Suggest how to write this more compact

Question

Many equal properties names in this code. Is it possible to make it a lot compact ?

constructor(product) {
    this.session = SessionBuilder.create();
    this.id = product.id;
    this.name = product.name;
    this.root = product.root;
    this.pics = product.pics;
    this.sizes = product.sizes;
    this.colors = product.colors;
    this.rating = product.rating;
    this.feedbacks = product.feedbacks;
}

I found only one solution with getters.

constructor(product) {
    this.session = SessionBuilder.create();
    this.product = product;
}

get id() {
    return this.product.id;
}

get name() {
    return this.product.name;
}

...

But i don't really like it. It looks better (for me), but code would be a lot more... Can someone suggest a better solution?

Answer 1

You could use a table-driven approach to safely copy only a known set of properties without having to name the properties more than once:

const propNames = ["id", "name", "root", "pics", "sizes", "colors", "rating", "feedbacks"];

class Whatever {
    
    constructor(product) {
        this.session = SessionBuilder.create();
        for (let prop of propNames) {
            this[prop] = product[prop];
        }
    }
    ...
}

---

If you just want to copy all properties from the product variable, you can use Object.assign():

class Whatever {
    
    constructor(product) {
        this.session = SessionBuilder.create();
        Object.assign(this, product);
    }
    ...
}

But, this is less safe as people could put anything in the product object, including things that might even override your own methods or properties besides the once you intended.

---

You can see solutions using object destructuring assignment here in this question: Is it possible to destructure onto an existing object?, but I didn't see any solutions there that are simpler than these.