Stubbing ES6 prototype methods using sinon

Question

I am having a problem stubbing the prototype methods of the super class using Sinon. In the example below I am stubbing the call to super class method GetMyDetails as follows. I am sure there is a better way.

actor = sinon.stub(student.__proto__.__proto__,"GetMyDetails");

And also the value of this.Role ends up being undefined.

I have created a simple class in javascript

"use strict";
class Actor {
constructor(userName, role) {
    this.UserName = userName;
    this.Role = role;
}

GetMyDetails(query,projection,populate,callback) {
    let dal = dalFactory.createDAL(this.Role);
    dal.PromiseFindOneWithProjectionAndPopulate(query, projection, populate).then(function (data) {
        callback(null,data);
    }).catch(function (error) {
        routesLogger.logError(this.Role, "GetMyDetails", error);
        return callback(error);
    })

}
}
 module.exports = Actor;

Now I have a child class that extends Actor.js

"use strict";
 class student extends Actor{
constructor(username, role) {
    super(username, role);
    this.UserName = username;       
    this.Role = role;
}

GetMyDetails(callback) {
    let query = {'username': this.UserName};
    let projection = {};
    let populateQuery = {}

    super.GetMyDetails(query, projection, populateQuery, function (err, result) {
        if (err) {
            routesLogger.logError(this.Role, "GetMyDetails", err);
            callback(err, null);
        }
        else
            callback(null, result);
    });
}

}

I have tried to create a test case for this using mocha

describe("Test Suite For Getting My Details",function(){

let request;
let response;
let actor;


beforeEach(function () {
    request = {
        session: {
            user: {
                email: '[email protected]',
                role: 'student'
            }
        },
        originalUrl:'/apssdc'
    };
    response = httpMocks.createResponse();

});

afterEach(function () {

});



it("Should get details of the student",function(done){
    let username = "student";
    let role = "Student";
    let student = new Student(username,role);
    actor = sinon.stub(student.__proto__.__proto__,"GetMyDetails");
    actor.yields(new Error(), null);

    sc.GetMyDetails(function(err,data){
        console.log(data);
        console.log(err);
    });
    done();
});
});

Answer 1

Prototype methods should be stubbed/spied directly on the prototype:

sinon.stub(Actor.prototype,"GetMyDetails");