Invalid Time.now on RSpec - ruby-on-rails

How do I set the correct Time on RSpec.
[2] pry(#<RSpec::ExampleGroups::Device::Creation::Security>)> Time.now
=> Fri, 01 Jan 2016 10:00:00 CET +01:00
On rails console I have the correct time:
[1] pry(main)> Time.now
=> 2015-12-11 12:41:36 -0500
I don't want to stub it, because I'm not passing the time to my class. Have the following method in the class I'm testing:
def within_expiration?
Time.now - user.sms_sent_date < time_limit_in_seconds
end
This is not behaving as expected because Time.now is Jan 1, 2016
user.sms_sent_date has right date.

Make sure you don't have any library that is currently altering your Time in the spec.
For example, one of the most commonly used is Timecop. Make sure you don't setup it globally, instead use the blocks or before/after to properly mock the date and teardown the mock when no longer required.

Related

Converting time zone of Rails ActiveRecord timestamps

I extended the Time class in my Rails projects so I can easily get the time in NYC:
/lib/extensions.rb .
class Time
# Get NYC time:
def nyc
self.in_time_zone('Eastern Time (US & Canada)')
end
end
Testing it out, looks good:
time_a = Time.now.utc.nyc
=> Sun, 21 Apr 2019 18:42:12 EDT -04:00
The problem is when I pull timestamps from the DB:
time_b = object.created_at.in_time_zone('Eastern Time (US & Canada)')
=> Sun, 21 Apr 2019 17:22:04 EDT -04:00
time_c = object.created_at.nyc
=> Sun, 21 Apr 2019 17:22:04 UTC +00:00
Super confused. Converting the timestamp to EDT works when I use in_time_zone in the console, but not when I use the extension? Even though my extension method works on Time objects I create in console? What's happening here?
(Note: Time instances in Rails are in fact instances of ActiveSupport::TimeWithZone. "TimeWithZone instances implement the same API as Ruby Time instances, so that Time and TimeWithZone instances are interchangeable." - ActiveSupportTimeWithZone)
you would need to patch ActiveSupport::TimeWithZone instead of Time, e.g.
class ActiveSupport::TimeWithZone
def nyc
in_time_zone('Eastern Time (US & Canada)')
end
end
Time.zone.now.nyc # => Mon, 22 Apr 2019 06:44:41 EDT -04:00
User.last.created_at.nyc # => Sun, 21 Apr 2019 13:34:45 EDT -04:00
https://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html
(edit: I previously said "DateTime" instead of "ActiveSupport::TimeWithZone")

