验证Mockito中调用downstream的一个方法（通过private void重载方法）

Question

I'm having trouble figuring out how to test if my method foo(int length, String name) is being called.

My complications:

1. I have an overloaded void method, plus it's private (I cannot change it from private although that would work, for this purpose)
2. It has a public method downstream from the private method I could try to test (Bar.bar()), but not sure how to test it properly with Mockito
3. I'm trying to test for customer length over 5 and under 5, to make sure it hits the private foo method either once if it's over, or none if it's under. Either way, it will be hitting public foo(Customer) once.
4. Would rather not use Powermockito for simplicity if possible

 public class Foo { public void foo(Customer customer) { if (customer.length() > 5) { foo(customer.length(), customer.name()); } else { return } } //Private overloaded method private void foo(int length, String name) { bar.bar(); } } public class Bar { public Order bar(int length, String name) { barProcessing(...) } private Order barProcessing(...) {...calling another Bar method } }

What I've tried so far:

Mocking Foo and Bar classes plus doing a bunch of when() statements, then doing...

• verify(foo, times(1)).foo(any(Customer.class)); (WORKS)
• verify(bar, times(1)).bar(any(Integer.class), any(String.class)); (FAILS, returns 0)
• doCallRealMethod().when(foo).foo(any(Customer.class)); (WORKS)
• foo.foo(Customer); (WORKS)
• BDDMockito.given(bar.bar("123", date)).willReturn(Order); (FAILS)
• BDDMockito.then(bar).should().bar(any(Integer.class), any(String.class)); (FAILS)

Pretty stumped here, with the addition of my complications. I'm still new to Mockito, open to any new suggestions.

Answer 1

1. In general, test the behavior of public API. Private methods are an implementation detail; test them indirectly through calling the public methods.
2. You're on the right track with mocking bar and confirming that it's used somewhere by foo(Customer) . You said you've "tried" mocking it, but not how you actually did that. Your #2 and #6 should generally work; actually debug your code and check whether bar.bar() is really being invoked as well as whether your mock is being injected into your Foo .

Edit

After some clarification, it seems you misunderstand when to use mocks in testing. You use mocks specifically for the items that you are not testing; if you're testing Foo but then mock it, you're not testing the actual behavior, Instead, mock the Bar and provide it however you would mock a real Bar (such as passing it as constructor parameter).