Native Class Inheritance Issue

[cbratschi]

• Version: v6.9.1
• Platform: macOS (Darwin)
• Subsystem: v8

A native v8 class is extended on the JavaScript side and new methods are added. However, those methods cannot be called in the newly created instance: they are undefined. Something seems to be wrong with the prototype chain. It also fails if the older prototyping syntax is being used.

The issue is reproducible on Node.js v.6.9.1. Node v4.x and v7.0.0 are not affected.

Sample code:

https://github.com/cbratschi/aminogfx-gl/blob/master/demos/tests/js.js

/**
 * Extend AminoGfx Class.
 */
class Circle extends Polygon {
   constructor(amino) {
       super(amino);

       console.log('Circle: constructor');

       /*
        * Issues:
        *
        *   - Node v6.9.1
        *     - TypeError: this.setup is not a function
        *
        * Works fine:
        *
        *   - Node v4.x
        *   - Node v7.0.0
        */
       this.setup();
   }

   setup() {
       console.log('Circle.setup()');
   }
}

Polygon is the native class.

[addaleax]

This seems to be a duplicate of #9288. You can subscribe to that thread and #9293 (the PR that would fix this in v6.x, if it works at some point) to stay up to date.

I’m closing this as a duplicate but feel free to ask follow-up questions if there are any.