Time difference in rspec

I'm writing a simple class to parse strings into relative dates.
module RelativeDate
class InvalidString < StandardError; end
class Parser
REGEX = /([0-9]+)_(day|week|month|year)_(ago|from_now)/
def self.to_time(value)
if captures = REGEX.match(value)
captures[1].to_i.send(captures[2]).send(captures[3])
else
raise InvalidString, "#{value} could not be parsed"
end
end
end
end
The code seems to work fine.
Now when I try my specs I get a time difference only in year and month
require 'spec_helper'
describe RelativeDate::Parser do
describe "#to_time" do
before do
Timecop.freeze
end
['day','week','month','year'].each do |type|
it "should parse #{type} correctly" do
RelativeDate::Parser.to_time("2_#{type}_ago").should == 2.send(type).ago
RelativeDate::Parser.to_time("2_#{type}_from_now").should == 2.send(type).from_now
end
end
after do
Timecop.return
end
end
end
Output
..FF
Failures:
1) RelativeDate::Parser#to_time should parse year correctly
Failure/Error: RelativeDate::Parser.to_time("2_#{type}_ago").should == 2.send(type).ago
expected: Wed, 29 Aug 2012 22:40:14 UTC +00:00
got: Wed, 29 Aug 2012 10:40:14 UTC +00:00 (using ==)
Diff:
## -1,2 +1,2 ##
-Wed, 29 Aug 2012 22:40:14 UTC +00:00
+Wed, 29 Aug 2012 10:40:14 UTC +00:00
# ./spec/lib/relative_date/parser_spec.rb:11:in `(root)'
2) RelativeDate::Parser#to_time should parse month correctly
Failure/Error: RelativeDate::Parser.to_time("2_#{type}_ago").should == 2.send(type).ago
expected: Sun, 29 Jun 2014 22:40:14 UTC +00:00
got: Mon, 30 Jun 2014 22:40:14 UTC +00:00 (using ==)
Diff:
## -1,2 +1,2 ##
-Sun, 29 Jun 2014 22:40:14 UTC +00:00
+Mon, 30 Jun 2014 22:40:14 UTC +00:00
# ./spec/lib/relative_date/parser_spec.rb:11:in `(root)'
Finished in 0.146 seconds
4 examples, 2 failures
Failed examples:
rspec ./spec/lib/relative_date/parser_spec.rb:10 # RelativeDate::Parser#to_time should parse year correctly
rspec ./spec/lib/relative_date/parser_spec.rb:10 # RelativeDate::Parser#to_time should parse month correctly
The first one seems like a time zone issue but the other one is even a day apart? I'm really clueless on this one.
This is a fascinating problem!
First, this has nothing to do with Timecop or RSpec. The problem can be reproduced in the Rails console, as follows:
2.0.0-p247 :001 > 2.months.ago
=> Mon, 30 Jun 2014 20:46:19 UTC +00:00
2.0.0-p247 :002 > 2.months.send(:ago)
DEPRECATION WARNING: Calling #ago or #until on a number (e.g. 5.ago) is deprecated and will be removed in the future, use 5.seconds.ago instead. (called from irb_binding at (irb):2)
=> Wed, 02 Jul 2014 20:46:27 UTC +00:00
[Note: This answer uses the example of months, but the same is true for the alias month as well as year and years.]
Rails adds the month method to the Integer class, returning an ActiveSupport::Duration object, which is a "proxy object" containing a method_missing method which redirects any calls to the method_missing method of the "value" it is serving as a proxy for.
When you call ago directly, it's handled by the ago method in the Duration class itself. When you try to invoke ago via send, however, send is not defined in Duration and is not defined in the BasicObject that all proxy objects inherit from, so the method_missing method of Rails' Duration is invoked which in turn calls send on the integer "value" of the proxy, resulting in the invocation of ago in Numeric. In your case, this results in a change of date equal to 2*30 days.
The only methods you have to work with are those defined by Duration itself and those defined by BasicObject. The latter are as follows:
2.0.0-p247 :023 > BasicObject.instance_methods
=> [:==, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__, :__id__]
In addition to the instance_eval you discovered, you can use __send__.
Here's the definition of method_missing from duration.rb
def method_missing(method, *args, &block) #:nodoc:
value.send(method, *args, &block)
end
value in this case refers to the number of seconds in the Duration object. If you redefine method_missing to special case ago, you can get your test to pass. Or you can alias send to __send__ as follows:
class ActiveSupport::Duration
alias send __send__
end
Here's another example of how this method_missing method from Duration works:
macbookair1:so1 palfvin$ rails c
Loading development environment (Rails 4.1.1)
irb: warn: can't alias context from irb_context.
2.0.0-p247 :001 > class ActiveSupport::Duration
2.0.0-p247 :002?> def foo
2.0.0-p247 :003?> 'foobar'
2.0.0-p247 :004?> end
2.0.0-p247 :005?> end
=> nil
2.0.0-p247 :006 > 2.months.foo
=> "foobar"
2.0.0-p247 :007 > 2.months.respond_to?(:foo)
=> false
2.0.0-p247 :008 >
You can call the newly defined foo directly, but because BasicObject doesn't implement respond_to?, you can't "test" that the method is defined there. For the same reason, method(:ago) on a Duration object returns #<Method: Fixnum(Numeric)#ago> because that's the ago method defined on value.

