How can I mock java.time.LocalDate.now()

Question

In my test case, I need test time sensitive method, in that method we're using java 8 class LocalDate, it is not Joda.

What can I do to change time, when I'm running test

Answer 1

In your code, replace LocalDate.now() with LocalDate.now(clock);.

You can then pass Clock.systemDefaultZone() for production and a fixed clock for testing.

---

This is an example :

First, inject the Clock. If you are using spring boot just do a :

@Bean public Clock clock() {     return Clock.systemDefaultZone(); } 

Second, call LocalDate.now(clock) in your code :

@Component public class SomeClass{      @Autowired     private Clock clock;      public LocalDate someMethod(){          return LocalDate.now(clock);     } } 

Now, inside your unit test class :

// Some fixed date to make your tests private final static LocalDate LOCAL_DATE = LocalDate.of(1989, 01, 13);  // mock your tested class @InjectMocks private SomeClass someClass;  //Mock your clock bean @Mock private Clock clock;  //field that will contain the fixed clock private Clock fixedClock;   @Before public void initMocks() {     MockitoAnnotations.initMocks(this);      //tell your tests to return the specified LOCAL_DATE when calling LocalDate.now(clock)     fixedClock = Clock.fixed(LOCAL_DATE.atStartOfDay(ZoneId.systemDefault()).toInstant(), ZoneId.systemDefault());     doReturn(fixedClock.instant()).when(clock).instant();     doReturn(fixedClock.getZone()).when(clock).getZone(); }  @Test public void testSomeMethod(){     // call the method to test     LocalDate returnedLocalDate = someClass.someMethod();      //assert     assertEquals(LOCAL_DATE, returnedLocalDate); }