How to fake Time.now?

I really like the Timecop library. You can do time warps in block form (just like time-warp):

Timecop.travel(6.days.ago) do  @model = TimeSensitiveMode.newendassert @model.times_up!

(Yes, you can nest block-form time travel.)

You can also do declarative time travel:

class MyTest < Test::Unit::TestCase  def setup    Timecop.travel(...)  end  def teardown    Timecop.return  endend

I have some cucumber helpers for Timecop here. They let you do things like:

Given it is currently January 24, 2008And I go to the new post pageAnd I fill in "title" with "An old post"And I fill in "body" with "..."And I press "Submit"And we jump in our Delorean and return to the presentWhen I go to the home pageI should not see "An old post"

Personally I prefer to make the clock injectable, like so:

def hello(clock=Time)  puts "the time is now: #{clock.now}"end

Or:

class MyClass  attr_writer :clock  def initialize    @clock = Time  end  def hello    puts "the time is now: #{@clock.now}"  endend

However, many prefer to use a mocking/stubbing library. In RSpec/flexmock you can use:

Time.stub!(:now).and_return(Time.mktime(1970,1,1))

Or in Mocha:

Time.stubs(:now).returns(Time.mktime(1970,1,1))

I'm using RSpec and I did this: Time.stub!(:now).and_return(2.days.ago) before I call Time.now. In that way I'm able to control the time I used for that particular test case