Ruby / Rails - Change the timezone of a Time, without changing the value

I have a record foo in the database which has :start_time and :timezone attributes.
The :start_time is a Time in UTC - 2001-01-01 14:20:00, for example.
The :timezone is a string - America/New_York, for example.
I want to create a new Time object with the value of :start_time but whose timezone is specified by :timezone. I do not want to load the :start_time and then convert to :timezone, because Rails will be clever and update the time from UTC to be consistent with that timezone.
Currently,
t = foo.start_time
=> 2000-01-01 14:20:00 UTC
t.zone
=> "UTC"
t.in_time_zone("America/New_York")
=> Sat, 01 Jan 2000 09:20:00 EST -05:00
Instead, I want to see
=> Sat, 01 Jan 2000 14:20:00 EST -05:00
ie. I want to do:
t
=> 2000-01-01 14:20:00 UTC
t.zone = "America/New_York"
=> "America/New_York"
t
=> 2000-01-01 14:20:00 EST
Sounds like you want something along the lines of
ActiveSupport::TimeZone.new('America/New_York').local_to_utc(t)
This says convert this local time (using the zone) to utc. If you have Time.zone set then you can of course to
Time.zone.local_to_utc(t)
This won't use the timezone attached to t - it assumes that it's local to the time zone you are converting from.
One edge case to guard against here is DST transitions: the local time you specify may not exist or may be ambiguous.
I've just faced the same problem and here is what I'm going to do:
t = t.asctime.in_time_zone("America/New_York")
Here is the documentation on asctime
If you're using Rails, here is another method along the lines of Eric Walsh's answer:
def set_in_timezone(time, zone)
Time.use_zone(zone) { time.to_datetime.change(offset: Time.zone.now.strftime("%z")) }
end
You need to add the time offset to your time after you convert it.
The easiest way to do this is:
t = Foo.start_time.in_time_zone("America/New_York")
t -= t.utc_offset
I am not sure why you would want to do this, though it is probably best to actually work with times the way they are built. I guess some background on why you need to shift time and timezones would be helpful.
Actually, I think you need to subtract the offset after you convert it, as in:
1.9.3p194 :042 > utc_time = Time.now.utc
=> 2013-05-29 16:37:36 UTC
1.9.3p194 :043 > local_time = utc_time.in_time_zone('America/New_York')
=> Wed, 29 May 2013 12:37:36 EDT -04:00
1.9.3p194 :044 > desired_time = local_time-local_time.utc_offset
=> Wed, 29 May 2013 16:37:36 EDT -04:00
Depends on where you are going to use this Time.
When your time is an attribute
If time is used as an attribute, you can use the same date_time_attribute gem:
class Task
include DateTimeAttribute
date_time_attribute :due_at
end
task = Task.new
task.due_at_time_zone = 'Moscow'
task.due_at # => Mon, 03 Feb 2013 22:00:00 MSK +04:00
task.due_at_time_zone = 'London'
task.due_at # => Mon, 03 Feb 2013 22:00:00 GMT +00:00
When you set a separate variable
Use the same date_time_attribute gem:
my_date_time = DateTimeAttribute::Container.new(Time.zone.now)
my_date_time.date_time # => 2001-02-03 22:00:00 KRAT +0700
my_date_time.time_zone = 'Moscow'
my_date_time.date_time # => 2001-02-03 22:00:00 MSK +0400
Here's another version that worked better for me than the current answers:
now = Time.now
# => 2020-04-15 12:07:10 +0200
now.strftime("%F %T.%N").in_time_zone("Europe/London")
# => Wed, 15 Apr 2020 12:07:10 BST +01:00
It carries over nanoseconds using "%N". If you desire another precision, see this strftime reference.
The question's about Rails but it seems, like me, not everyone here is on the ActiveSupport train, so yet another option:
irb(main):001:0> require "time"
=> true
irb(main):003:0> require "tzinfo"
=> true
irb(main):004:0> t = Time.parse("2000-01-01 14:20:00 UTC")
=> 2000-01-01 14:20:00 UTC
irb(main):005:0> tz = TZInfo::Timezone.get("America/New_York")
=> #<TZInfo::DataTimezone: America/New_York>
irb(main):008:0> utc = tz.local_to_utc(t)
=> 2000-01-01 19:20:00 UTC
irb(main):009:0> tz.utc_to_local(utc)
=> 2000-01-01 14:20:00 -0500
irb(main):010:0>
local_to_utc not doing the opposite of utc_to_local might look like a bug but it is at least documented: https://github.com/tzinfo/tzinfo says:
The offset of the time is ignored - it is treated as if it were a local time for the time zone
I managed to do this by calling change with the desired time zone:
>> t = Time.current.in_time_zone('America/New_York')
=> Mon, 08 Aug 2022 12:04:36.934007000 EDT -04:00
>> t.change(zone: 'Etc/UTC')
