Time #yesterday and #tomorrow behave correctly crossing DST boundary. Closes #7399 [sblackstone]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9221 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 56 insertions, 2 deletions

diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index 587cb28522..b2955ab69d 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Time #yesterday and #tomorrow behave correctly crossing DST boundary. Closes #7399 [sblackstone]
+
 * TimeWithZone: Adding tests for dst and leap day edge cases when advancing time [Geoff Buesing]
 
 * TimeWithZone#method_missing: send to utc to advance with dst correctness, otherwise send to time. Adding tests for time calculations methods [Geoff Buesing]
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index 867ac86617..0bc83af709 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -221,12 +221,12 @@ module ActiveSupport #:nodoc:
 
         # Convenience method which returns a new Time representing the time 1 day ago
         def yesterday
-          self.ago(1.day)
+          advance(:days => -1)
         end
 
         # Convenience method which returns a new Time representing the time 1 day since the instance time
         def tomorrow
-          self.since(1.day)
+          advance(:days => 1)
         end
 
         def plus_with_duration(other) #:nodoc:
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index fd5ca5aa55..d1d92964c3 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -227,6 +227,32 @@ class TimeExtCalculationsTest < Test::Unit::TestCase
     end
   end
 
+  def test_daylight_savings_time_crossings_forward_start_tomorrow
+    with_env_tz 'US/Eastern' do
+      # st: US: 2005 April 2nd 7:27pm
+      assert_equal Time.local(2005,4,3,19,27,0), Time.local(2005,4,2,19,27,0).tomorrow, 'st+1.day=>dt'
+      assert_equal Time.local(2005,4,4,19,27,0), Time.local(2005,4,3,19,27,0).tomorrow, 'dt+1.day=>dt'
+    end
+    with_env_tz 'NZ' do
+      # st: New Zealand: 2006 September 30th 7:27pm
+      assert_equal Time.local(2006,10,1,19,27,0), Time.local(2006,9,30,19,27,0).tomorrow, 'st+1.day=>dt'
+      assert_equal Time.local(2006,10,2,19,27,0), Time.local(2006,10,1,19,27,0).tomorrow, 'dt+1.day=>dt'
+    end
+  end
+
+  def test_daylight_savings_time_crossings_forward_start_yesterday
+    with_env_tz 'US/Eastern' do
+      # st: US: 2005 April 2nd 7:27pm
+      assert_equal Time.local(2005,4,2,19,27,0), Time.local(2005,4,3,19,27,0).yesterday, 'dt-1.day=>st'
+      assert_equal Time.local(2005,4,3,19,27,0), Time.local(2005,4,4,19,27,0).yesterday, 'dt-1.day=>dt'
+    end
+    with_env_tz 'NZ' do
+      # st: New Zealand: 2006 September 30th 7:27pm
+      assert_equal Time.local(2006,9,30,19,27,0), Time.local(2006,10,1,19,27,0).yesterday, 'dt-1.day=>st'
+      assert_equal Time.local(2006,10,1,19,27,0), Time.local(2006,10,2,19,27,0).yesterday, 'dt-1.day=>dt'
+    end
+  end
+
   def test_daylight_savings_time_crossings_forward_end
     with_env_tz 'US/Eastern' do
       # dt: US: 2005 October 30th 12:45am
@@ -240,6 +266,32 @@ class TimeExtCalculationsTest < Test::Unit::TestCase
     end
   end
 
+  def test_daylight_savings_time_crossings_forward_end_tomorrow
+    with_env_tz 'US/Eastern' do
+      # dt: US: 2005 October 30th 12:45am
+      assert_equal Time.local(2005,10,31,0,45,0), Time.local(2005,10,30,0,45,0).tomorrow, 'dt+1.day=>st'
+      assert_equal Time.local(2005,11, 1,0,45,0), Time.local(2005,10,31,0,45,0).tomorrow, 'st+1.day=>st'
+    end
+    with_env_tz 'NZ' do
+      # dt: New Zealand: 2006 March 19th 1:45am
+      assert_equal Time.local(2006,3,20,1,45,0), Time.local(2006,3,19,1,45,0).tomorrow, 'dt+1.day=>st'
+      assert_equal Time.local(2006,3,21,1,45,0), Time.local(2006,3,20,1,45,0).tomorrow, 'st+1.day=>st'
+    end
+  end
+
+  def test_daylight_savings_time_crossings_forward_end_yesterday
+    with_env_tz 'US/Eastern' do
+      # dt: US: 2005 October 30th 12:45am
+      assert_equal Time.local(2005,10,30,0,45,0), Time.local(2005,10,31,0,45,0).yesterday, 'st-1.day=>dt'
+      assert_equal Time.local(2005,10, 31,0,45,0), Time.local(2005,11,1,0,45,0).yesterday, 'st-1.day=>st'
+    end
+    with_env_tz 'NZ' do
+      # dt: New Zealand: 2006 March 19th 1:45am
+      assert_equal Time.local(2006,3,19,1,45,0), Time.local(2006,3,20,1,45,0).yesterday, 'st-1.day=>dt'
+      assert_equal Time.local(2006,3,20,1,45,0), Time.local(2006,3,21,1,45,0).yesterday, 'st-1.day=>st'
+    end
+  end
+
   def test_yesterday
     assert_equal Time.local(2005,2,21,10,10,10), Time.local(2005,2,22,10,10,10).yesterday
     assert_equal Time.local(2005,2,28,10,10,10), Time.local(2005,3,2,10,10,10).yesterday.yesterday