1 files changed, 31 insertions, 0 deletions
diff --git a/spec/ruby/core/module/case_compare_spec.rb b/spec/ruby/core/module/case_compare_spec.rb
new file mode 100644
index 0000000000..49ac359f6f
--- /dev/null
+++ b/spec/ruby/core/module/case_compare_spec.rb
@@ -0,0 +1,31 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Module#===" do
+  it "returns true when the given Object is an instance of self or of self's descendants" do
+    (ModuleSpecs::Child       === ModuleSpecs::Child.new).should == true
+    (ModuleSpecs::Parent      === ModuleSpecs::Parent.new).should == true
+
+    (ModuleSpecs::Parent      === ModuleSpecs::Child.new).should == true
+    (Object                   === ModuleSpecs::Child.new).should == true
+
+    (ModuleSpecs::Child       === String.new).should == false
+    (ModuleSpecs::Child       === mock('x')).should == false
+  end
+
+  it "returns true when the given Object's class includes self or when the given Object is extended by self" do
+    (ModuleSpecs::Basic === ModuleSpecs::Child.new).should == true
+    (ModuleSpecs::Super === ModuleSpecs::Child.new).should == true
+    (ModuleSpecs::Basic === mock('x').extend(ModuleSpecs::Super)).should == true
+    (ModuleSpecs::Super === mock('y').extend(ModuleSpecs::Super)).should == true
+
+    (ModuleSpecs::Basic === ModuleSpecs::Parent.new).should == false
+    (ModuleSpecs::Super === ModuleSpecs::Parent.new).should == false
+    (ModuleSpecs::Basic === mock('z')).should == false
+    (ModuleSpecs::Super === mock('a')).should == false
+  end
+
+  it "does not let a module singleton class interfere when its on the RHS" do
+    (Class === ModuleSpecs::CaseCompareOnSingleton).should == false
+  end
+end