Refactored common date and time calculations.

* Added the `DateAndTime::Calculations` module that is included in Time
  and Date. It houses common calculations to reduce duplicated code.
* Simplified and cleaned-up the calculation code.
* Removed duplication in tests by adding a behavior module for shared
  tests. I also added some missing tests.

1 files changed, 186 insertions, 0 deletions

diff --git a/activesupport/test/core_ext/date_and_time_behavior.rb b/activesupport/test/core_ext/date_and_time_behavior.rb
new file mode 100644
index 0000000000..014935b0c0
--- /dev/null
+++ b/activesupport/test/core_ext/date_and_time_behavior.rb
@@ -0,0 +1,186 @@
+require 'abstract_unit'
+
+module DateAndTimeBehavior
+  def test_yesterday
+    assert_equal date_time_init(2005,2,21,10,10,10), date_time_init(2005,2,22,10,10,10).yesterday
+    assert_equal date_time_init(2005,2,28,10,10,10), date_time_init(2005,3,2,10,10,10).yesterday.yesterday
+  end
+
+  def test_tomorrow
+    assert_equal date_time_init(2005,2,23,10,10,10), date_time_init(2005,2,22,10,10,10).tomorrow
+    assert_equal date_time_init(2005,3,2,10,10,10),  date_time_init(2005,2,28,10,10,10).tomorrow.tomorrow
+  end
+
+  def test_days_ago
+    assert_equal date_time_init(2005,6,4,10,10,10),  date_time_init(2005,6,5,10,10,10).days_ago(1)
+    assert_equal date_time_init(2005,5,31,10,10,10),   date_time_init(2005,6,5,10,10,10).days_ago(5)
+  end
+
+  def test_days_since
+    assert_equal date_time_init(2005,6,6,10,10,10),  date_time_init(2005,6,5,10,10,10).days_since(1)
+    assert_equal date_time_init(2005,1,1,10,10,10), date_time_init(2004,12,31,10,10,10).days_since(1)
+  end
+
+  def test_weeks_ago
+    assert_equal date_time_init(2005,5,29,10,10,10),  date_time_init(2005,6,5,10,10,10).weeks_ago(1)
+    assert_equal date_time_init(2005,5,1,10,10,10),   date_time_init(2005,6,5,10,10,10).weeks_ago(5)
+    assert_equal date_time_init(2005,4,24,10,10,10),  date_time_init(2005,6,5,10,10,10).weeks_ago(6)
+    assert_equal date_time_init(2005,2,27,10,10,10),  date_time_init(2005,6,5,10,10,10).weeks_ago(14)
+    assert_equal date_time_init(2004,12,25,10,10,10), date_time_init(2005,1,1,10,10,10).weeks_ago(1)
+  end
+
+  def test_weeks_since
+    assert_equal date_time_init(2005,7,14,10,10,10), date_time_init(2005,7,7,10,10,10).weeks_since(1)
+    assert_equal date_time_init(2005,7,14,10,10,10), date_time_init(2005,7,7,10,10,10).weeks_since(1)
+    assert_equal date_time_init(2005,7,4,10,10,10),  date_time_init(2005,6,27,10,10,10).weeks_since(1)
+    assert_equal date_time_init(2005,1,4,10,10,10),  date_time_init(2004,12,28,10,10,10).weeks_since(1)
+  end
+
+  def test_months_ago
+    assert_equal date_time_init(2005,5,5,10,10,10),  date_time_init(2005,6,5,10,10,10).months_ago(1)
+    assert_equal date_time_init(2004,11,5,10,10,10), date_time_init(2005,6,5,10,10,10).months_ago(7)
+    assert_equal date_time_init(2004,12,5,10,10,10), date_time_init(2005,6,5,10,10,10).months_ago(6)
+    assert_equal date_time_init(2004,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).months_ago(12)
+    assert_equal date_time_init(2003,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).months_ago(24)
+  end
+
+  def test_months_since
+    assert_equal date_time_init(2005,7,5,10,10,10),   date_time_init(2005,6,5,10,10,10).months_since(1)
+    assert_equal date_time_init(2006,1,5,10,10,10),   date_time_init(2005,12,5,10,10,10).months_since(1)
+    assert_equal date_time_init(2005,12,5,10,10,10),  date_time_init(2005,6,5,10,10,10).months_since(6)
+    assert_equal date_time_init(2006,6,5,10,10,10),   date_time_init(2005,12,5,10,10,10).months_since(6)
+    assert_equal date_time_init(2006,1,5,10,10,10),   date_time_init(2005,6,5,10,10,10).months_since(7)
+    assert_equal date_time_init(2006,6,5,10,10,10),   date_time_init(2005,6,5,10,10,10).months_since(12)
+    assert_equal date_time_init(2007,6,5,10,10,10),   date_time_init(2005,6,5,10,10,10).months_since(24)
