How do I get descriptor for JavaScript class constructor function?

Is it possible for me to get the descriptor for the actual constructor method of a JS class? I am writing my own little wrapper around Express to try and procedurally generate routes and stuff (and I am sure there are plenty of other libraries to do this, but it’s a learning experience).

If I iterate through the function descriptors for a class prototype, I can convert the ‘value’ property to a string that represents a single method. If I call getString() on the descriptor for ‘constructor’ I get the entire class. I ONLY want the body of the constructor. I could add more parsing logic, but there has to be a way to do this.

Here is a simple controller:

const
    BaseController = require('../src/baseController');

/**
 * Handle requests for the home page
 */
class HomeController extends BaseController {
    /**
     * @param settings Controller settings
     * @param vault Injected vault client
     */
    constructor(settings, vault) {
        super(settings);
        this.vault = vault;
    }

    /**
     * Serve the landing page
     * @returns 
     */
    async get() {
        await this.renderAsync({ pageTitle: 'Pechanga Demo' });
    }
}

module.exports = HomeController;

Here is what currently comes back for ‘get’:

Object.getOwnPropertyDescriptor(controllerType.prototype, 'get').value.toString()

async get() {
   await this.renderAsync('index', { pageTitle: 'Pechanga Demo' });
}

However, getting the descriptor for ‘constructor’ returns the entire class body:

Object.getOwnPropertyDescriptor(controllerType.prototype, 'constructor').value.toString()

I really want is just:

    constructor(settings, vault) {
        super(settings);
        this.vault = vault;
    }

Is this possible without parsing the entire class body?