Using Sinon to stub Mongoose calls and return Promise

Using Sinon to stub Mongoose calls and return Promise

Suppose we have a schema as follows

var User = require('./schemas/UserSchema').User;

and we want to write unit test for like bellow code:

var getUserById = function () {
  return User.findOne({_id: '001'}).exec();
};

Before writing unit test we can mock the data in the following way:

var user = {
  _id: '001',
  username: 'user-001'
};

var mockFindOne = {
     exec: function () {
        return Promise.resolve(user);
    }
};

var userFindOneStub = sinon.stub(User, "findOne", function(conditions) {
    if (conditions['_id'] === '001') {
        return mockFindOne;
    }
});


This is the sample example to start writing unit test..........

sinon stub has been removed