1 files changed, 31 insertions, 11 deletions
diff --git a/spec/ruby/core/string/reverse_spec.rb b/spec/ruby/core/string/reverse_spec.rb
index eef46063a5..e37c1125db 100644
--- a/spec/ruby/core/string/reverse_spec.rb
+++ b/spec/ruby/core/string/reverse_spec.rb
@@ -1,4 +1,5 @@
 # encoding: utf-8
+# frozen_string_literal: false
 
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
@@ -10,36 +11,46 @@ describe "String#reverse" do
     "".reverse.should == ""
   end
 
-  ruby_version_is ''...'2.7' do
-    it "taints the result if self is tainted" do
-      "".taint.reverse.tainted?.should == true
-      "m".taint.reverse.tainted?.should == true
-    end
+  it "returns String instances when called on a subclass" do
+    StringSpecs::MyString.new("stressed").reverse.should.instance_of?(String)
+    StringSpecs::MyString.new("m").reverse.should.instance_of?(String)
+    StringSpecs::MyString.new("").reverse.should.instance_of?(String)
   end
 
   it "reverses a string with multi byte characters" do
     "微軟正黑體".reverse.should == "體黑正軟微"
   end
 
+  it "works with a broken string" do
+    str = "微軟\xDF\xDE正黑體".force_encoding(Encoding::UTF_8)
+
+    str.valid_encoding?.should == false
+
+    str.reverse.should == "體黑正\xDE\xDF軟微"
+  end
+
+  it "returns a String in the same encoding as self" do
+    "stressed".encode("US-ASCII").reverse.encoding.should == Encoding::US_ASCII
+  end
 end
 
 describe "String#reverse!" do
   it "reverses self in place and always returns self" do
     a = "stressed"
-    a.reverse!.should equal(a)
+    a.reverse!.should.equal?(a)
     a.should == "desserts"
 
     "".reverse!.should == ""
   end
 
-  it "raises a #{frozen_error_class} on a frozen instance that is modified" do
-    -> { "anna".freeze.reverse!  }.should raise_error(frozen_error_class)
-    -> { "hello".freeze.reverse! }.should raise_error(frozen_error_class)
+  it "raises a FrozenError on a frozen instance that is modified" do
+    -> { "anna".freeze.reverse!  }.should.raise(FrozenError)
+    -> { "hello".freeze.reverse! }.should.raise(FrozenError)
   end
 
   # see [ruby-core:23666]
-  it "raises a #{frozen_error_class} on a frozen instance that would not be modified" do
-    -> { "".freeze.reverse! }.should raise_error(frozen_error_class)
+  it "raises a FrozenError on a frozen instance that would not be modified" do
+    -> { "".freeze.reverse! }.should.raise(FrozenError)
   end
 
   it "reverses a string with multi byte characters" do
@@ -47,4 +58,13 @@ describe "String#reverse!" do
     str.reverse!
     str.should == "體黑正軟微"
   end
+
+  it "works with a broken string" do
+    str = "微軟\xDF\xDE正黑體".force_encoding(Encoding::UTF_8)
+
+    str.valid_encoding?.should == false
+    str.reverse!
+
+    str.should == "體黑正\xDE\xDF軟微"
+  end
 end