Move common DateTime calculations to Date. Closes #8536.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6921 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 223 insertions, 119 deletions

diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index b0fadc4092..15433ca79b 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Move common DateTime calculations to Date.  #8536 [Geoff Buesing]
+
 * Added Date#change (like Time#change) [DHH]
 
 * DateTime#to_time converts to Time unless out of range.  #8512 [Geoff Buesing]
diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index c522256aea..de354540e9 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -52,6 +52,114 @@ module ActiveSupport #:nodoc:
               options[:day]   || options[:mday] || self.day # mday is deprecated
             )
           end
+          
+          # Returns a new Date/DateTime representing the time a number of specified months ago
+          def months_ago(months)
+            months_since(-months)
+          end
+
+          def months_since(months)
+            year, month, day = self.year, self.month, self.day
+
+            month += months
+
+            # in case months is negative
+            while month < 1
+             month += 12
+             year -= 1
+            end
+
+            # in case months is positive
+            while month > 12
+             month -= 12
+             year += 1
+            end
+
+            max = ::Time.days_in_month(month, year)
+            day = max if day > max
+
+            change(:year => year, :month => month, :day => day)
+          end
+
+          # Returns a new Date/DateTime representing the time a number of specified years ago
+          def years_ago(years)
+            change(:year => self.year - years)
+          end
+
+          def years_since(years)
+            change(:year => self.year + years)
+          end
+
+          # Short-hand for years_ago(1)
+          def last_year
+            years_ago(1)
+          end
+
+          # Short-hand for years_since(1)
+          def next_year
+            years_since(1)
+          end
+
+          # Short-hand for months_ago(1)
+          def last_month
+            months_ago(1)
+          end
+
+          # Short-hand for months_since(1)
+          def next_month
+            months_since(1)
+          end
+
+          # Returns a new Date/DateTime representing the "start" of this week (i.e, Monday; DateTime objects will have time set to 0:00)
+          def beginning_of_week
+            days_to_monday = self.wday!=0 ? self.wday-1 : 6
+            result = self - days_to_monday
+            self.acts_like?(:time) ? result.midnight : result
+          end
+          alias :monday :beginning_of_week
+          alias :at_beginning_of_week :beginning_of_week
+
+          # Returns a new Date/DateTime representing the start of the given day in next week (default is Monday).
+          def next_week(day = :monday)
+            days_into_week = { :monday => 0, :tuesday => 1, :wednesday => 2, :thursday => 3, :friday => 4, :saturday => 5, :sunday => 6}
+            result = (self + 7).beginning_of_week + days_into_week[day]
+            self.acts_like?(:time) ? result.change(:hour => 0) : result
+          end          
+
+          # Returns a new ; DateTime objects will have time set to 0:00DateTime representing the start of the month (1st of the month; DateTime objects will have time set to 0:00)
+          def beginning_of_month
+            self.acts_like?(:time) ? change(:day => 1,:hour => 0, :min => 0, :sec => 0) : change(:day => 1)
+          end
+          alias :at_beginning_of_month :beginning_of_month
+
+          # Returns a new Date/DateTime representing the end of the month (last day of the month; DateTime objects will have time set to 0:00)
+          def end_of_month
+            last_day = ::Time.days_in_month( self.month, self.year )
+            self.acts_like?(:time) ? change(:day => last_day,:hour => 0, :min => 0, :sec => 0) : change(:day => last_day)
+          end
+          alias :at_end_of_month :end_of_month
+
