Stubbing the mongoose save method on a model

Question

I would like to stub the save method available to Mongoose models. Here\'s a sample model:

/* model.js */
var mongoose = require(\'mongoose\');
         


        

Answer 1

Here's the final configuration I developed, which uses a combination of sinon and mockery:

// Dependencies
var expect = require('chai').expect;
var sinon = require('sinon');
var mockery = require('mockery');
var reloadStub = require('../../../spec/utils/reloadStub');

describe('UNIT: userController.js', function() {

  var reportErrorStub;
  var controller;
  var userModel;

  before(function() {
    // mock the error reporter
    mockery.enable({
      warnOnReplace: false,
      warnOnUnregistered: false,
      useCleanCache: true
    });

    // load controller and model
    controller = require('./userController');
    userModel = require('./userModel');
  });

  after(function() {
    // disable mock after tests complete
    mockery.disable();
  });

  describe('#createUser', function() {
    var req;
    var res;
    var status;
    var end;
    var json;

    // Stub `#save` for all these tests
    before(function() {
      sinon.stub(userModel.prototype, 'save');
    });

    // Stub out req and res
    beforeEach(function() {
      req = {
        body: {
          username: 'Andrew',
          userID: 1
        }
      };

      status = sinon.stub();
      end = sinon.stub();
      json = sinon.stub();

      res = { status: status.returns({ end: end, json: json }) };
    });

    // Reset call count after each test
    afterEach(function() {
      userModel.prototype.save.reset();
    });

    // Restore after all tests finish
    after(function() {
      userModel.prototype.save.restore();
    });

    it('should call `User.save`', function(done) {
      controller.createUser(req, res);
      /**
       * Since Mongoose's `new` is asynchronous, run our expectations on the
       * next cycle of the event loop.
       */
      setTimeout(function() {
        expect(userModel.prototype.save.callCount).to.equal(1);
        done();
      }, 0);
    });
  }
}

Answer 2

Have you tried:

sinon.stub(userModel.prototype, 'save')

Also, where is the helper function getting called in the test? It looks like you define the function as the utils module, but call it as a method of a controller object. I'm assuming this has nothing to do with that error message, but it did make it harder to figure out when and where the stub was getting called.