1 files changed, 39 insertions, 18 deletions
diff --git a/spec/ruby/core/string/gsub_spec.rb b/spec/ruby/core/string/gsub_spec.rb
index 3211ebbd0a..0d9f32eca2 100644
--- a/spec/ruby/core/string/gsub_spec.rb
+++ b/spec/ruby/core/string/gsub_spec.rb
@@ -1,4 +1,5 @@
 # -*- encoding: utf-8 -*-
+# frozen_string_literal: false
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 
@@ -192,26 +193,13 @@ describe "String#gsub with pattern and replacement" do
     -> { "hello".gsub(/[aeiou]/, nil)           }.should raise_error(TypeError)
   end
 
-  ruby_version_is ''...'3.0' do
-    it "returns subclass instances when called on a subclass" do
-      StringSpecs::MyString.new("").gsub(//, "").should be_an_instance_of(StringSpecs::MyString)
-      StringSpecs::MyString.new("").gsub(/foo/, "").should be_an_instance_of(StringSpecs::MyString)
-      StringSpecs::MyString.new("foo").gsub(/foo/, "").should be_an_instance_of(StringSpecs::MyString)
-      StringSpecs::MyString.new("foo").gsub("foo", "").should be_an_instance_of(StringSpecs::MyString)
-    end
+  it "returns String instances when called on a subclass" do
+    StringSpecs::MyString.new("").gsub(//, "").should be_an_instance_of(String)
+    StringSpecs::MyString.new("").gsub(/foo/, "").should be_an_instance_of(String)
+    StringSpecs::MyString.new("foo").gsub(/foo/, "").should be_an_instance_of(String)
+    StringSpecs::MyString.new("foo").gsub("foo", "").should be_an_instance_of(String)
   end
 
-  ruby_version_is '3.0' do
-    it "returns String instances when called on a subclass" do
-      StringSpecs::MyString.new("").gsub(//, "").should be_an_instance_of(String)
-      StringSpecs::MyString.new("").gsub(/foo/, "").should be_an_instance_of(String)
-      StringSpecs::MyString.new("foo").gsub(/foo/, "").should be_an_instance_of(String)
-      StringSpecs::MyString.new("foo").gsub("foo", "").should be_an_instance_of(String)
-    end
-  end
-
-  # Note: $~ cannot be tested because mspec messes with it
-
   it "sets $~ to MatchData of last match and nil when there's none" do
     'hello.'.gsub('hello', 'x')
     $~[0].should == 'hello'
@@ -225,6 +213,18 @@ describe "String#gsub with pattern and replacement" do
     'hello.'.gsub(/not/, 'x')
     $~.should == nil
   end
+
+  it "handles a pattern in a superset encoding" do
+    result = 'abc'.force_encoding(Encoding::US_ASCII).gsub('é', 'è')
+    result.should == 'abc'
+    result.encoding.should == Encoding::US_ASCII
+  end
+
+  it "handles a pattern in a subset encoding" do
+    result = 'été'.gsub('t'.force_encoding(Encoding::US_ASCII), 'u')
+    result.should == 'éué'
+    result.encoding.should == Encoding::UTF_8
+  end
 end
 
 describe "String#gsub with pattern and Hash" do
@@ -521,6 +521,27 @@ describe "String#gsub! with pattern and replacement" do
     -> { s.gsub!(/e/, "e")       }.should raise_error(FrozenError)
     -> { s.gsub!(/[aeiou]/, '*') }.should raise_error(FrozenError)
   end
+
+  it "handles a pattern in a superset encoding" do
+    string = 'abc'.force_encoding(Encoding::US_ASCII)
+
+    result = string.gsub!('é', 'è')
+
+    result.should == nil
+    string.should == 'abc'
+    string.encoding.should == Encoding::US_ASCII
+  end
+
+  it "handles a pattern in a subset encoding" do
+    string = 'été'
+    pattern = 't'.force_encoding(Encoding::US_ASCII)
+
+    result = string.gsub!(pattern, 'u')
+
+    result.should == string
+    string.should == 'éué'
+    string.encoding.should == Encoding::UTF_8
+  end
 end
 
 describe "String#gsub! with pattern and block" do