如何使用内部调用返回promise的函数的茉莉花节点测试函数？

Question

I am just trying out jasmine-node. I need some help with promise resolution. I have simple js file

//dataService.js

var Q = require('q');
console.info("Q is "+Q);
exports.test = function() {
    console.warn("Will call promise now");
    this.getQuestions().then(function() {
        console.log("Test..");
    });
};

exports.getQuestions = function() {

    var deferred = Q.defer();
    for(i=0; i<=10; i++) {
        if(i===10) {
            deferred.resolve(i);
        }
    }
    return deferred.promise;
    // return {
    //  'Question1': 'What is your name'
    // }
}

//end of dataService.js



And the test is

// testspec.js


var assert = require("assert");
var q = require('q');
var testFile = require('../routes/dataService');
var fs = require('fs');


  describe('#indexOf()', function(done){
    it('should return -1 when the value is not present', function(done){
        console.log("Teststststst" + fs);
      assert.equal(-1, [1,2,3].indexOf(5));
      assert.equal(-1, [1,2,3].indexOf(0));
      spyOn(testFile, 'getQuestions').andCallFake(function() {
            console.warn("Spy Called********************");
            var deferred = q.defer();
            deferred.resolve(1);
            console.info("passing 1****");  
            //done(1);
            return deferred.promise;
      });
      spyOn(console, 'log');
      testFile.test();
      console.info("Testststststsinggggggggg");
      expect(console.log).toHaveBeenCalledWith("Test..");
      console.info("Done*****************");
    })
  });

//end of test file

Now as you can see I am calling testFile.test() function which is nothing but the test function in dataService.js. This function calls the getQuestions() in the dataService.js (same file), which returns a promise. I have mocked the getQuestions() function in my test, it is getting called and is resolving the promise, but my test() success method is not getting called, so my test is failing.

Answer 1

Your getQuestions method never resolves the promise.

You have a loop running from 0 to 9 but you only resolve it if i === 10 .

Change:

for(i=0; i<10; i++) {
    if(i===10) {
        deferred.resolve(i);
    }
}

To:

deferred.resolve(10);

As a general tip methods that call functions that return promises should return promises themselves so you can easly test them and hook on their completion. For this reason I'd make .test return a promise (rather than just call it)

Answer 2

I was able to run the test by returning a promise from the test() function.


//dataService.js

var Q = require('q');
console.info("Q is "+Q);
exports.test = function() {
    console.warn("Will call promise now");
    return this.getQuestions().then(function() {
        console.log("Test..");
        return 'success';
    });

};

exports.getQuestions = function() {

    var deferred = Q.defer();
    for(i=0; i<10; i++) {
        if(i===3) {
            deferred.resolve(i);
        }
    }
    return deferred.promise;
    // return {
    //  'Question1': 'What is your name'
    // }
}

//end of dataService.js



//dataServicespec.js

var assert = require("assert");
var q = require('q');
var testFile = require('../routes/dataService');//include the dataService.js
var fs = require('fs');


describe('Tests', function(done) {
  it('should run the test properly', function(done) {
    console.log("Teststststst" + fs);
    var flag = false;
    var deferred;

    spyOn(testFile, 'getQuestions').andCallFake(function() {
      console.warn("Spy Called********************");
      deferred = q.defer();
      console.info("passing 1****");
      deferred.resolve(1);
      return deferred.promise;
    });

    spyOn(console, 'log');

    runs(function() {
      var p = testFile.test();
      p.then(function() {
        flag = true;
      });
    });

    waitsFor(function() {
      if (flag === true)
        return true;
    });

    runs(function() {
      console.info("Testststststsinggggggggg");
      expect(console.log).toHaveBeenCalledWith("Test..");
      console.info("Done*****************");
      done();
    });



  })
});

//end of dataServicespec.js


Thanx @Benjamin on you suggestion for returning a promise from test.