now()
public
Freezing Time.now with Time.is
Sometimes when writing unit tests/specifications our code sets an attribute of an object using Time.now because running specs/test takes time.
The solution is to “freeze” Time.now with the following Time.is method:
class Time def self.metaclass class << self; self; end end # useful for unit testing # Time.is(Time.now) do # Time.now # => Tue Nov 13 19:31:46 -0500 2007 # sleep 2 # Time.now # => Tue Nov 13 19:31:46 -0500 2007 # end # # Time.is("10/05/2006") do # Time.now # => Thu Oct 05 00:00:00 -0400 2006 # sleep 2 # Time.now # => Thu Oct 05 00:00:00 -0400 2006 # end def self.is(point_in_time) new_time = case point_in_time when String then Time.parse(point_in_time) when Time then point_in_time else raise ArgumentError.new("argument should be a string or time instance") end class << self alias old_now now end metaclass.class_eval do define_method :now do new_time end end yield class << self alias now old_now undef old_now end end end
It’s a good idea to add this to your spec_helper/test_helper and “freeze” time whenever you’re testing functionality that depends on a specific time value.
Time.now in UTC
A quick way to get the current time in UTC is:
Time.new.utc # => Wed Mar 24 14:38:19 UTC 2010
Freezing Time.now
You’d be much better off using the Timecop gem ( rubygems.org/gems/timecop ) than than manually writing monkey-patches to freeze Time.now etc.
It also supports time travel (i.e. changing the time, but allowing the clock to continue running).