Add some tests.

test/t/comparable.rb

@@ -54,3 +54,18 @@ def <=>(x)
   (Foo.new >= Foo.new) == true
 end
 
+assert('Comparable#between?', '15.3.3.2.6') do
+  class Foo
+    include Comparable
+    def <=>(x)
+      x
+    end
+  end
+
+  c = Foo.new
+  c.between?(-1,  1) == false &&
+  c.between?(-1, -1) == false &&
+  c.between?( 1,  1) == false &&
+  c.between?( 1, -1) == true &&
+  c.between?(0, 0) == true
+end

test/t/kernel.rb

@@ -155,6 +155,16 @@ def a.test
   a.set(2)
   c = a.clone
 
+  immutables = [ 1, :foo, true, false, nil ]
+  error_count = 0
+  immutables.each do |i|
+    begin
+      i.clone
+    rescue TypeError
+      error_count += 1
+    end
+  end
+
   a.get == 2 and b.get == 1 and c.get == 2 &&
     a.respond_to?(:test) == true and
     b.respond_to?(:test) == false and
@@ -185,7 +195,18 @@ def a.test
   a.set(2)
   c = a.dup
 
-  a.get == 2 and b.get == 1 and c.get == 2 and
+  immutables = [ 1, :foo, true, false, nil ]
+  error_count = 0
+  immutables.each do |i|
+    begin
+      i.dup
+    rescue TypeError
+      error_count += 1
+    end
+  end
+
+  error_count == immutables.size and
+    a.get == 2 and b.get == 1 and c.get == 2 and
     a.respond_to?(:test) == true and
     b.respond_to?(:test) == false and
     c.respond_to?(:test) == false

test/t/module.rb

@@ -297,6 +297,29 @@ def hello
   not Test4RemoveMethod::Child.instance_methods(false).include? :hello
 end
 
+assert('Module.undef_method', '15.2.2.4.42') do
+  module Test4UndefMethod
+    class Parent
+      def hello
+      end
+     end
+
+     class Child < Parent
+      def hello
+      end
+     end
+
+     class GrandChild < Child
+     end
+  end
+
+  Test4UndefMethod::Child.class_eval{ undef_method :hello }
+
+  Test4UndefMethod::Parent.new.respond_to?(:hello) and
+  not Test4UndefMethod::Child.new.respond_to?(:hello) and
+  not Test4UndefMethod::GrandChild.new.respond_to?(:hello)
+end
+
 
 # Not ISO specified