Question

I started to use JUnit and Mockito in my projects, what I have noticed quickly is I ended up converting my private methods to public in order to be accesed from test classes, which is a terrible solution.

Sometimes it is sufficient to test only the public methods, but sometimes i want to really test some internal methods as well. Is there a workaround for this? for example a special annotation that allows JUnit to mock a private method as public or something like that?

Answer 1

Your public methods must be calling your private methods.
So you can test your private method by making a test function of your public method.

If you still want to test private function by Junits, you can do it by using reflection.

You have to set the property of method setAccessible==true.

Example:

 public void testisvalid() throws Exception 
    {
        MyHandler handler = new MyHandler();
        Method privateStringMethod = MyHandler.class.getDeclaredMethod("isvalid", Long.class);
        privateStringMethod.setAccessible(true);
        String =  (String) privateStringMethod.invoke(handler, 852l );
        assertNotNull(s);
    }

In the getDeclaredMethod you have to give the name of the private method , and the type of the arguments you are passing in the function in order.