Angular JS单元测试：如何在不返回的服务中测试功能

Question

I'm sorry for possible duplicate, I didn't find any solution for my problem.

I'm need to write tests for a service in Angular JS app.

So I have one main function that returns and uses as an external method. And a couple help functions for external. So how can I call and test things inside help functions ( subFunc )?

service.js

function TestService() {
  return {
    mainFunc: mainFunc
  };

  funcion mainFunc() {
    //do some and call subFunc()
    subFunc(a)
  }

  function subFunc(a) {
    if (a === 1) {
      // ... magic 1
      return true;
    } else {
      // ... magic 2
      return false;
    }
  }
}
})()

service.spec.js

describe('Test Service', function() {
  beforeEach(module('TestService'));
  var TestService;

  beforeEach(inject(function($injector) {
      TestService = $injector.get('TestService');
  }));

  it('should return true if subFunc called with 1', function () {
    // ....
  });
})

Answer 1

Rewrite TestService to expose subFunc so that you can stub it with a spy and track whether it was called.

That is one of the reasons you write tests before and while writing the code: they will influence the style of the code so as to make it easier to test. In this case subFunc has to be externally visible to allow easy testing so make it visible.