Sinon Stub depedent class in node.js module - node.js

Question

I have one class as below
nx-user.js
class NXUser {
constructor() {}
view(guid, data) {
//do something
}
}
Then I have user controller module as below which has dependency of NxUser class
userController.js
const userDb = new NXUser();
import NXUser from "../../../persistence/nx-user";
const allUsers = () => {
return userDb.view()
}
export {allUsers }
I have below code written for stubbing view function of NxUser class for controller unit tests. But its not working. It always calling actual one instated of stubbed one
userController-test.js
let userdb=NXUser();
describe("user controller", function () {
let stubValue = [{
"name": "Urvashi Parmar",
"email": "urvashi.parmar#nationalexpress.com"]}
it("Should create user", () => {
sinon.stub(userdb, 'create').resolves(stubValue);
userController.allUsers ().then((body) => {
expect(body[0].name).to.equal(stubValue .name);
done();
});
})
}

Answer 1

Because I can not comment yet, so I need to give full answer.
Confusion: at your userController-test.js, you are trying to test NXUser.create, while at file nx-user.js has no definition of create.
Assume: you are trying to test NXUser.view.
This example is created based on your code, and is working fine. Console log "Called" will not get called.
Highlight:
Stub NXUser view directly, not userdb.create;
I use async-await inside test.
const sinon = require('sinon');
const { expect } = require('chai');
class NXUser {
constructor() {}
view(guid, data) {
console.log('Called');
return new Promise((resolve) => resolve([]));
}
// Add this only for dummy.
create() {
return new Promise((resolve) => resolve([]));
}
}
const userController = {
allUsers() {
const userDb = new NXUser();
return userDb.view();
}
}
describe('user controller', function () {
// Suppose you test view user.
it('should view user', async function () {
const stubValue = [{
name: 'Urvashi Parmar',
email: 'urvashi.parmar#nationalexpress.com'
}];
// Suppose you stub method view and not create.
const stubUserDBView = sinon.stub(NXUser.prototype, 'view');
stubUserDBView.resolves(stubValue);
const body = await userController.allUsers();
expect(body).to.be.an('array').that.have.lengthOf(1);
expect(body[0]).to.have.property('name', stubValue[0].name);
// Restore stub.
stubUserDBView.restore();
});
});
$ npx mocha stackoverflow.js
user controller
✓ should view user
1 passing (11ms)
$
Hope this helps.