Frozen promise in a unit test

Question

I have hit a strange thing when trying to test a service returning ordinary $q promise. No promise I try in any test is actually being ever resolved/rejected (more specifically handlers from then are not called, code inside promise runs just fine). I even tried forcing digest on a root scope, as some other answers on SO suggested, without any luck.

Here is a small self-contained example:

describe('promise', function(){
  jasmine.DEFAULT_TIMEOUT_INTERVAL = 500;
  let q;

  beforeEach(inject(function($q){
    q = $q;
  }));

  it('finishes', function(done){
    expect(q).toBeDefined();
    const promise = q.resolve();
    console.log(promise);
    promise.then(
      () => done(),
      () => done.fail()
    );
  });
});

What do I have to do to get the promise work as expected?

Answer 1

You need to use $scope.$apply() (or $rootScope.$digest()) and define then() before calling it. I've modified your example:

describe('promise', function(){
  jasmine.DEFAULT_TIMEOUT_INTERVAL = 500;
  let q;
  let scope;

  beforeEach(inject(function($q, $rootScope){
    q = $q;
    scope = $rootScope.$new();
  }));

  it('finishes', function(done){
    expect(q).toBeDefined();
    const promise = q.resolve();
    promise.then(
      () => done(),
      () => done.fail()
    );
    scope.$apply();
  });
});