1 files changed, 11 insertions, 24 deletions
diff --git a/spec/ruby/core/string/shared/succ.rb b/spec/ruby/core/string/shared/succ.rb
index 25602103b6..8f1d327741 100644
--- a/spec/ruby/core/string/shared/succ.rb
+++ b/spec/ruby/core/string/shared/succ.rb
@@ -1,4 +1,4 @@
-# -*- encoding: binary -*-
+# encoding: binary
 describe :string_succ, shared: true do
   it "returns an empty string for empty strings" do
     "".send(@method).should == ""
@@ -59,42 +59,29 @@ describe :string_succ, shared: true do
     "\xFF\xFF".send(@method).should == "\x01\x00\x00"
   end
 
-  ruby_version_is ''...'3.0' do
-    it "returns subclass instances when called on a subclass" do
-      StringSpecs::MyString.new("").send(@method).should be_an_instance_of(StringSpecs::MyString)
-      StringSpecs::MyString.new("a").send(@method).should be_an_instance_of(StringSpecs::MyString)
-      StringSpecs::MyString.new("z").send(@method).should be_an_instance_of(StringSpecs::MyString)
-    end
+  it "returns String instances when called on a subclass" do
+    StringSpecs::MyString.new("").send(@method).should.instance_of?(String)
+    StringSpecs::MyString.new("a").send(@method).should.instance_of?(String)
+    StringSpecs::MyString.new("z").send(@method).should.instance_of?(String)
   end
 
-  ruby_version_is '3.0' do
-    it "returns String instances when called on a subclass" do
-      StringSpecs::MyString.new("").send(@method).should be_an_instance_of(String)
-      StringSpecs::MyString.new("a").send(@method).should be_an_instance_of(String)
-      StringSpecs::MyString.new("z").send(@method).should be_an_instance_of(String)
-    end
-  end
-
-  ruby_version_is ''...'2.7' do
-    it "taints the result if self is tainted" do
-      ["", "a", "z", "Z", "9", "\xFF", "\xFF\xFF"].each do |s|
-        s.taint.send(@method).should.tainted?
-      end
-    end
+  it "returns a String in the same encoding as self" do
+    "z".encode("US-ASCII").send(@method).encoding.should == Encoding::US_ASCII
   end
 end
 
 describe :string_succ_bang, shared: true do
   it "is equivalent to succ, but modifies self in place (still returns self)" do
     ["", "abcd", "THX1138"].each do |s|
+      s = +s
       r = s.dup.send(@method)
-      s.send(@method).should equal(s)
+      s.send(@method).should.equal?(s)
       s.should == r
     end
   end
 
   it "raises a FrozenError if self is frozen" do
-    -> { "".freeze.send(@method)     }.should raise_error(FrozenError)
-    -> { "abcd".freeze.send(@method) }.should raise_error(FrozenError)
+    -> { "".freeze.send(@method)     }.should.raise(FrozenError)
+    -> { "abcd".freeze.send(@method) }.should.raise(FrozenError)
   end
 end