Local method is not updating the instance variables of my mocked class

Question

I am new to mockito. Spent more than a day now, trying to figure out how this works. This is my last resort.

I have a class as follows:

class Check{
  //Map<String, Long> map1 = new HashMap<String, Long>();
  //Map<String, Long> map2 = new HashMap<String, Long>();

boolean myLocalMethod(String key, Map<String, Long> map1){
  if(map1.get(key) == null){
    map1.put("name", (long)10);
    return false;
  }
  else if(map1.get(key) == 10)
          return true;
       else
          return false;
}

I have a test class as follows:

class TestCheck(){
 Check mockTest = mock(Check.class);

 @Test // using testng. That's what I like
 public void testMyLocalMethod(){
   Map<String, Long> map1 = new HashMap<String, Long>();
   Assert.assertFalse(mockTest.myLocalMethod("name", map1));
   map1.put("name", (long)10);
   Assert.assertTrue(mockTest.myLocalMethod("name", map1)); // fails

It will be great if someone can give me some guidance here. Thanks in advance!

Answer 1

When you ask Mockito to mock a class, it overrides your existing implementation. Internally, it defines a new class, which at a basic level would look something like this, if you did it explicitly and don't add any additional behaviour using when or similar:

class MockCheck extends Check {
  @Override
  void myLocalMethod(String key) {}
}

ie calling myLocalMethod doesn't actually invoke the parent class' version of myLocalMethod .

If you want to use your implementation of Check , just instantiate it like a regular object:

Check mockTest = new Check();

Answer 2

As others mentioned, a mock object will not use your actual implementation. But, you can use a Spy object to verify behaviors, while using your actual implementation, see Spying on real objects