Update to ruby/spec@4ce9f41

108 files changed, 1320 insertions, 265 deletions

diff --git a/spec/ruby/CONTRIBUTING.md b/spec/ruby/CONTRIBUTING.md
index 56e12736fc..e470a811ff 100644
--- a/spec/ruby/CONTRIBUTING.md
+++ b/spec/ruby/CONTRIBUTING.md
@@ -124,8 +124,8 @@ If an exception is raised, it will fail the example anyway.
 
 ```ruby
 -> {
-  Integer
-}.should complain(/constant ::Integer is deprecated/) # Expect a warning
+  Fixnum
+}.should complain(/constant ::Fixnum is deprecated/) # Expect a warning
 ```
 
 ### Guards
diff --git a/spec/ruby/README.md b/spec/ruby/README.md
index 932cd83061..8bdba2cb00 100644
--- a/spec/ruby/README.md
+++ b/spec/ruby/README.md
@@ -34,7 +34,8 @@ More precisely, every latest stable MRI release should [pass](https://travis-ci.
 
 ### Synchronization with Ruby Implementations
 
-The specs are synchronized both ways around once a month by @eregon between ruby/spec, MRI, JRuby and TruffleRuby.
+The specs are synchronized both ways around once a month by @eregon between ruby/spec, MRI, JRuby and TruffleRuby,
+using [this script](https://github.com/ruby/mspec/blob/master/tool/sync/sync-rubyspec.rb).
 Each of these repositories has a full copy of the specs under `spec/ruby` to ease editing specs.
 Any of these repositories can be used to add or edit specs, use what is most convenient for you.
 
diff --git a/spec/ruby/core/argf/bytes_spec.rb b/spec/ruby/core/argf/bytes_spec.rb
index 3e11a4f5c4..bf35ded1db 100644
--- a/spec/ruby/core/argf/bytes_spec.rb
+++ b/spec/ruby/core/argf/bytes_spec.rb
@@ -3,6 +3,14 @@ require_relative 'shared/each_byte'
 
 ruby_version_is ''...'3.0' do
   describe "ARGF.bytes" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :argf_each_byte, :bytes
   end
 end
diff --git a/spec/ruby/core/argf/chars_spec.rb b/spec/ruby/core/argf/chars_spec.rb
index a864ce6d52..6af73cdabb 100644
--- a/spec/ruby/core/argf/chars_spec.rb
+++ b/spec/ruby/core/argf/chars_spec.rb
@@ -3,6 +3,14 @@ require_relative 'shared/each_char'
 
 ruby_version_is ''...'3.0' do
   describe "ARGF.chars" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :argf_each_char, :chars
   end
 end
diff --git a/spec/ruby/core/argf/codepoints_spec.rb b/spec/ruby/core/argf/codepoints_spec.rb
index d3007c4c5b..bb28c17fbb 100644
--- a/spec/ruby/core/argf/codepoints_spec.rb
+++ b/spec/ruby/core/argf/codepoints_spec.rb
@@ -3,6 +3,14 @@ require_relative 'shared/each_codepoint'
 
 ruby_version_is ''...'3.0' do
   describe "ARGF.codepoints" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :argf_each_codepoint, :codepoints
   end
 end
diff --git a/spec/ruby/core/argf/lines_spec.rb b/spec/ruby/core/argf/lines_spec.rb
index 0bf5bb0d73..e964dbd0d3 100644
--- a/spec/ruby/core/argf/lines_spec.rb
+++ b/spec/ruby/core/argf/lines_spec.rb
@@ -3,6 +3,14 @@ require_relative 'shared/each_line'
 
 ruby_version_is ''...'3.0' do
   describe "ARGF.lines" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :argf_each_line, :lines
   end
 end
diff --git a/spec/ruby/core/array/element_set_spec.rb b/spec/ruby/core/array/element_set_spec.rb
index 2e01e838e9..1c143f3e37 100644
--- a/spec/ruby/core/array/element_set_spec.rb
+++ b/spec/ruby/core/array/element_set_spec.rb
@@ -439,7 +439,6 @@ end
 
 ruby_version_is "2.6" do
   describe "Array#[]= with [m..]" do
-
     it "just sets the section defined by range to nil even if the rhs is nil" do
       a = [1, 2, 3, 4, 5]
       a[eval("(2..)")] = nil
@@ -476,6 +475,53 @@ ruby_version_is "2.6" do
   end
 end
 