+          # Returns a new Date/DateTime representing the start of the quarter (1st of january, april, july, october; DateTime objects will have time set to 0:00)
+          def beginning_of_quarter
+            beginning_of_month.change(:month => [10, 7, 4, 1].detect { |m| m <= self.month })
+          end
+          alias :at_beginning_of_quarter :beginning_of_quarter
+
+          # Returns a new Date/DateTime representing the start of the year (1st of january; DateTime objects will have time set to 0:00)
+          def beginning_of_year
+            self.acts_like?(:time) ? change(:month => 1, :day => 1, :hour => 0, :min => 0, :sec => 0) : change(:month => 1, :day => 1)
+          end
+          alias :at_beginning_of_year :beginning_of_year
+
+          # Convenience method which returns a new Date/DateTime representing the time 1 day ago
+          def yesterday
+            self - 1
+          end
+
+          # Convenience method which returns a new Date/DateTime representing the time 1 day since the instance time
+          def tomorrow
+            self + 1
+          end
         end
       end
     end
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
index 3e62891fcf..8e4197d34b 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -18,7 +18,7 @@ module ActiveSupport #:nodoc:
           ::DateTime.civil(
             options[:year]  || self.year,
             options[:month] || self.month,
-            options[:mday]  || self.mday,
+            options[:day]   || options[:mday] || self.day, # mday is deprecated
             options[:hour]  || self.hour,
             options[:min]   || (options[:hour] ? 0 : self.min),
             options[:sec]   || ((options[:hour] || options[:min]) ? 0 : self.sec),
@@ -33,7 +33,7 @@ module ActiveSupport #:nodoc:
           d = ::Date.new(year + (options.delete(:years) || 0), month, day)
           d = d >> options.delete(:months) if options[:months]
           d = d +  options.delete(:days)   if options[:days]
-          change(options.merge(:year => d.year, :month => d.month, :mday => d.day))
+          change(options.merge(:year => d.year, :month => d.month, :day => d.day))
         end
 
         # Returns a new DateTime representing the time a number of seconds ago
@@ -49,124 +49,18 @@ module ActiveSupport #:nodoc:
         end
         alias :in :since
 
-        # Returns a new DateTime representing the time a number of specified months ago
-         def months_ago(months)
-           months_since(-months)
-         end
-
-         def months_since(months)
-           year, month, mday = self.year, self.month, self.mday
-
-           month += months
-
-           # in case months is negative
-           while month < 1
-             month += 12
-             year -= 1
-           end
-
-           # in case months is positive
-           while month > 12
-             month -= 12
-             year += 1
-           end
-
-           max = ::Time.days_in_month(month, year)
-           mday = max if mday > max
-
-           change(:year => year, :month => month, :mday => mday)
-         end
-
-         # Returns a new DateTime representing the time a number of specified years ago
-         def years_ago(years)
-           change(:year => self.year - years)
-         end
-
-         def years_since(years)
-           change(:year => self.year + years)
-         end
-
-         # Short-hand for years_ago(1)
-         def last_year
-           years_ago(1)
-         end
-
-         # Short-hand for years_since(1)
-         def next_year
-           years_since(1)
-         end
-
-         # Short-hand for months_ago(1)
-         def last_month
-           months_ago(1)
-         end
-
-         # Short-hand for months_since(1)
-         def next_month
-           months_since(1)
-         end
-
-         # Returns a new DateTime representing the "start" of this week (Monday, 0:00)
-         def beginning_of_week
-           days_to_monday = self.wday!=0 ? self.wday-1 : 6
-           (self - days_to_monday).midnight
-         end
-         alias :monday :beginning_of_week
-         alias :at_beginning_of_week :beginning_of_week
-
-         # Returns a new DateTime representing the start of the given day in next week (default is Monday).
