ES6 private members are unusable if class extends "InstrumentationBase"

[Lodin]

What happened?

I want to use ES6 private members in the class that extends InstrumentationBase. However, I cannot use them in the overridden enable method in the config because the super constructor calls it beforehand, and the call fails.

Steps to Reproduce

class Foo extends InstrumentationBase {
  constructor(config: InstrumentationConfig = {}) {
    super('foo', '0.1.0', config);
  }

  override enable() {
    this.#bar();
  }

  #bar() {
    console.log('bar');
  }
}

const foo = new Foo();

Expected Result

The bar string is printed in the console.

Actual Result

Fails with the error:

Uncaught TypeError: Receiver must be an instance of class Foo

OpenTelemetry Setup Code

No response

package.json

No response

Relevant log output

No response

[Flarna]

This might be the same/similar as #1989

[MSNev]

This is because the base class is calling the function (which is not a unique issue to TypeScript / JavaScript).

For this particular issue (overriding enable) you could call the super with the config configured to specify that it's not enabled, then call this.enable yourself, making sure that your override also calls the super.enable() in the process.

[Lodin]

@MSNev, yeah, it looks like the best option. Thanks.

Please, feel free to close the ticket.