+ruby_version_is "2.7" do
+  describe "Array#[]= with [..n] and [...n]" do
+    it "just sets the section defined by range to nil even if the rhs is nil" do
+      a = [1, 2, 3, 4, 5]
+      a[eval("(..2)")] = nil
+      a.should == [nil, 4, 5]
+      a[eval("(...2)")] = nil
+      a.should == [nil, 5]
+    end
+
+    it "just sets the section defined by range to nil if n < 0 and the rhs is nil" do
+      a = [1, 2, 3, 4, 5]
+      a[eval("(..-3)")] = nil
+      a.should == [nil, 4, 5]
+      a[eval("(...-1)")] = [nil, 5]
+    end
+
+    it "replaces the section defined by range" do
+      a = [6, 5, 4, 3, 2, 1]
+      a[eval("(...3)")] = 9
+      a.should == [9, 3, 2, 1]
+      a[eval("(..2)")] = [7, 7, 7, 7, 7]
+      a.should == [7, 7, 7, 7, 7, 1]
+    end
+
+    it "replaces the section if n < 0" do
+      a = [1, 2, 3, 4, 5]
+      a[eval("(..-2)")] = [7, 8, 9]
+      a.should == [7, 8, 9, 5]
+    end
+
+    it "replaces everything if n > the array size" do
+      a = [1, 2, 3]
+      a[eval("(...7)")] = [4]
+      a.should == [4]
+    end
+
+    it "inserts at the beginning if n < negative the array size" do
+      a = [1, 2, 3]
+      a[eval("(..-7)")] = [4]
+      a.should == [4, 1, 2, 3]
+      a[eval("(...-10)")] = [6]
+      a.should == [6, 4, 1, 2, 3]
+    end
+  end
+end
+
 describe "Array#[] after a shift" do
   it "works for insertion" do
     a = [1,2]
diff --git a/spec/ruby/core/array/fill_spec.rb b/spec/ruby/core/array/fill_spec.rb
index 6745bc8d09..8f0814a5da 100644
--- a/spec/ruby/core/array/fill_spec.rb
+++ b/spec/ruby/core/array/fill_spec.rb
@@ -324,4 +324,11 @@ describe "Array#fill with (filler, range)" do
       [1, 2, 3, 4].fill(eval("(3...)")) { |x| x + 2 }.should == [1, 2, 3, 5]
     end
   end
+
+  ruby_version_is "2.7" do
+    it "works with beginless ranges" do
+      [1, 2, 3, 4].fill('x', eval("(..2)")).should == ["x", "x", "x", 4]
+      [1, 2, 3, 4].fill(eval("(...2)")) { |x| x + 2 }.should == [2, 3, 3, 4]
+    end
+  end
 end
diff --git a/spec/ruby/core/array/first_spec.rb b/spec/ruby/core/array/first_spec.rb
index 463da829a2..66eeba6565 100644
--- a/spec/ruby/core/array/first_spec.rb
+++ b/spec/ruby/core/array/first_spec.rb
@@ -33,7 +33,7 @@ describe "Array#first" do
     -> { [1, 2].first(-1) }.should raise_error(ArgumentError)
   end
 
-  it "raises a RangeError when count is an Integer" do
+  it "raises a RangeError when count is a Bignum" do
     -> { [].first(bignum_value) }.should raise_error(RangeError)
   end
 
diff --git a/spec/ruby/core/array/shared/slice.rb b/spec/ruby/core/array/shared/slice.rb
index 820047cdb2..6818badeda 100644
--- a/spec/ruby/core/array/shared/slice.rb
+++ b/spec/ruby/core/array/shared/slice.rb
@@ -486,7 +486,7 @@ describe :array_slice, shared: true do
     end
   end
 