+    assert_equal date_time_init(2005,4,30,10,10,10),  date_time_init(2005,3,31,10,10,10).months_since(1)
+    assert_equal date_time_init(2005,2,28,10,10,10),  date_time_init(2005,1,29,10,10,10).months_since(1)
+    assert_equal date_time_init(2005,2,28,10,10,10),  date_time_init(2005,1,30,10,10,10).months_since(1)
+    assert_equal date_time_init(2005,2,28,10,10,10),  date_time_init(2005,1,31,10,10,10).months_since(1)
+  end
+
+  def test_years_ago
+    assert_equal date_time_init(2004,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).years_ago(1)
+    assert_equal date_time_init(1998,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).years_ago(7)
+    assert_equal date_time_init(2003,2,28,10,10,10), date_time_init(2004,2,29,10,10,10).years_ago(1) # 1 year ago from leap day
+  end
+
+  def test_years_since
+    assert_equal date_time_init(2006,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).years_since(1)
+    assert_equal date_time_init(2012,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).years_since(7)
+    assert_equal date_time_init(2005,2,28,10,10,10), date_time_init(2004,2,29,10,10,10).years_since(1) # 1 year since leap day
+    assert_equal date_time_init(2182,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).years_since(177)
+  end
+
+  def test_beginning_of_month
+    assert_equal date_time_init(2005,2,1,0,0,0), date_time_init(2005,2,22,10,10,10).beginning_of_month
+  end
+
+  def test_beginning_of_quarter
+    assert_equal date_time_init(2005,1,1,0,0,0),  date_time_init(2005,2,15,10,10,10).beginning_of_quarter
+    assert_equal date_time_init(2005,1,1,0,0,0),  date_time_init(2005,1,1,0,0,0).beginning_of_quarter
+    assert_equal date_time_init(2005,10,1,0,0,0), date_time_init(2005,12,31,10,10,10).beginning_of_quarter
+    assert_equal date_time_init(2005,4,1,0,0,0),  date_time_init(2005,6,30,23,59,59).beginning_of_quarter
+  end
+
+  def test_end_of_quarter
+    assert_equal date_time_init(2007,3,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,2,15,10,10,10).end_of_quarter
+    assert_equal date_time_init(2007,3,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,3,31,0,0,0).end_of_quarter
+    assert_equal date_time_init(2007,12,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,12,21,10,10,10).end_of_quarter
+    assert_equal date_time_init(2007,6,30,23,59,59,Rational(999999999, 1000)), date_time_init(2007,4,1,0,0,0).end_of_quarter
+    assert_equal date_time_init(2008,6,30,23,59,59,Rational(999999999, 1000)), date_time_init(2008,5,31,0,0,0).end_of_quarter
+  end
+
+  def test_beginning_of_year
+    assert_equal date_time_init(2005,1,1,0,0,0), date_time_init(2005,2,22,10,10,10).beginning_of_year
+  end
+
+  def test_next_week
+    assert_equal date_time_init(2005,2,28,0,0,0),  date_time_init(2005,2,22,15,15,10).next_week
+    assert_equal date_time_init(2005,3,4,0,0,0),   date_time_init(2005,2,22,15,15,10).next_week(:friday)
+    assert_equal date_time_init(2006,10,30,0,0,0), date_time_init(2006,10,23,0,0,0).next_week
+    assert_equal date_time_init(2006,11,1,0,0,0),  date_time_init(2006,10,23,0,0,0).next_week(:wednesday)
+  end
+
+  def test_next_month_on_31st
+    assert_equal date_time_init(2005,9,30,15,15,10), date_time_init(2005,8,31,15,15,10).next_month
+  end
+
+  def test_next_quarter_on_31st
+    assert_equal date_time_init(2005,11,30,15,15,10), date_time_init(2005,8,31,15,15,10).next_quarter
+  end
+
+  def test_next_year
+    assert_equal date_time_init(2006,6,5,10,10,10), date_time_init(2005,6,5,10,10,10).next_year
+  end
+
+  def test_prev_week
+    assert_equal date_time_init(2005,2,21,0,0,0),  date_time_init(2005,3,1,15,15,10).prev_week
+    assert_equal date_time_init(2005,2,22,0,0,0),  date_time_init(2005,3,1,15,15,10).prev_week(:tuesday)
+    assert_equal date_time_init(2005,2,25,0,0,0),  date_time_init(2005,3,1,15,15,10).prev_week(:friday)
+    assert_equal date_time_init(2006,10,30,0,0,0), date_time_init(2006,11,6,0,0,0).prev_week
+    assert_equal date_time_init(2006,11,15,0,0,0), date_time_init(2006,11,23,0,0,0).prev_week(:wednesday)
