Merge pull request #27610 from Envek/fix_and_speed_up_duration_parsing

Fix inconsistent parsing of Durations with both months and years

3 files changed, 26 insertions, 15 deletions

diff --git a/activesupport/lib/active_support/core_ext/integer/time.rb b/activesupport/lib/active_support/core_ext/integer/time.rb
index 4a64872392..66ac3ca1b4 100644
--- a/activesupport/lib/active_support/core_ext/integer/time.rb
+++ b/activesupport/lib/active_support/core_ext/integer/time.rb
@@ -18,12 +18,12 @@ class Integer
   #   # equivalent to Time.now.advance(months: 4, years: 5)
   #   (4.months + 5.years).from_now
   def months
-    ActiveSupport::Duration.new(self * 30.days, [[:months, self]])
+    ActiveSupport::Duration.new(self * ActiveSupport::Duration::PARTS_IN_SECONDS[:months].to_i, [[:months, self]])
   end
   alias :month :months
 
   def years
-    ActiveSupport::Duration.new(self * 365.25.days.to_i, [[:years, self]])
+    ActiveSupport::Duration.new(self * ActiveSupport::Duration::PARTS_IN_SECONDS[:years].to_i, [[:years, self]])
   end
   alias :year :years
 end
diff --git a/activesupport/lib/active_support/core_ext/numeric/time.rb b/activesupport/lib/active_support/core_ext/numeric/time.rb
index 809dfd4e07..6ca2468047 100644
--- a/activesupport/lib/active_support/core_ext/numeric/time.rb
+++ b/activesupport/lib/active_support/core_ext/numeric/time.rb
@@ -27,7 +27,7 @@ class Numeric
   #
   #   2.minutes # => 2 minutes
   def minutes
-    ActiveSupport::Duration.new(self * 60, [[:minutes, self]])
+    ActiveSupport::Duration.new(self * ActiveSupport::Duration::PARTS_IN_SECONDS[:minutes], [[:minutes, self]])
   end
   alias :minute :minutes
 
@@ -35,7 +35,7 @@ class Numeric
   #
   #   2.hours # => 2 hours
   def hours
-    ActiveSupport::Duration.new(self * 3600, [[:hours, self]])
+    ActiveSupport::Duration.new(self * ActiveSupport::Duration::PARTS_IN_SECONDS[:hours], [[:hours, self]])
   end
   alias :hour :hours
 
@@ -43,7 +43,7 @@ class Numeric
   #
   #   2.days # => 2 days
   def days
-    ActiveSupport::Duration.new(self * 24.hours, [[:days, self]])
+    ActiveSupport::Duration.new(self * ActiveSupport::Duration::PARTS_IN_SECONDS[:days], [[:days, self]])
   end
   alias :day :days
 
@@ -51,7 +51,7 @@ class Numeric
   #
   #   2.weeks # => 2 weeks
   def weeks
-    ActiveSupport::Duration.new(self * 7.days, [[:weeks, self]])
+    ActiveSupport::Duration.new(self * ActiveSupport::Duration::PARTS_IN_SECONDS[:weeks], [[:weeks, self]])
   end
   alias :week :weeks
 
@@ -59,7 +59,7 @@ class Numeric
   #
   #   2.fortnights # => 4 weeks
   def fortnights
-    ActiveSupport::Duration.new(self * 2.weeks, [[:weeks, self * 2]])
+    ActiveSupport::Duration.new(self * 2 * ActiveSupport::Duration::PARTS_IN_SECONDS[:weeks], [[:weeks, self * 2]])
   end
   alias :fortnight :fortnights
 
diff --git a/activesupport/lib/active_support/duration.rb b/activesupport/lib/active_support/duration.rb
index c9e8c8fdc4..71b6001503 100644
--- a/activesupport/lib/active_support/duration.rb
+++ b/activesupport/lib/active_support/duration.rb
@@ -7,7 +7,15 @@ module ActiveSupport
   #
   #   1.month.ago       # equivalent to Time.now.advance(months: -1)
   class Duration
-    EPOCH = ::Time.utc(2000)
+    PARTS_IN_SECONDS = {
+      seconds:                               1, # Used in parse method for ease of handling part hashes with seconds
+      minutes:                              60,
+      hours:                           60 * 60,
+      days:                       24 * 60 * 60,
+      weeks:       7            * 24 * 60 * 60,
+      months:  ((365.2425 / 12) * 24 * 60 * 60).ceil, # 1 year is always 12 months long, no sense to bind it to days
+      years:    (365.2425       * 24 * 60 * 60).ceil, # Gregorian year length to account for the every 400 non-leap year
+    }.freeze
 
     attr_accessor :value, :parts
 
@@ -78,14 +86,14 @@ module ActiveSupport
     #   1.day.to_i      # => 86400
     #
     # Note that this conversion makes some assumptions about the
-    # duration of some periods, e.g. months are always 30 days
-    # and years are 365.25 days:
+    # duration of some periods, e.g. months are always 1/12 of year
+    # and years are 365.2425 days:
     #
-    #   # equivalent to 30.days.to_i
-    #   1.month.to_i    # => 2592000
+    #   # equivalent to (1.year / 12).to_i
+    #   1.month.to_i    # => 2629746
     #
-    #   # equivalent to 365.25.days.to_i
-    #   1.year.to_i     # => 31557600
+    #   # equivalent to 365.2425.days.to_i
+    #   1.year.to_i     # => 31556952
     #
     # In such cases, Ruby's core
     # Date[http://ruby-doc.org/stdlib/libdoc/date/rdoc/Date.html] and
@@ -148,7 +156,10 @@ module ActiveSupport
     # If invalid string is provided, it will raise +ActiveSupport::Duration::ISO8601Parser::ParsingError+.
     def self.parse(iso8601duration)
       parts = ISO8601Parser.new(iso8601duration).parse!
-      new(EPOCH.advance(parts) - EPOCH, parts)
+      total_seconds = parts.inject(0) do |total, (part, value)|
+        total + value * PARTS_IN_SECONDS[part]
+      end
+      new(total_seconds, parts)
     end
 
     # Build ISO 8601 Duration string for this duration.