaScript

Which SOLID principle is demonstrated in this event handling system?

interface EventHandler {
  handle(event: Event): void;
}

class LogEventHandler implements EventHandler {
  handle(event: Event) {
    console.log(event);
  }
}

class EmailEventHandler implements EventHandler {
  handle(event: Event) {
    // Send email
  }
}

class EventProcessor {
  constructor(private handler: EventHandler) {}

  processEvent(event: Event) {
    this.handler.handle(event);
  }
}

Single Responsibility Principle
Interface Segregation Principle
Dependency Inversion Principle
This code demonstrates the Dependency Inversion Principle (DIP). The EventProcessor depends on the EventHandler abstraction rather than concrete implementations. This allows for different types of event handlers to be injected, making the system flexible and extensible. Both high-level (EventProcessor) and low-level (specific handlers) modules depend on the abstraction (EventHandler interface).
Open/Closed Principle

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