+  end
+
+  def test_prev_month_on_31st
+    assert_equal date_time_init(2004,2,29,10,10,10), date_time_init(2004,3,31,10,10,10).prev_month
+  end
+
+  def test_prev_quarter_on_31st
+    assert_equal date_time_init(2004,2,29,10,10,10), date_time_init(2004,5,31,10,10,10).prev_quarter
+  end
+
+  def test_prev_year
+    assert_equal date_time_init(2004,6,5,10,10,10),  date_time_init(2005,6,5,10,10,10).prev_year
+  end
+
+  def test_days_to_week_start
+    assert_equal 0, date_time_init(2011,11,01,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 1, date_time_init(2011,11,02,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 2, date_time_init(2011,11,03,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 3, date_time_init(2011,11,04,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 4, date_time_init(2011,11,05,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 5, date_time_init(2011,11,06,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 6, date_time_init(2011,11,07,0,0,0).days_to_week_start(:tuesday)
+
+    assert_equal 3, date_time_init(2011,11,03,0,0,0).days_to_week_start(:monday)
+    assert_equal 3, date_time_init(2011,11,04,0,0,0).days_to_week_start(:tuesday)
+    assert_equal 3, date_time_init(2011,11,05,0,0,0).days_to_week_start(:wednesday)
+    assert_equal 3, date_time_init(2011,11,06,0,0,0).days_to_week_start(:thursday)
+    assert_equal 3, date_time_init(2011,11,07,0,0,0).days_to_week_start(:friday)
+    assert_equal 3, date_time_init(2011,11,8,0,0,0).days_to_week_start(:saturday)
+    assert_equal 3, date_time_init(2011,11,9,0,0,0).days_to_week_start(:sunday)
+  end
+
+  def test_beginning_of_week
+    assert_equal date_time_init(2005,1,31,0,0,0),  date_time_init(2005,2,4,10,10,10).beginning_of_week
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,11,28,0,0,0).beginning_of_week #monday
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,11,29,0,0,0).beginning_of_week #tuesday
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,11,30,0,0,0).beginning_of_week #wednesday
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,12,01,0,0,0).beginning_of_week #thursday
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,12,02,0,0,0).beginning_of_week #friday
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,12,03,0,0,0).beginning_of_week #saturday
+    assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,12,04,0,0,0).beginning_of_week #sunday
+  end
+
+  def test_end_of_week
+    assert_equal date_time_init(2008,1,6,23,59,59,Rational(999999999, 1000)), date_time_init(2007,12,31,10,10,10).end_of_week
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,8,27,0,0,0).end_of_week #monday
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,8,28,0,0,0).end_of_week #tuesday
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,8,29,0,0,0).end_of_week #wednesday
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,8,30,0,0,0).end_of_week #thursday
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,8,31,0,0,0).end_of_week #friday
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,9,01,0,0,0).end_of_week #saturday
+    assert_equal date_time_init(2007,9,2,23,59,59,Rational(999999999, 1000)), date_time_init(2007,9,02,0,0,0).end_of_week #sunday
+  end
+
+  def test_end_of_month
+    assert_equal date_time_init(2005,3,31,23,59,59,Rational(999999999, 1000)), date_time_init(2005,3,20,10,10,10).end_of_month
+    assert_equal date_time_init(2005,2,28,23,59,59,Rational(999999999, 1000)), date_time_init(2005,2,20,10,10,10).end_of_month
+    assert_equal date_time_init(2005,4,30,23,59,59,Rational(999999999, 1000)), date_time_init(2005,4,20,10,10,10).end_of_month
+  end
+
+  def test_end_of_year
+    assert_equal date_time_init(2007,12,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,2,22,10,10,10).end_of_year
+    assert_equal date_time_init(2007,12,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,12,31,10,10,10).end_of_year
+  end
+end