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, &block)
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
block.call
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
