1 files changed, 24 insertions, 2 deletions
diff --git a/spec/ruby/core/string/equal_value_spec.rb b/spec/ruby/core/string/equal_value_spec.rb
index b9c9c372f8..e8b706c524 100644
--- a/spec/ruby/core/string/equal_value_spec.rb
+++ b/spec/ruby/core/string/equal_value_spec.rb
@@ -1,8 +1,30 @@
 require_relative '../../spec_helper'
 require_relative 'shared/eql'
-require_relative 'shared/equal_value'
 
 describe "String#==" do
   it_behaves_like :string_eql_value, :==
-  it_behaves_like :string_equal_value, :==
+
+  it "returns false if obj does not respond to to_str" do
+    ('hello' == 5).should == false
+    not_supported_on :opal do
+      ('hello' == :hello).should == false
+    end
+    ('hello' == mock('x')).should == false
+  end
+
+  it "returns obj == self if obj responds to to_str" do
+    obj = Object.new
+
+    # String#== merely checks if #to_str is defined. It does
+    # not call it.
+    obj.stub!(:to_str)
+
+    obj.should_receive(:==).and_return(true)
+
+    ('hello' == obj).should == true
+  end
+
+  it "is not fooled by NUL characters" do
+    ("abc\0def" == "abc\0xyz").should == false
+  end
 end