JSDoc comment on JS class property isn't inherited when derived class also initializes it

Bug Report

When a JS class extends another, and members are overridden in the constructor, they will lose all of their documentation - even if they are compatible values.

🔎 Search Terms

jsdoc class es6 js extends

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about JS / JSDoc

⏯ Playground Link

Playground link with relevant code

Note the type info when hovering over this.a in Derived's constructor, or a in the bottom line.

💻 Code

class Base
{
    constructor()
    {
        /** I am an integer! */
        this.a = 100;
    }
}

class Derived extends Base
{
    constructor()
    {
        super();

        this.a = 50;

// hover over this.a above to see the issue
    }
}

// hover over a to see the issue as well
new Derived().a

🙁 Actual behavior

a was overridden by Derived, even though it is a type match.

🙂 Expected behavior

While I can see the usefulness here if a was a different/incompatible type entirely, I would rather an error occur on, for instance, this.a = "str"; because a is a number, not a string, and for it to inherit the JSDoc properly. It seems like this.xxx in a constructor declares a new variable, even if it inherits one.

Inizia con il TypeScript Playground collegato e riproduci il comportamento al passaggio del mouse su this.a in Derived e new Derived().a. Traccia come vengono interpretati i costruttori delle classi JavaScript e il commento JSDoc, quindi verifica che gli override compatibili mantengano la documentazione e che le assegnazioni incompatibili vengano diagnosticate.