Mocking time in Java 8's java.time API

Question

Joda Time has a nice DateTimeUtils.setCurrentMillisFixed() to mock time.

It\'s very practical in tests.

Is there an equivalent in Java 8\'s java.time API

Answer 1

I find using Clock clutters your production code.

You can use JMockit or PowerMock to mock static method invocations in your test code. Example with JMockit:

@Test
public void testSth() {
  LocalDate today = LocalDate.of(2000, 6, 1);

  new Expectations(LocalDate.class) {{
      LocalDate.now(); result = today;
  }};

  Assert.assertEquals(LocalDate.now(), today);
}

EDIT: After reading the comments on Jon Skeet's answer to a similar question here on SO I disagree with my past self. More than anything else the argument convinced me that you cannot parallize tests when you mock static methods.

You can/must still use static mocking if you have to deal with legacy code, though.