1 files changed, 48 insertions, 0 deletions
diff --git a/spec/ruby/library/date/constants_spec.rb b/spec/ruby/library/date/constants_spec.rb
new file mode 100644
index 0000000000..3494b0c296
--- /dev/null
+++ b/spec/ruby/library/date/constants_spec.rb
@@ -0,0 +1,48 @@
+require 'date'
+require_relative '../../spec_helper'
+
+describe "Date constants" do
+
+  it "defines JULIAN" do
+    (Date::JULIAN <=> Date::Infinity.new).should == 0
+  end
+
+  it "defines GREGORIAN" do
+    (Date::GREGORIAN <=> -Date::Infinity.new).should == 0
+  end
+
+  it "defines ITALY" do
+    Date::ITALY.should == 2299161 # 1582-10-15
+  end
+
+  it "defines ENGLAND" do
+    Date::ENGLAND.should == 2361222 # 1752-09-14
+  end
+
+  it "defines MONTHNAMES" do
+    Date::MONTHNAMES.should == [nil] + %w(January February March April May June July
+                                          August September October November December)
+  end
+
+  it "defines DAYNAMES" do
+    Date::DAYNAMES.should == %w(Sunday Monday Tuesday Wednesday Thursday Friday Saturday)
+  end
+
+  it "defines ABBR_MONTHNAMES" do
+    Date::ABBR_DAYNAMES.should == %w(Sun Mon Tue Wed Thu Fri Sat)
+  end
+
+  it "freezes MONTHNAMES, DAYNAMES, ABBR_MONTHNAMES, ABBR_DAYSNAMES" do
+    [Date::MONTHNAMES, Date::DAYNAMES, Date::ABBR_MONTHNAMES, Date::ABBR_DAYNAMES].each do |ary|
+      -> {
+        ary << "Unknown"
+      }.should.raise(FrozenError, /frozen/)
+      ary.compact.each do |name|
+        -> {
+          name << "modified"
+        }.should.raise(FrozenError, /frozen/)
+      end
+    end
+  end
+
+end