1 files changed, 32 insertions, 81 deletions
diff --git a/spec/ruby/core/string/chomp_spec.rb b/spec/ruby/core/string/chomp_spec.rb
index b3f64d7118..3a8550892f 100644
--- a/spec/ruby/core/string/chomp_spec.rb
+++ b/spec/ruby/core/string/chomp_spec.rb
@@ -1,4 +1,5 @@
 # -*- encoding: utf-8 -*-
+# frozen_string_literal: false
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 
@@ -21,7 +22,7 @@ describe "String#chomp" do
 
     it "returns a copy of the String when it is not modified" do
       str = "abc"
-      str.chomp.should_not equal(str)
+      str.chomp.should_not.equal?(str)
     end
 
     it "removes one trailing newline" do
@@ -40,21 +41,23 @@ describe "String#chomp" do
       "".chomp.should == ""
     end
 
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc".taint.chomp.tainted?.should be_true
-      end
+    it "returns a String in the same encoding as self" do
+      "abc\n\n".encode("US-ASCII").chomp.encoding.should == Encoding::US_ASCII
     end
 
-    it "returns subclass instances when called on a subclass" do
+    it "returns String instances when called on a subclass" do
       str = StringSpecs::MyString.new("hello\n").chomp
-      str.should be_an_instance_of(StringSpecs::MyString)
+      str.should.instance_of?(String)
     end
 
     it "removes trailing characters that match $/ when it has been assigned a value" do
       $/ = "cdef"
       "abcdef".chomp.should == "ab"
     end
+
+    it "removes one trailing newline for string with invalid encoding" do
+      "\xa0\xa1\n".chomp.should == "\xa0\xa1"
+    end
   end
 
   describe "when passed nil" do
@@ -64,13 +67,7 @@ describe "String#chomp" do
 
     it "returns a copy of the String" do
       str = "abc"
-      str.chomp(nil).should_not equal(str)
-    end
-
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc".taint.chomp(nil).tainted?.should be_true
-      end
+      str.chomp(nil).should_not.equal?(str)
     end
 
     it "returns an empty String when self is empty" do
@@ -99,15 +96,13 @@ describe "String#chomp" do
       "abc\r\n\r\n\r\n".chomp("").should == "abc"
     end
 
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc".taint.chomp("").tainted?.should be_true
-      end
-    end
-
     it "returns an empty String when self is empty" do
       "".chomp("").should == ""
     end
+
+    it "removes one trailing newline for string with invalid encoding" do
+      "\xa0\xa1\n".chomp("").should == "\xa0\xa1"
+    end
   end
 
   describe "when passed '\\n'" do
@@ -123,12 +118,6 @@ describe "String#chomp" do
       "abc\r\n\r\n".chomp("\n").should == "abc\r\n"
     end
 
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc".taint.chomp("\n").tainted?.should be_true
-      end
-    end
-
     it "returns an empty String when self is empty" do
       "".chomp("\n").should == ""
     end
@@ -144,7 +133,7 @@ describe "String#chomp" do
     it "raises a TypeError if #to_str does not return a String" do
       arg = mock("string chomp")
       arg.should_receive(:to_str).and_return(1)
-      -> { "abc".chomp(arg) }.should raise_error(TypeError)
+      -> { "abc".chomp(arg) }.should.raise(TypeError)
     end
   end
 
@@ -161,16 +150,6 @@ describe "String#chomp" do
       "".chomp("abc").should == ""
     end
 
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc".taint.chomp("abc").tainted?.should be_true
-      end
-
-      it "does not taint the result when the argument is tainted" do
-        "abc".chomp("abc".taint).tainted?.should be_false
-      end
-    end
-
     it "returns an empty String when the argument equals self" do
       "abc".chomp("abc").should == ""
     end
@@ -192,11 +171,11 @@ describe "String#chomp!" do
 
     it "modifies self" do
       str = "abc\n"
-      str.chomp!.should equal(str)
+      str.chomp!.should.equal?(str)
     end
 
     it "returns nil if self is not modified" do
-      "abc".chomp!.should be_nil
+      "abc".chomp!.should == nil
     end
 
