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Diffstat (limited to 'activesupport/lib/active_support/testing/time_helpers.rb')
| -rw-r--r-- | activesupport/lib/active_support/testing/time_helpers.rb | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/testing/time_helpers.rb b/activesupport/lib/active_support/testing/time_helpers.rb new file mode 100644 index 0000000000..8c63815660 --- /dev/null +++ b/activesupport/lib/active_support/testing/time_helpers.rb @@ -0,0 +1,131 @@ +module ActiveSupport + module Testing + class SimpleStubs # :nodoc: + Stub = Struct.new(:object, :method_name, :original_method) + + def initialize + @stubs = {} + end + + def stub_object(object, method_name, return_value) + key = [object.object_id, method_name] + + if stub = @stubs[key] + unstub_object(stub) + end + + new_name = "__simple_stub__#{method_name}" + + @stubs[key] = Stub.new(object, method_name, new_name) + + object.singleton_class.send :alias_method, new_name, method_name + object.define_singleton_method(method_name) { return_value } + end + + def unstub_all! + @stubs.each_value do |stub| + unstub_object(stub) + end + @stubs = {} + end + + private + + def unstub_object(stub) + singleton_class = stub.object.singleton_class + singleton_class.send :undef_method, stub.method_name + singleton_class.send :alias_method, stub.method_name, stub.original_method + singleton_class.send :undef_method, stub.original_method + end + end + + # Containing helpers that helps you test passage of time. + module TimeHelpers + # Changes current time to the time in the future or in the past by a given time difference by + # stubbing +Time.now+ and +Date.today+. + # + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + # travel 1.day + # Time.current # => Sun, 10 Nov 2013 15:34:49 EST -05:00 + # Date.current # => Sun, 10 Nov 2013 + # + # This method also accepts a block, which will return the current time back to its original + # state at the end of the block: + # + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + # travel 1.day do + # User.create.created_at # => Sun, 10 Nov 2013 15:34:49 EST -05:00 + # end + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + def travel(duration, &block) + travel_to Time.now + duration, &block + end + + # Changes current time to the given time by stubbing +Time.now+ and + # +Date.today+ to return the time or date passed into this method. + # + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + # travel_to Time.new(2004, 11, 24, 01, 04, 44) + # Time.current # => Wed, 24 Nov 2004 01:04:44 EST -05:00 + # Date.current # => Wed, 24 Nov 2004 + # + # Dates are taken as their timestamp at the beginning of the day in the + # application time zone. <tt>Time.current</tt> returns said timestamp, + # and <tt>Time.now</tt> its equivalent in the system time zone. Similarly, + # <tt>Date.current</tt> returns a date equal to the argument, and + # <tt>Date.today</tt> the date according to <tt>Time.now</tt>, which may + # be different. (Note that you rarely want to deal with <tt>Time.now</tt>, + # or <tt>Date.today</tt>, in order to honor the application time zone + # please always use <tt>Time.current</tt> and <tt>Date.current</tt>.) + # + # Note that the usec for the time passed will be set to 0 to prevent rounding + # errors with external services, like MySQL (which will round instead of floor, + # leading to off-by-one-second errors). + # + # This method also accepts a block, which will return the current time back to its original + # state at the end of the block: + # + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + # travel_to Time.new(2004, 11, 24, 01, 04, 44) do + # Time.current # => Wed, 24 Nov 2004 01:04:44 EST -05:00 + # end + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + def travel_to(date_or_time) + if date_or_time.is_a?(Date) && !date_or_time.is_a?(DateTime) + now = date_or_time.midnight.to_time + else + now = date_or_time.to_time.change(usec: 0) + end + + simple_stubs.stub_object(Time, :now, now) + simple_stubs.stub_object(Date, :today, now.to_date) + + if block_given? + begin + yield + ensure + travel_back + end + end + end + + # Returns the current time back to its original state, by removing the stubs added by + # `travel` and `travel_to`. + # + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + # travel_to Time.new(2004, 11, 24, 01, 04, 44) + # Time.current # => Wed, 24 Nov 2004 01:04:44 EST -05:00 + # travel_back + # Time.current # => Sat, 09 Nov 2013 15:34:49 EST -05:00 + def travel_back + simple_stubs.unstub_all! + end + + private + + def simple_stubs + @simple_stubs ||= SimpleStubs.new + end + end + end +end |