lsp.js

/**
 * Liskov Substitution Principle (LSP): Objects of a superclass should be 
 * replaceable with objects of a subclass without affecting the 
 * correctness of the program.
 */
class Bird {
    fly() {
        console.log('I can fly');
    }
}

class Penguin extends Bird { // penguin is-a bird
    fly() {
        throw new Error('I cannot fly');
    }
}

function makeBirdFly(bird) {
    bird.fly();
}
const bird = new Bird();
const penguin = new Penguin();
makeBirdFly(bird); // I can fly
makeBirdFly(penguin); // I cannot fly

// ----
// Good Practice

class Bird {
    move() {}
}
  
class FlyingBird extends Bird { // flying bird is-a bird
    move() {
        console.log('I can fly');
    }
}
  
class NonFlyingBird extends Bird { // non-flying bird is-a bird
    move() {
        console.log('The bird walks');
    }
}
  
function makeBirdMove(bird) {
    bird.move();
}

const sparrow = new FlyingBird();
const penguin = new NonFlyingBird();
makeBirdMove(sparrow);  // The bird flies
makeBirdMove(penguin);  // The bird walks