1 files changed, 23 insertions, 0 deletions
diff --git a/spec/ruby/library/date/minus_month_spec.rb b/spec/ruby/library/date/minus_month_spec.rb
new file mode 100644
index 0000000000..d56e19dc31
--- /dev/null
+++ b/spec/ruby/library/date/minus_month_spec.rb
@@ -0,0 +1,23 @@
+require 'date'
+require_relative '../../spec_helper'
+
+describe "Date#<<" do
+
+  it "subtracts a number of months from a date" do
+    d = Date.civil(2007,2,27) << 10
+    d.should == Date.civil(2006, 4, 27)
+  end
+
+  it "returns the last day of a month if the day doesn't exist" do
+    d = Date.civil(2008,3,31) << 1
+    d.should == Date.civil(2008, 2, 29)
+  end
+
+  it "raises an error on non numeric parameters" do
+    -> { Date.civil(2007,2,27) << :hello }.should.raise(TypeError)
+    -> { Date.civil(2007,2,27) << "hello" }.should.raise(TypeError)
+    -> { Date.civil(2007,2,27) << Date.new }.should.raise(TypeError)
+    -> { Date.civil(2007,2,27) << Object.new }.should.raise(TypeError)
+  end
+
+end