     it "removes one trailing newline" do
@@ -212,18 +191,12 @@ describe "String#chomp!" do
     end
 
     it "returns nil when self is empty" do
-      "".chomp!.should be_nil
-    end
-
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc\n".taint.chomp!.tainted?.should be_true
-      end
+      "".chomp!.should == nil
     end
 
     it "returns subclass instances when called on a subclass" do
       str = StringSpecs::MyString.new("hello\n").chomp!
-      str.should be_an_instance_of(StringSpecs::MyString)
+      str.should.instance_of?(StringSpecs::MyString)
     end
 
     it "removes trailing characters that match $/ when it has been assigned a value" do
@@ -234,11 +207,11 @@ describe "String#chomp!" do
 
   describe "when passed nil" do
     it "returns nil" do
-      "abc\r\n".chomp!(nil).should be_nil
+      "abc\r\n".chomp!(nil).should == nil
     end
 
     it "returns nil when self is empty" do
-      "".chomp!(nil).should be_nil
+      "".chomp!(nil).should == nil
     end
   end
 
@@ -252,7 +225,7 @@ describe "String#chomp!" do
     end
 
     it "does not remove a final carriage return" do
-      "abc\r".chomp!("").should be_nil
+      "abc\r".chomp!("").should == nil
     end
 
     it "removes more than one trailing newlines" do
@@ -263,14 +236,8 @@ describe "String#chomp!" do
       "abc\r\n\r\n\r\n".chomp!("").should == "abc"
     end
 
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc\n".taint.chomp!("").tainted?.should be_true
-      end
-    end
-
     it "returns nil when self is empty" do
-      "".chomp!("").should be_nil
+      "".chomp!("").should == nil
     end
   end
 
@@ -287,14 +254,8 @@ describe "String#chomp!" do
       "abc\r\n\r\n".chomp!("\n").should == "abc\r\n"
     end
 
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc\n".taint.chomp!("\n").tainted?.should be_true
-      end
-    end
-
     it "returns nil when self is empty" do
-      "".chomp!("\n").should be_nil
+      "".chomp!("\n").should == nil
     end
   end
 
@@ -308,7 +269,7 @@ describe "String#chomp!" do
     it "raises a TypeError if #to_str does not return a String" do
       arg = mock("string chomp")
       arg.should_receive(:to_str).and_return(1)
-      -> { "abc".chomp!(arg) }.should raise_error(TypeError)
+      -> { "abc".chomp!(arg) }.should.raise(TypeError)
     end
   end
 
@@ -318,21 +279,11 @@ describe "String#chomp!" do
     end
 
     it "returns nil if the argument does not match the trailing characters" do
-      "abc".chomp!("def").should be_nil
+      "abc".chomp!("def").should == nil
     end
 
     it "returns nil when self is empty" do
-      "".chomp!("abc").should be_nil
-    end
-
-    ruby_version_is ''...'2.7' do
-      it "taints the result if self is tainted" do
-        "abc".taint.chomp!("abc").tainted?.should be_true
-      end
-
-      it "does not taint the result when the argument is tainted" do
-        "abc".chomp!("abc".taint).tainted?.should be_false
-      end
+      "".chomp!("abc").should == nil
     end
   end
 
@@ -340,15 +291,15 @@ describe "String#chomp!" do
     a = "string\n\r"
     a.freeze
 
-    -> { a.chomp! }.should raise_error(FrozenError)
+    -> { a.chomp! }.should.raise(FrozenError)
   end
 
   # see [ruby-core:23666]
   it "raises a FrozenError on a frozen instance when it would not be modified" do
     a = "string\n\r"
     a.freeze
-    -> { a.chomp!(nil) }.should raise_error(FrozenError)
-    -> { a.chomp!("x") }.should raise_error(FrozenError)
+    -> { a.chomp!(nil) }.should.raise(FrozenError)
+    -> { a.chomp!("x") }.should.raise(FrozenError)
   end
 end
 
@@ -395,7 +346,7 @@ describe "String#chomp!" do
   end
 
   it "returns nil when the String is not modified" do
-    "あれ".chomp!.should be_nil
+    "あれ".chomp!.should == nil
   end
 
   it "removes the final carriage return, newline from a multibyte String" do