-         def next_week(day = :monday)
-           days_into_week = { :monday => 0, :tuesday => 1, :wednesday => 2, :thursday => 3, :friday => 4, :saturday => 5, :sunday => 6}
-           ((self + 7).beginning_of_week + days_into_week[day]).change(:hour => 0)
-         end
-
-         # Returns a new DateTime representing the start of the day (0:00)
-         def beginning_of_day
-           change(:hour => 0)
-         end
-         alias :midnight :beginning_of_day
-         alias :at_midnight :beginning_of_day
-         alias :at_beginning_of_day :beginning_of_day
-
-         # Returns a new DateTime representing the end of the day (23:59:59)
-         def end_of_day
-           change(:hour => 23, :min => 59, :sec => 59)
-         end
-
-         # Returns a new DateTime representing the start of the month (1st of the month, 0:00)
-         def beginning_of_month
-           change(:mday => 1,:hour => 0, :min => 0, :sec => 0)
-         end
-         alias :at_beginning_of_month :beginning_of_month
-
-         # Returns a new DateTime representing the end of the month (last day of the month, 0:00)
-         def end_of_month
-           last_day = ::Time.days_in_month( self.month, self.year )
-           change(:mday => last_day,:hour => 0, :min => 0, :sec => 0)
-         end
-         alias :at_end_of_month :end_of_month
-
-         # Returns  a new DateTime representing the start of the quarter (1st of january, april, july, october, 0:00)
-         def beginning_of_quarter
-           beginning_of_month.change(:month => [10, 7, 4, 1].detect { |m| m <= self.month })
-         end
-         alias :at_beginning_of_quarter :beginning_of_quarter
-
-         # Returns  a new DateTime representing the start of the year (1st of january, 0:00)
-         def beginning_of_year
-           change(:month => 1,:mday => 1,:hour => 0, :min => 0, :sec => 0)
-         end
-         alias :at_beginning_of_year :beginning_of_year
-
-         # Convenience method which returns a new DateTime representing the time 1 day ago
-         def yesterday
-           self - 1
-         end
+        # Returns a new DateTime representing the start of the day (0:00)
+        def beginning_of_day
+          change(:hour => 0)
+        end
+        alias :midnight :beginning_of_day
+        alias :at_midnight :beginning_of_day
+        alias :at_beginning_of_day :beginning_of_day
 
-         # Convenience method which returns a new DateTime representing the time 1 day since the instance time
-         def tomorrow
-           self + 1
-         end
+        # Returns a new DateTime representing the end of the day (23:59:59)
+        def end_of_day
+          change(:hour => 23, :min => 59, :sec => 59)
+        end
       end
     end
   end
diff --git a/activesupport/test/core_ext/date_ext_test.rb b/activesupport/test/core_ext/date_ext_test.rb
index f9891c9358..0d68d6b398 100644
--- a/activesupport/test/core_ext/date_ext_test.rb
+++ b/activesupport/test/core_ext/date_ext_test.rb
@@ -25,5 +25,105 @@ class DateExtCalculationsTest < Test::Unit::TestCase
   def test_change
     assert_equal Date.new(2005, 2, 21), Date.new(2005, 2, 11).change(:day => 21)
     assert_equal Date.new(2007, 5, 11), Date.new(2005, 2, 11).change(:year => 2007, :month => 5)
+    assert_equal Date.new(2006,2,22), Date.new(2005,2,22).change(:year => 2006)
+    assert_equal Date.new(2005,6,22), Date.new(2005,2,22).change(:month => 6)
   end
+  
+  def test_begining_of_week
+    assert_equal Date.new(2005,1,31),  Date.new(2005,2,4).beginning_of_week
+    assert_equal Date.new(2005,11,28), Date.new(2005,11,28).beginning_of_week #monday
+    assert_equal Date.new(2005,11,28), Date.new(2005,11,29).beginning_of_week #tuesday
+    assert_equal Date.new(2005,11,28), Date.new(2005,11,30).beginning_of_week #wednesday
+    assert_equal Date.new(2005,11,28), Date.new(2005,12,01).beginning_of_week #thursday
