Mockito Assert resulting NullPointerException

Question

I am writing a simple test case but getting a null pointer exception in the return value. Although when I debug the actual mocking is working, and my main code is also being triggered

My Test Case

  @Test
  public void testEmptyRequests() {
     List<MyPojo> list = new ArrayList();
     String env = "env-stub";
     when(myService.fetchRecords(env)).thenReturn(list);
     Assert.assertEquals(Integer.valueOf(0), myController.process(env, 1));
 }

My Method

      @Async
      public Integer process(String environment, Integer id) {
      List<MyPojo> list = myService.fetchRecords(environment);
      if (list == null || list .isEmpty()) {
          log.info("[0] claims to process");
         return 0;
        }
            // Other logic here, Not relevant to this test case
     }

Answer 1

change your test method to this:

    @Test
    public void testEmptyRequests() {
        List<MyPojo> list = new ArrayList();
        String env = "env-stub";
        when(myService.fetchRecords(Mockito.anyString())).thenReturn(list);
        Assert.assertEquals(Integer.valueOf(0), myController.process(env, 1));
 }

You should mock the method you are using inside your code.