1 files changed, 29 insertions, 25 deletions
diff --git a/spec/ruby/core/string/scrub_spec.rb b/spec/ruby/core/string/scrub_spec.rb
index 3137399291..9dc55dbef7 100644
--- a/spec/ruby/core/string/scrub_spec.rb
+++ b/spec/ruby/core/string/scrub_spec.rb
@@ -1,4 +1,5 @@
 # -*- encoding: utf-8 -*-
+# frozen_string_literal: false
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 
@@ -14,6 +15,11 @@ describe "String#scrub with a default replacement" do
     "abc\u3042#{x81}".scrub.should == "abc\u3042\uFFFD"
   end
 
+  it "replaces invalid byte sequences in lazy substrings" do
+    x81 = [0x81].pack('C').force_encoding('utf-8')
+    "abc\u3042#{x81}def"[1...-1].scrub.should == "bc\u3042\uFFFDde"
+  end
+
   it "returns a copy of self when the input encoding is BINARY" do
     input = "foo".encode('BINARY')
 
@@ -26,18 +32,15 @@ describe "String#scrub with a default replacement" do
     input.scrub.should == "abc?????"
   end
 
-  ruby_version_is '3.0' do
-    it "returns String instances when called on a subclass" do
-      StringSpecs::MyString.new("foo").scrub.should be_an_instance_of(String)
-      input = [0x81].pack('C').force_encoding('utf-8')
-      StringSpecs::MyString.new(input).scrub.should be_an_instance_of(String)
-    end
+  it "returns a String in the same encoding as self" do
+    x81 = [0x81].pack('C').force_encoding('utf-8')
+    "abc\u3042#{x81}".scrub.encoding.should == Encoding::UTF_8
   end
 
-  ruby_version_is ''...'3.0' do
-    it "returns subclass instances when called on a subclass" do
-      StringSpecs::MyString.new("foo").scrub.should be_an_instance_of(StringSpecs::MyString)
-    end
+  it "returns String instances when called on a subclass" do
+    StringSpecs::MyString.new("foo").scrub.should.instance_of?(String)
+    input = [0x81].pack('C').force_encoding('utf-8')
+    StringSpecs::MyString.new(input).scrub.should.instance_of?(String)
   end
 end
 
@@ -72,22 +75,25 @@ describe "String#scrub with a custom replacement" do
     xE4 = [0xE4].pack('C').force_encoding('utf-8')
     block = -> { "foo#{x81}".scrub(xE4) }
 
-    block.should raise_error(ArgumentError)
+    block.should.raise(ArgumentError)
+  end
+
+  it "returns a String in the same encoding as self" do
+    x81 = [0x81].pack('C').force_encoding('utf-8')
+    "abc\u3042#{x81}".scrub("*").encoding.should == Encoding::UTF_8
   end
 
   it "raises TypeError when a non String replacement is given" do
     x81 = [0x81].pack('C').force_encoding('utf-8')
     block = -> { "foo#{x81}".scrub(1) }
 
-    block.should raise_error(TypeError)
+    block.should.raise(TypeError)
   end
 
-  ruby_version_is '3.0' do
-    it "returns String instances when called on a subclass" do
-      StringSpecs::MyString.new("foo").scrub("*").should be_an_instance_of(String)
-      input = [0x81].pack('C').force_encoding('utf-8')
-      StringSpecs::MyString.new(input).scrub("*").should be_an_instance_of(String)
-    end
+  it "returns String instances when called on a subclass" do
+    StringSpecs::MyString.new("foo").scrub("*").should.instance_of?(String)
+    input = [0x81].pack('C').force_encoding('utf-8')
+    StringSpecs::MyString.new(input).scrub("*").should.instance_of?(String)
   end
 end
 
@@ -114,12 +120,10 @@ describe "String#scrub with a block" do
     replaced.should == "€€"
   end
 
-  ruby_version_is '3.0' do
-    it "returns String instances when called on a subclass" do
-      StringSpecs::MyString.new("foo").scrub { |b| "*" }.should be_an_instance_of(String)
-      input = [0x81].pack('C').force_encoding('utf-8')
-      StringSpecs::MyString.new(input).scrub { |b| "<#{b.unpack("H*")[0]}>" }.should be_an_instance_of(String)
-    end
+  it "returns String instances when called on a subclass" do
+    StringSpecs::MyString.new("foo").scrub { |b| "*" }.should.instance_of?(String)
+    input = [0x81].pack('C').force_encoding('utf-8')
+    StringSpecs::MyString.new(input).scrub { |b| "<#{b.unpack("H*")[0]}>" }.should.instance_of?(String)
   end
 end
 
@@ -142,7 +146,7 @@ describe "String#scrub!" do
     input = "a"
     input.freeze
     input.scrub!
-    input.frozen?.should be_true
+    input.frozen?.should == true
   end
 
   it "preserves the instance variables of already valid strings" do