Question

I use buster.js and I want to test a function returning the age of a person from her year of birth. My test look like this:

"Should get correct age from year": function () {
    assert(getAgeFromYear(1990) === 22);
}

This will only stay green until the end of 2012. How can I fake the date object in buster.js so that it will be valid in the next years?

Answer 1

Make a function getAgeFromYearDate(int, Date) and test that. Then make a function getAgeFromYear(int) which uses the current Date. That method will look like this:

function getAgeFromYear(year) {
    return getAgeFromYearDate(year, new Date());
}

If getAgeFromYearDate works correctly, you can assume that getAgeFromYear works correctly.