How to mock new Date() in java using Mockito

Question

I have a function that uses the current time to make some calculations. I\'d like to mock it using mockito.

An example of the class I\'d like to test:

Answer 1

One approach, that does not directly answer the question but might solve the underlying problem (having reproducible tests), is allow the Date as an parameter for tests and add a delegate to the default date.

Like so

public class ClassToTest {

    public long getDoubleTime() {
      return getDoubleTime(new Date());
    }

    long getDoubleTime(Date date) {  // package visibility for tests
      return date.getTime() * 2;
    }
}

In production code, you use getDoubleTime() and test against getDoubleTime(Date date).