Convert field initializers in constructor to class fields

[PrasannaBrabourame]

It is possible to get latest JS conversion?
For Eg : without constructor and 'this' keyword

class User {
  name = "Anonymous";
  sayHi() {
    alert(`Hello, ${this.name}!`);
  }
}

[nene]

Sorry, but I don't understand your question.

Try to formulate your question as:

• which input do you give to Lebal?
• what does Lebab output?
• which output would you expect instead?

[uniibu]

@nene I think what he meant withlatest JS conversion is like for example with Classes, it is not required to use a constructor and if left out, it will use a default constructor as stated here https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/constructor#Default_constructors

However private and public fields like the one he used name = "Anonymous" is still at stage 3 and support are still limited. https://github.com/tc39/proposal-class-fields

[PrasannaBrabourame]

@nene I am expecting the output which was stated by @uniibu

[nene]

OK. So as I understand it, given input like:

function User() {
  this.name = "Anonymous";
}
User.prototype.sayHi = function() {
  alert(`Hello, ${this.name}!`);
}

Lebab class transform currently produces:

class User {
  constructor() {
    this.name = "Anonymous";
  }

  sayHi() {
    alert(`Hello, ${this.name}!`);
  }
}

But you would instead expect to see:

class User {
  name = "Anonymous";
  sayHi() {
    alert(`Hello, ${this.name}!`);
  }
}

As @uniibu pointed out, class fields are currently a stage-3 proposal. I think it would be a nice feature to implement regardless, as the class fields feature is kinda widely used.

Unfortunately the Espree parser which Lebab uses doesn't support this syntax yet. So first we'd have to switch to another parser like Babylon. I don't think I personally have much motivation to do this. But of course pull requests are always welcome.

[frank-dspeed]

@nene espree is now acron based so it supports plugins so the syntax is supported