=> Mon, 08 Aug 2022 12:04:36.934007000 UTC +00:00
https://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html#method-i-change
def relative_time_in_time_zone(time, zone)
DateTime.parse(time.strftime("%d %b %Y %H:%M:%S #{time.in_time_zone(zone).formatted_offset}"))
end
Quick little function I came up with to solve the job. If someone has a more efficient way of doing this please post it!
I spent significant time struggling with TimeZones as well, and after tinkering with Ruby 1.9.3 realized that you don't need to convert to a named timezone symbol before converting:
my_time = Time.now
west_coast_time = my_time.in_time_zone(-8) # Pacific Standard Time
east_coast_time = my_time.in_time_zone(-5) # Eastern Standard Time
What this implies is that you can focus on getting the appropriate time setup first in the region you want, the way you would think about it (at least in my head I partition it this way), and then convert at the end to the zone you want to verify your business logic with.
This also works for Ruby 2.3.1.
I have created few helper methods one of which just does the same thing as is asked by the original author of the post at Ruby / Rails - Change the timezone of a Time, without changing the value.
Also I have documented few peculiarities I observed and also these helpers contains methods to completely ignore automatic day-light savings applicable while time-conversions which is not available out-of-the-box in Rails framework:
def utc_offset_of_given_time(time, ignore_dst: false)
# Correcting the utc_offset below
utc_offset = time.utc_offset
if !!ignore_dst && time.dst?
utc_offset_ignoring_dst = utc_offset - 3600 # 3600 seconds = 1 hour
utc_offset = utc_offset_ignoring_dst
end
utc_offset
end
def utc_offset_of_given_time_ignoring_dst(time)
utc_offset_of_given_time(time, ignore_dst: true)
end
def change_offset_in_given_time_to_given_utc_offset(time, utc_offset)
formatted_utc_offset = ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, false)
# change method accepts :offset option only on DateTime instances.
# and also offset option works only when given formatted utc_offset
# like -0500. If giving it number of seconds like -18000 it is not
# taken into account. This is not mentioned clearly in the documentation
# , though.
# Hence the conversion to DateTime instance first using to_datetime.
datetime_with_changed_offset = time.to_datetime.change(offset: formatted_utc_offset)
Time.parse(datetime_with_changed_offset.to_s)
end
def ignore_dst_in_given_time(time)
return time unless time.dst?
utc_offset = time.utc_offset
if utc_offset < 0
dst_ignored_time = time - 1.hour
elsif utc_offset > 0
dst_ignored_time = time + 1.hour
end
utc_offset_ignoring_dst = utc_offset_of_given_time_ignoring_dst(time)
dst_ignored_time_with_corrected_offset =
change_offset_in_given_time_to_given_utc_offset(dst_ignored_time, utc_offset_ignoring_dst)
# A special case for time in timezones observing DST and which are
# ahead of UTC. For e.g. Tehran city whose timezone is Iran Standard Time
# and which observes DST and which is UTC +03:30. But when DST is active
# it becomes UTC +04:30. Thus when a IRDT (Iran Daylight Saving Time)
# is given to this method say '05-04-2016 4:00pm' then this will convert
# it to '05-04-2016 5:00pm' and update its offset to +0330 which is incorrect.
# The updated UTC offset is correct but the hour should retain as 4.
if utc_offset > 0
dst_ignored_time_with_corrected_offset -= 1.hour
end
dst_ignored_time_with_corrected_offset
end
Examples which can be tried on rails console or a ruby script after wrapping the above methods in a class or module:
dd1 = '05-04-2016 4:00pm'
dd2 = '07-11-2016 4:00pm'
utc_zone = ActiveSupport::TimeZone['UTC']
est_zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
tehran_zone = ActiveSupport::TimeZone['Tehran']
utc_dd1 = utc_zone.parse(dd1)
est_dd1 = est_zone.parse(dd1)
tehran_dd1 = tehran_zone.parse(dd1)
utc_dd1.dst?
est_dd1.dst?
tehran_dd1.dst?
ignore_dst = true
utc_to_est_time = utc_dd1.in_time_zone(est_zone.name)
if utc_to_est_time.dst? && !!ignore_dst
utc_to_est_time = ignore_dst_in_given_time(utc_to_est_time)
end
puts utc_to_est_time
Hope this helps.
This worked well for me
date = '23/11/2020'
time = '08:00'
h, m = time.split(':')
timezone = 'Europe/London'
date.to_datetime.in_time_zone(timezone).change(hour: h, min: m)
This changes the timezone to 'EST' without changing the time:
time = DateTime.current
Time.find_zone("EST").local(
time.year,
time.month,
time.day,
time.hour,
time.min,
time.sec,
)