+    assert_equal Date.new(2005,11,28), Date.new(2005,12,02).beginning_of_week #friday
+    assert_equal Date.new(2005,11,28), Date.new(2005,12,03).beginning_of_week #saturday
+    assert_equal Date.new(2005,11,28), Date.new(2005,12,04).beginning_of_week #sunday
+  end
+
+  def test_beginning_of_month
+    assert_equal Date.new(2005,2,1), Date.new(2005,2,22).beginning_of_month
+  end
+
+  def test_beginning_of_quarter
+    assert_equal Date.new(2005,1,1),  Date.new(2005,2,15).beginning_of_quarter
+    assert_equal Date.new(2005,1,1),  Date.new(2005,1,1).beginning_of_quarter
+    assert_equal Date.new(2005,10,1), Date.new(2005,12,31).beginning_of_quarter
+    assert_equal Date.new(2005,4,1),  Date.new(2005,6,30).beginning_of_quarter
+  end
+
+  def test_end_of_month
+    assert_equal Date.new(2005,3,31), Date.new(2005,3,20).end_of_month
+    assert_equal Date.new(2005,2,28), Date.new(2005,2,20).end_of_month
+    assert_equal Date.new(2005,4,30), Date.new(2005,4,20).end_of_month
+
+  end
+
+  def test_beginning_of_year
+    assert_equal Date.new(2005,1,1).to_s, Date.new(2005,2,22).beginning_of_year.to_s
+  end
+
+  def test_months_ago
+    assert_equal Date.new(2005,5,5),  Date.new(2005,6,5).months_ago(1)
+    assert_equal Date.new(2004,11,5), Date.new(2005,6,5).months_ago(7)
+    assert_equal Date.new(2004,12,5), Date.new(2005,6,5).months_ago(6)
+    assert_equal Date.new(2004,6,5),  Date.new(2005,6,5).months_ago(12)
+    assert_equal Date.new(2003,6,5),  Date.new(2005,6,5).months_ago(24)
+  end
+
+  def test_months_since
+    assert_equal Date.new(2005,7,5),  Date.new(2005,6,5).months_since(1)
+    assert_equal Date.new(2006,1,5),  Date.new(2005,12,5).months_since(1)
+    assert_equal Date.new(2005,12,5), Date.new(2005,6,5).months_since(6)
+    assert_equal Date.new(2006,6,5),  Date.new(2005,12,5).months_since(6)
+    assert_equal Date.new(2006,1,5),  Date.new(2005,6,5).months_since(7)
+    assert_equal Date.new(2006,6,5),  Date.new(2005,6,5).months_since(12)
+    assert_equal Date.new(2007,6,5),  Date.new(2005,6,5).months_since(24)
+  end
+
+  def test_years_ago
+    assert_equal Date.new(2004,6,5),  Date.new(2005,6,5).years_ago(1)
+    assert_equal Date.new(1998,6,5), Date.new(2005,6,5).years_ago(7)
+  end
+
+  def test_years_since
+    assert_equal Date.new(2006,6,5),  Date.new(2005,6,5).years_since(1)
+    assert_equal Date.new(2012,6,5),  Date.new(2005,6,5).years_since(7)
+    assert_equal Date.new(2182,6,5),  Date.new(2005,6,5).years_since(177)
+  end
+
+  def test_last_year
+    assert_equal Date.new(2004,6,5),  Date.new(2005,6,5).last_year
+  end
+
+  def test_yesterday
+    assert_equal Date.new(2005,2,21), Date.new(2005,2,22).yesterday
+    assert_equal Date.new(2005,2,28), Date.new(2005,3,2).yesterday.yesterday
+  end
+
+  def test_tomorrow
+    assert_equal Date.new(2005,2,23), Date.new(2005,2,22).tomorrow
+    assert_equal Date.new(2005,3,2),  Date.new(2005,2,28).tomorrow.tomorrow
+  end
+
+  def test_plus
+    assert_equal Date.new(2006,2,28), Date.new(2005,2,28).advance(:years => 1)
+    assert_equal Date.new(2005,6,28), Date.new(2005,2,28).advance(:months => 4)
+    assert_equal Date.new(2012,9,28), Date.new(2005,2,28).advance(:years => 7, :months => 7)
+    assert_equal Date.new(2013,10,3), Date.new(2005,2,28).advance(:years => 7, :months => 19, :days => 5)
+  end
+
+  def test_next_week
+    assert_equal Date.new(2005,2,28), Date.new(2005,2,22).next_week
+    assert_equal Date.new(2005,3,4), Date.new(2005,2,22).next_week(:friday)
+    assert_equal Date.new(2006,10,30), Date.new(2006,10,23).next_week
+    assert_equal Date.new(2006,11,1), Date.new(2006,10,23).next_week(:wednesday)
+  end
+
+  def test_next_month_on_31st
+    assert_equal Date.new(2005, 9, 30), Date.new(2005, 8, 31).next_month
+  end
+
+  def test_last_month_on_31st
+    assert_equal Date.new(2004, 2, 29), Date.new(2004, 3, 31).last_month
+  end  
 end