Merge pull request #7350 from slbug/date_time_ranges_with_infinite_bounds

Added ability to compare date/time with infinity

activesupport/CHANGELOG.md

 ## Rails 4.0.0 (unreleased) ##
 
+*   It's now possible to compare Date, DateTime, Time and TimeWithZone with Infinity
+    This allows to create date/time ranges with one infinite bound.
+    Example:
+
+        range = Range.new(Date.today, Float::INFINITY)
+
+    Also it's possible to check inclusion of date/time in range with conversion.
+
+        range.include?(Time.now + 1.year)     # => true
+        range.include?(DateTime.now + 1.year) # => true
+
+    *Alexander Grebennik*
+
 *   Remove meaningless `ActiveSupport::FrozenObjectError`, which was just an alias of `RuntimeError`.
 
     *Akira Matsuda*

activesupport/lib/active_support/core_ext/date.rb

@@ -2,4 +2,5 @@
 require 'active_support/core_ext/date/calculations'
 require 'active_support/core_ext/date/conversions'
 require 'active_support/core_ext/date/zones'
+require 'active_support/core_ext/date/infinite_comparable'
 

activesupport/lib/active_support/core_ext/date/infinite_comparable.rb

+require 'active_support/core_ext/infinite_comparable'
+
+class Date
+  include InfiniteComparable
+end

activesupport/lib/active_support/core_ext/date_time.rb

@@ -2,3 +2,4 @@
 require 'active_support/core_ext/date_time/calculations'
 require 'active_support/core_ext/date_time/conversions'
 require 'active_support/core_ext/date_time/zones'
+require 'active_support/core_ext/date_time/infinite_comparable'

activesupport/lib/active_support/core_ext/date_time/calculations.rb

@@ -142,11 +142,4 @@ def utc?
   def utc_offset
     (offset * 86400).to_i
   end
-
-  # Layers additional behavior on DateTime#<=> so that Time and
-  # ActiveSupport::TimeWithZone instances can be compared with a DateTime.
-  def <=>(other)
-    super other.to_datetime
-  end
-
 end

activesupport/lib/active_support/core_ext/date_time/infinite_comparable.rb

+require 'active_support/core_ext/infinite_comparable'
+
+class DateTime
+  include InfiniteComparable
+end

activesupport/lib/active_support/core_ext/infinite_comparable.rb

+require 'active_support/concern'
+
+module InfiniteComparable
+  extend ActiveSupport::Concern
+
+  included do
+    alias_method_chain :<=>, :infinity
+  end
+
+  define_method '<=>_with_infinity' do |other|
+    if other.class == self.class
+      self.send(:'<=>_without_infinity', other)
+    # inf <=> inf
+    elsif other.respond_to?(:infinite?) && other.infinite? && respond_to?(:infinite?) && infinite?
+      infinite? <=> other.infinite?
+    # not_inf <=> inf
+    elsif other.respond_to?(:infinite?) && other.infinite?
+      -other.infinite?
+    # inf <=> not_inf
+    elsif respond_to?(:infinite?) && infinite?
+      infinite?
+    else
+      conversion = :"to_#{self.class.name.downcase}"
+
+      other = other.send(conversion) if other.respond_to?(conversion)
+
+      self.send(:'<=>_without_infinity', other)
+    end
+  end
+end

activesupport/lib/active_support/core_ext/numeric.rb

 require 'active_support/core_ext/numeric/bytes'
 require 'active_support/core_ext/numeric/time'
 require 'active_support/core_ext/numeric/conversions'
+require 'active_support/core_ext/numeric/infinite_comparable'

activesupport/lib/active_support/core_ext/numeric/infinite_comparable.rb

+require 'active_support/core_ext/big_decimal/conversions'
+require 'active_support/number_helper'
+require 'active_support/core_ext/infinite_comparable'
+
+class Float
+  include InfiniteComparable
+end
+
+class BigDecimal
+  include InfiniteComparable
+end

activesupport/lib/active_support/core_ext/time.rb

@@ -3,3 +3,4 @@
 require 'active_support/core_ext/time/conversions'
 require 'active_support/core_ext/time/marshal'
 require 'active_support/core_ext/time/zones'
+require 'active_support/core_ext/time/infinite_comparable'

activesupport/lib/active_support/core_ext/time/infinite_comparable.rb

+require 'active_support/core_ext/infinite_comparable'
+
+class Time
+  include InfiniteComparable
+end

activesupport/test/core_ext/date_ext_test.rb

@@ -353,6 +353,13 @@ def test_can_freeze_twice
       Date.today.freeze.freeze
     end
   end
+
+  def test_compare_with_infinity
+    assert_nothing_raised do
+      assert_equal(-1, Date.today <=> Float::INFINITY)
+      assert_equal(1, Date.today <=> -Float::INFINITY)
+    end
+  end
 end
 
 class DateExtConversionsTest < ActiveSupport::TestCase

activesupport/test/core_ext/date_time_ext_test.rb

@@ -317,3 +317,12 @@ def with_env_tz(new_tz = 'US/Eastern')
       old_tz ? ENV['TZ'] = old_tz : ENV.delete('TZ')
     end
 end
+
+class DateTimeExtBehaviorTest < ActiveSupport::TestCase
+  def test_compare_with_infinity
+    assert_nothing_raised do
+      assert_equal(-1, DateTime.now <=> Float::INFINITY)
+      assert_equal(1, DateTime.now <=> -Float::INFINITY)
+    end
+  end
+end

