Move helper methods to helper.rb. Make test not depend on local TZ to…

… pass or fail.

Signed-off-by: José Valim <jose.valim@gmail.com>

activerecord/test/cases/date_time_test.rb

@@ -4,17 +4,21 @@
 
 class DateTimeTest < ActiveRecord::TestCase
   def test_saves_both_date_and_time
-    time_values = [1807, 2, 10, 15, 30, 45]
-    # create DateTime value with local time zone offset
-    local_offset = Rational(Time.local_time(*time_values).utc_offset, 86400)
-    now = DateTime.civil(*(time_values + [local_offset]))
+    with_env_tz 'America/New_York' do
+      with_active_record_default_timezone :utc do
+        time_values = [1807, 2, 10, 15, 30, 45]
+        # create DateTime value with local time zone offset
+        local_offset = Rational(Time.local_time(*time_values).utc_offset, 86400)
+        now = DateTime.civil(*(time_values + [local_offset]))
 
-    task = Task.new
-    task.starting = now
-    task.save!
+        task = Task.new
+        task.starting = now
+        task.save!
 
-    # check against Time.local_time, since some platforms will return a Time instead of a DateTime
-    assert_equal Time.local_time(*time_values), Task.find(task.id).starting
+        # check against Time.local_time, since some platforms will return a Time instead of a DateTime
+        assert_equal Time.local_time(*time_values), Task.find(task.id).starting
+      end
+    end
   end
 
   def test_assign_empty_date_time

activerecord/test/cases/helper.rb

@@ -31,6 +31,20 @@ def current_adapter?(*types)
   end
 end
 
+def with_env_tz(new_tz = 'US/Eastern')
+  old_tz, ENV['TZ'] = ENV['TZ'], new_tz
+  yield
+ensure
+  old_tz ? ENV['TZ'] = old_tz : ENV.delete('TZ')
+end
+
+def with_active_record_default_timezone(zone)
+  old_zone, ActiveRecord::Base.default_timezone = ActiveRecord::Base.default_timezone, zone
+  yield
+ensure
+  ActiveRecord::Base.default_timezone = old_zone
+end
+
 ActiveRecord::Base.connection.class.class_eval do
   IGNORED_SQL = [/^PRAGMA/, /^SELECT currval/, /^SELECT CAST/, /^SELECT @@IDENTITY/, /^SELECT @@ROWCOUNT/, /^SAVEPOINT/, /^ROLLBACK TO SAVEPOINT/, /^RELEASE SAVEPOINT/, /SHOW FIELDS/]