Ruby String to_time broken?

I would expect Time and to_time to be reflective.
UPDATE
This is the answer, if you add the parameter :local, it doesn't ignore the offset. I find it wierd that it ignores data (the offset) by default, though...
Time.zone.now.to_s.to_time(:local) returns 2012-03-20 14:39:03 +0100
/UPDATE
> Time.zone.now.to_s
=> "2012-03-20 12:50:05 +0100"
> Time.zone.now.to_s.to_time.to_s
=> "2012-03-20 12:50:05 UTC"
# PROBLEM:
# UTC is +0000, meaning that there is 1 hour diff in the above
> Time.zone.now
=> Tue, 20 Mar 2012 12:51:32 CET +01:00
> Time.zone.now.to_time
=> Tue, 20 Mar 2012 12:51:32 CET +01:00
> Time.zone.now.to_json
=> "\"2012-03-20T12:50:36+01:00\""
> Time.zone.now.to_json.to_time
=> 2012-03-20 12:50:36 UTC
I have this problem with JSON messages. Anyway, I wouldn't expect to_time to actually change the time. OK to translate to UTC, probably, but it should adjust time accordingly. Anybody know if this is a known issue or "by design"?
This method, String#to_time, defined in ActiveSupport takes one parameter, form, which can be either :utc (default) or :local. So by default, it always returns a Time in UTC.
To get a Time with timezone:
Time.zone.parse("2012-03-20T12:50:36+01:00")

Override what Ruby thinks is the current time in Time.now?

I want to create test data for an application, and there are a lot of time_at attributes being tracked, too many to override in a maintainable way. What I'm thinking is, can I just change the base reference time variable in Ruby?
This would make it so created_at, updated_at, last_login_at, etc., could be set to an artificial time, so I could do this in tests:
Date.today #=> Thu, 30 Dec 2010
Time.system_time_offset = 1.week.ago # made up
Date.today #=> Thu, 23 Dec 2010
Time.now #=> Thu Dec 23 14:08:38 -0600 2010
user_1 = User.create!
user_1.created_at #=> Thu Dec 23 14:08:38 -0600 2010
Time.reset_system_time # made up
user_2 = User.create!
user_1.created_at #=> Thu Dec 30 14:08:38 -0600 2010
Is there a way to do this?
You could use Mocha to change the return value of Time.now during a test:
Time.stubs(:now).returns(Time.now - 1.day)
A good gem for this is Timecop: https://github.com/travisjeffery/timecop.
You can freeze time or change the time (while it continues to progress) very easily.
Ex.
Time.now
# => 2014-03-14 13:17:02 -0400
Timecop.travel 2.hours.ago
Time.now
# => 2014-03-14 11:17:04 -0400
Its nicer than the mocha solution since all time functions will be affected equally, so you won't have a test where Time.now is returning something different then DateTime.now
Its also more up-to-date than the time-warp gem suggested in another answer.
I use the timewarp gem for this sort of thing. You just put your code in a pretend_now_is(time) block and the code inside will be executed as if that was the actual time.
http://github.com/harvesthq/time-warp
Here's an example
def test_should_find_company_needing_reminded_today
pretend_now_is(Time.utc(2008,"jul",24,20)) do #=> Thu Jul 24 20:00:00 UTC 2008
#company.reminder_day = 'Thursday'
#company.save
companies = Company.find_companies_needing_reminded_today
assert_equal true, companies.include?(#company)
end
end
Honestly, I usually write tests for current time to check if the timestamp is within a reasonable range. i.e., check if the timestamp is greater than 1.minute.ago. Changing the system clock is likely to have all kinds of unpredictable side-effects, so you don't want to do that. You might be able to track down all the places in Ruby where the current time is accessed (though I think most methods just use Time.now) and monkey-patch them for the tests, but I'd probably still prefer just checking the timestamp is within a sane range.
It's also possible to (yuck) monkeypatch Time:
$start = Time.now - 86400 # this time yesterday
class Time
class << Time
def new
$start
end
def now
Time.new
end
end
end
puts(Time.now)
puts($start)

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