activesupport/test/core_ext/numeric_ext_test.rb

@@ -447,3 +447,67 @@ def test_to_s__injected_on_proper_types
     assert_equal '1 Million', BigDecimal("1000010").to_s(:human)
   end
 end
+
+class NumericExtBehaviorTest < ActiveSupport::TestCase
+  def setup
+    @inf = BigDecimal.new('Infinity')
+  end
+
+  def test_compare_infinity_with_date
+    assert_nothing_raised do
+      assert_equal(-1, -Float::INFINITY <=> Date.today)
+      assert_equal(1, Float::INFINITY <=> Date.today)
+      assert_equal(-1, -@inf <=> Date.today)
+      assert_equal(1, @inf <=> Date.today)
+    end
+  end
+
+  def test_compare_infinty_with_infinty
+    assert_nothing_raised do
+      assert_equal(-1, -Float::INFINITY <=> Float::INFINITY)
+      assert_equal(1, Float::INFINITY <=> -Float::INFINITY)
+      assert_equal(0, Float::INFINITY <=> Float::INFINITY)
+      assert_equal(0, -Float::INFINITY <=> -Float::INFINITY)
+
+      assert_equal(-1, -Float::INFINITY <=> BigDecimal::INFINITY)
+      assert_equal(1, Float::INFINITY <=> -BigDecimal::INFINITY)
+      assert_equal(0, Float::INFINITY <=> BigDecimal::INFINITY)
+      assert_equal(0, -Float::INFINITY <=> -BigDecimal::INFINITY)
+
+      assert_equal(-1, -BigDecimal::INFINITY <=> Float::INFINITY)
+      assert_equal(1, BigDecimal::INFINITY <=> -Float::INFINITY)
+      assert_equal(0, BigDecimal::INFINITY <=> Float::INFINITY)
+      assert_equal(0, -BigDecimal::INFINITY <=> -Float::INFINITY)
+    end
+  end
+
+  def test_compare_infinity_with_time
+    assert_nothing_raised do
+      assert_equal(-1, -Float::INFINITY <=> Time.now)
+      assert_equal(1, Float::INFINITY <=> Time.now)
+      assert_equal(-1, -@inf <=> Time.now)
+      assert_equal(1, @inf <=> Time.now)
+    end
+  end
+
+  def test_compare_infinity_with_datetime
+    assert_nothing_raised do
+      assert_equal(-1, -Float::INFINITY <=> DateTime.now)
+      assert_equal(1, Float::INFINITY <=> DateTime.now)
+      assert_equal(-1, -@inf <=> DateTime.now)
+      assert_equal(1, @inf <=> DateTime.now)
+    end
+  end
+
+  def test_compare_infinity_with_twz
+    time_zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+    twz = ActiveSupport::TimeWithZone.new(Time.now, time_zone)
+
+    assert_nothing_raised do
+      assert_equal(-1, -Float::INFINITY <=> twz)
+      assert_equal(1, Float::INFINITY <=> twz)
+      assert_equal(-1, -@inf <=> twz)
+      assert_equal(1, @inf <=> twz)
+    end
+  end
+end

activesupport/test/core_ext/range_ext_test.rb

 require 'abstract_unit'
 require 'active_support/time'
 require 'active_support/core_ext/range'
+require 'active_support/core_ext/numeric'
 
 class RangeTest < ActiveSupport::TestCase
   def test_to_s_from_dates
@@ -85,4 +86,28 @@ def test_no_overlaps_on_time
     time_range_2 = Time.utc(2005, 12, 10, 17, 31)..Time.utc(2005, 12, 10, 18, 00)
     assert !time_range_1.overlaps?(time_range_2)
   end
+
+  def test_infinite_bounds
+    time_zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+
+    time = Time.now
+    date = Date.today
+    datetime = DateTime.now
+    twz = ActiveSupport::TimeWithZone.new(time, time_zone)
+
+    infinity1 = Float::INFINITY
+    infinity2 = BigDecimal.new('Infinity')
+
+    [infinity1, infinity2].each do |infinity|
+      [time, date, datetime, twz].each do |bound|
+        [time, date, datetime, twz].each do |value|
+          assert Range.new(bound, infinity).include?(value + 10.years)
+          assert Range.new(-infinity, bound).include?(value - 10.years)
+
+          assert !Range.new(bound, infinity).include?(value - 10.years)
+          assert !Range.new(-infinity, bound).include?(value + 10.years)
+        end
+      end
+    end
+  end
 end

activesupport/test/core_ext/time_ext_test.rb

@@ -843,3 +843,12 @@ def test_last_quarter_on_31st
     assert_equal Time.local(2004, 2, 29), Time.local(2004, 5, 31).last_quarter
   end
 end
+
+class TimeExtBehaviorTest < ActiveSupport::TestCase
+  def test_compare_with_infinity
+    assert_nothing_raised do
+      assert_equal(-1, Time.now <=> Float::INFINITY)
+      assert_equal(1, Time.now <=> -Float::INFINITY)
+    end
+  end
+end

activesupport/test/core_ext/time_with_zone_test.rb

@@ -1081,3 +1081,15 @@ def with_tz_default(tz = nil)
       Time.zone = old_tz
     end
 end
+
+class TimeWithZoneExtBehaviorTest < ActiveSupport::TestCase
+  def test_compare_with_infinity
+    time_zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+    twz = ActiveSupport::TimeWithZone.new(Time.now, time_zone)
+
+    assert_nothing_raised do
+      assert_equal(-1, twz <=> Float::INFINITY)
+      assert_equal(1, twz <=> -Float::INFINITY)
+    end
+  end
+end