JS IntelliSense only picks up JSDoc @inherits rule in class definition but not on children or instances

TS Template added by @mjbvz

TypeScript Version: 4.1.0-dev.20201026

Search Terms

• jsdoc

• VSCode Version: 1.50.1
• OS Version: 18.04

Steps to Reproduce:

I apologize if this is not the correct place for this issue, I tried hard finding the repository that is responsible for js intellisense.

1. Create a new js file
2. Copy below code into the file

function Mixin1 (base) {
  return class extends base {
    foo() {}
  }
}

function Mixin2 (base) {
  return class extends base {
    bar() {}
  }
}

class IntermediateDummyClass extends Mixin1(Object) {}

/**
 * @implements {IntermediateDummyClass}
 */
class Composite extends Mixin2(IntermediateDummyClass) {
  
}

let c = new Composite;

c.

3. Observe autocomplete suggestions - within Composite class both foo and bar are suggested

However when instantiated or extended only bar is picked up.

Does this issue occur when all extensions are disabled?: Yes

Start by running the provided JavaScript reproduction in the TypeScript language service and compare IntelliSense for Composite, its instance, and an extending class. Trace how the JSDoc @implements rule is applied in the reproduction, then verify that foo and bar are suggested consistently for the class, instances, and children.