Add Date#next_year and Date#prev_year

See ruby-doc.org/stdlib-2.5.0/libdoc/date/rdoc/Date.html#method-i-next_year
opal · Sep 12, 2018 · e5d2534 · e5d2534
1 parent f21e5bc
commit e5d2534
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Showing 2 changed files with 15 additions and 2 deletions.
diff --git a/spec/filters/bugs/date.rb b/spec/filters/bugs/date.rb
@@ -23,11 +23,9 @@
   fails "Date#mjd determines the Modified Julian day"
   fails "Date#mon determines the month"
   fails "Date#new_start converts a date object into another with a new calendar reform"
-  fails "Date#next_year returns the day of the reform if date falls within calendar reform"
   fails "Date#parse parses a day name into a Date object"
   fails "Date#parse parses a month day into a Date object"
   fails "Date#parse parses a month name into a Date object"
-  fails "Date#prev_year returns the day of the reform if date falls within calendar reform"
   fails "Date#strftime should be able to print the commercial year with leading zeroes"
   fails "Date#strftime should be able to print the commercial year with only two digits"
   fails "Date#strftime should be able to print the julian day with leading zeroes"

diff --git a/stdlib/date.rb b/stdlib/date.rb
@@ -347,6 +347,13 @@ def gregorian_leap?(year)
   end
 
   def initialize(year = -4712, month = 1, day = 1, start = ITALY)
+    %x{
+      // Because of Gregorian reform calendar goes from 1582-10-04 to 1582-10-15.
+      // All days in between end up as 4 october.
+      if (year === 1582 && month === 10 && day > 4 && day < 15) {
+        day = 4;
+      }
+    }
     @date = `new Date(year, month - 1, day)`
   end
 
@@ -545,6 +552,10 @@ def next_month(n = 1)
     }
   end
 
+  def next_year(years = 1)
+    self.class.new(year + years, month, day)
+  end
+
   def prev_day(n = 1)
     self - n
   end
@@ -559,6 +570,10 @@ def prev_month(n = 1)
     }
   end
 
+  def prev_year(years = 1)
+    self.class.new(year - years, month, day)
+  end
+
   def saturday?
     wday == 6
   end