# Distance\_of\_time\_in\_words fails in test **URL:** \ **Category:** Rails\ **Created:** [July 5, 2009, 7:02am UTC](https://www.ruby-forum.com/t/distance-of-time-in-words-fails-in-test/171557 "2009-07-05T07:02:30Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [July 5, 2009, 7:02am UTC](https://www.ruby-forum.com/t/distance-of-time-in-words-fails-in-test/171557/1 "2009-07-05T07:02:30Z")
I have a DateTime object (from DateTime.now), and an ActiveSupport::TimeWithZone object (comes from a date in the DB). I’m passing these values to the helper method distance\_of\_time\_in\_words: \<%= distance\_of\_time\_in\_words(DateTime.now, @myinstance.mydate) %\> In the implementation of this helper is the following: distance\_in\_minutes = (((to\_time - from\_time).abs)/60).round In production, this works as expected. In testing, this results in: ActionView::TemplateError: undefined method `abs’ for Sun Oct 26 19:49:44 UTC 1980:Time Here’s where it gets strange. I opened this up in the debugger in both environments. In test, a DateTime minus a TimeWithZone gives me a Time. Time doesn’t have an abs method, so this fails with a NoMethod exception. In production a DateTime minus a TimeWithZone results in a Rational, which does have abs! Why the different behavior in these two environments? I don’t see the DateTime minus operator being redefined by rails anywhere, but maybe I’m not looking in the right place. I’m using Rails version 2.2.2. ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [July 5, 2009, 7:57am UTC](https://www.ruby-forum.com/t/distance-of-time-in-words-fails-in-test/171557/2 "2009-07-05T07:57:25Z")
Actually, I was looking at the parameters in the wrong order. I need the - operator from the to\_date wich is the TimeWithZone. That’s defined here: ``` def -(other) # If we're subtracting a Duration of variable length (i.e., ``` years, months, days), move backwards from #time, # otherwise move backwards #utc, for accuracy when moving across DST boundaries if other.acts\_like?(:time) utc - other elsif duration\_of\_variable\_length?(other) method\_missing(:-, other) else result = utc.acts\_like?(:date) ? utc.ago(other) : utc - other rescue utc.ago(other) result.in\_time\_zone(time\_zone) end end The rails console tells me I should hit the first condition, resulting in a Time (which doesn’t support abs). I still haven’t found the magic that makes this work in production. Loading development environment (Rails 2.2.2) > > a = DateTime.now > > =\> Sun, 05 Jul 2009 01:55:13 -0400 > > > a.class > > =\> DateTime > > > b = Time.zone.now > > =\> Sun, 05 Jul 2009 05:55:31 UTC +00:00 > > > b.class > > =\> ActiveSupport::TimeWithZone > > > c=b-a > > =\> Thu Jan 01 00:00:18 UTC 1970 > > > c.class > > =\> Time > > > ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [July 5, 2009, 8:19pm UTC](https://www.ruby-forum.com/t/distance-of-time-in-words-fails-in-test/171557/3 "2009-07-05T20:19:59Z")
A little more information… Not all ActiveSupport::TimeWithZone instances are alike. In the definition of the minus operator (above) I consistantly see that other.acts\_like?(:time) so it always returns “utc-other”. The difference is, the type of utc! When the TimeWithZone is created from the DB, utc is a Date (and a Date - Date = rational). When the TimeWithZone is created from a test fixture, utc is a Time (and a Time - Date = Time). Now, at least, I understand how its possible that my subtraction is returning a different type in each case. Unfortunately for me this means the real answer is buried somewhere inside ActiceRecord code and I’m still not smart enough to proceed. 🙂 Two questions: 1. Why isn’t anyone else hitting this? The combination of using test fixtures + calling distance\_of\_time\_in\_words can’t be THAT rare, can it? 2. Any suggestions for a workaround? ---
**Author:** ![brian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/97f17d/32.png) [@brian](https://www.ruby-forum.com/u/brian)\ **Post date:** [July 5, 2009, 9:44pm UTC](https://www.ruby-forum.com/t/distance-of-time-in-words-fails-in-test/171557/4 "2009-07-05T21:44:06Z")
Resolved! Sometimes I’m too stubborn for my own good. Updating rails to 2.3.2 made this problem go away. The helper now works as I expect it to for both DB dates and test fixture dates.