sails.js + mocha + supertest + sinon: how to stub

Question

I am trying to stub a sails controller function, but I don't know which object to stub. using sinon.stub(object,'funcname', function()...

This is probably related to the way sails bind controller functions...

Here is some code to give example

Controller file api/controllers/PersonController.js

var fs = require('fs');

//
// I want to stub retrieveData function when testing
//
function retreiveData(cb) {
    fs.readFile('./filedata', function (err, data) {
        if (err) throw err;
        cb(data.toString());
    });
};
function showdata(req, res) {
    var stack = new Error().stack
    console.log( stack )

    retreiveData(function (data) {
        res.send(data);
    });
};
module.exports = {
  showdata: showdata,
  retreiveData: retreiveData
};

Test file:

var request = require('supertest');
var sinon = require('sinon');
describe('GET /person/showdata', function() {
    it('should return person show data', function(done) {
        //
        // here is the stub function I want to create
        //
        stub = sinon.stub(sails.middleware.controllers.person, 'retreivedata', function(cb) {
          cb("Some stub data");
        });
        request(server)
            .get('/person/showdata')
            .expect(200)
            .expect(/Some stub data/)
            .end(function(err, res) {
                if (err)
                    throw err;
                done();
            });
    });
});

bootstrap file: test/bootstarp.test.js

var Sails = require('sails'), sails;
var _ = require('lodash');
before(function(done) {
  Sails.lift({
    // configuration for testing purposes
  }, function(err, s) {
    if (err) return done(err);
    sails = s;
    global.server = sails.hooks.http.app;
    // here you can load fixtures, etc.
    done(err, sails);
  });
});
after(function(done) {
  // here you can clear fixtures, etc.
  sails.lower(done);
});

I am running test with:

NODE_ENV=test mocha test/bootstrap.test.js test/api/**/*.js

and get :

TypeError: Attempted to wrap object property retreivedata as function

Answer 1

Here is a possible solution.

• Controller call the function from a ctrlFunc object

  var ctrlFunc = {
     retreiveData: retreiveData,
  };
  function showdata(req, res) {
          ctrlFunc.retreiveData(function (data) {
          res.send(data);
      });
  };
  

• Controller need to export ctrlFunc object during test (sinon.stub need access to ctrlFunc)

  /*
    Only add extra exports during test
    this allow sinon.stub to retreive object during test
  */
  
  if (process.env.NODE_ENV === 'test') {
      module.exports.ctrlFunc = ctrlFunc;
  }
  

• test file require PersonController, then stub method on PersonController.ctrlFunc object

      var PersonCtrl = require('../../../api/controllers/PersonController');
      stub = sinon.stub(PersonCtrl.ctrlFunc, 'retreiveData', function(cb) {
        console.log('into stub function');
        cb("Some stub data");
      });
  

placing all together we have now:

• controller file

  // File: api/controllers/PersonController.js
  var fs = require('fs');
  var ctrlFunc = {
      retreiveData: retreiveData,
  };
  function retreiveData (cb) {
      fs.readFile('./filedata', function (err, data) {
          if (err) throw err;
          cb(data.toString());
      });
  };
  
  function showdata(req, res) {
          ctrlFunc.retreiveData(function (data) {
          res.send(data);
      });
  };
  
  module.exports = {
    showdata: showdata,
  };
  
  /*
    Only add extra exports during test
    this allow sinon.stub to retreive object during test
  */
  
  if (process.env.NODE_ENV === 'test') {
      module.exports.ctrlFunc = ctrlFunc;
  }
  

• test file:

  // test/api/controllers/PersonController.test.js
  var request = require('supertest');
  var sinon = require('sinon');
  
  describe('GET /person/showdata', function() {
      var stub;
      before(function() {
          var PersonCtrl = require('../../../api/controllers/PersonController');
          stub = sinon.stub(PersonCtrl.ctrlFunc, 'retreiveData', function(cb) {
            console.log('into stub function');
            cb("Some stub data");
          });
  
      });
      after(function() {
          stub.restore();
      });
      it('should return person show data', function(done) { 
          request(server)
              .get('/person/showdata')
              .expect(200)
              .expect(/Some stub data/)
              .end(function(err, res) {
                  if (err)
                      throw err;
                  done();
              });
      });
  });
  

• test is now successfull

  NODE_ENV=test mocha test/bootstrap.test.js test/api/controllers/PersonController.test.js
      GET /person/showdata
      into stub function
          ✓ should return person show data (62ms)
        1 passing (2s)