-  it "raises a RangeError when the start index is out of range of Integer" do
+  it "raises a RangeError when the start index is out of range of Fixnum" do
     array = [1, 2, 3, 4, 5, 6]
     obj = mock('large value')
     obj.should_receive(:to_int).and_return(bignum_value)
@@ -502,7 +502,7 @@ describe :array_slice, shared: true do
     array.send(@method, max_long.to_f.prev_float).should == nil
   end
 
-  it "raises a RangeError when the length is out of range of Integer" do
+  it "raises a RangeError when the length is out of range of Fixnum" do
     array = [1, 2, 3, 4, 5, 6]
     obj = mock('large value')
     obj.should_receive(:to_int).and_return(bignum_value)
@@ -520,4 +520,41 @@ describe :array_slice, shared: true do
     -> { "hello".send(@method, bignum_value..(bignum_value + 1)) }.should raise_error(RangeError)
     -> { "hello".send(@method, 0..bignum_value) }.should raise_error(RangeError)
   end
+
+  ruby_version_is "2.6" do
+    it "can accept endless ranges" do
+      a = [0, 1, 2, 3, 4, 5]
+      a.send(@method, eval("(2..)")).should == [2, 3, 4, 5]
+      a.send(@method, eval("(2...)")).should == [2, 3, 4, 5]
+      a.send(@method, eval("(-2..)")).should == [4, 5]
+      a.send(@method, eval("(-2...)")).should == [4, 5]
+      a.send(@method, eval("(9..)")).should == nil
+      a.send(@method, eval("(9...)")).should == nil
+      a.send(@method, eval("(-9..)")).should == nil
+      a.send(@method, eval("(-9...)")).should == nil
+    end
+  end
+
+  ruby_version_is "2.7" do
+    it "can accept beginless ranges" do
+      a = [0, 1, 2, 3, 4, 5]
+      a.send(@method, eval("(..3)")).should == [0, 1, 2, 3]
+      a.send(@method, eval("(...3)")).should == [0, 1, 2]
+      a.send(@method, eval("(..-3)")).should == [0, 1, 2, 3]
+      a.send(@method, eval("(...-3)")).should == [0, 1, 2]
+      a.send(@method, eval("(..0)")).should == [0]
+      a.send(@method, eval("(...0)")).should == []
+      a.send(@method, eval("(..9)")).should == [0, 1, 2, 3, 4, 5]
+      a.send(@method, eval("(...9)")).should == [0, 1, 2, 3, 4, 5]
+      a.send(@method, eval("(..-9)")).should == []
+      a.send(@method, eval("(...-9)")).should == []
+    end
+
+    it "can accept nil...nil ranges" do
+      a = [0, 1, 2, 3, 4, 5]
+      a.send(@method, eval("(nil...nil)")).should == a
+      a.send(@method, eval("(...nil)")).should == a
+      a.send(@method, eval("(nil..)")).should == a
+    end
+  end
 end
diff --git a/spec/ruby/core/array/slice_spec.rb b/spec/ruby/core/array/slice_spec.rb
index 3829794938..f416d8d0ce 100644
--- a/spec/ruby/core/array/slice_spec.rb
+++ b/spec/ruby/core/array/slice_spec.rb
@@ -163,6 +163,26 @@ describe "Array#slice!" do
       a = [1, 2, 3]
       a.slice!(eval("(2...)")).should == [3]
       a.should == [1, 2]
+
+      a = [1, 2, 3]
+      a.slice!(eval("(-2..)")).should == [2, 3]
+      a.should == [1]
+
+      a = [1, 2, 3]
+      a.slice!(eval("(-1...)")).should == [3]
+      a.should == [1, 2]
+    end
+  end
+
+  ruby_version_is "2.7" do
+    it "works with beginless ranges" do
+      a = [0,1,2,3,4]
+      a.slice!(eval("(..3)")).should == [0, 1, 2, 3]
+      a.should == [4]
+
+      a = [0,1,2,3,4]
+      a.slice!(eval("(...-2)")).should == [0, 1, 2]
+      a.should == [3, 4]
     end
   end
 end
diff --git a/spec/ruby/core/array/values_at_spec.rb b/spec/ruby/core/array/values_at_spec.rb
index f6801335f8..019152c51c 100644
--- a/spec/ruby/core/array/values_at_spec.rb
+++ b/spec/ruby/core/array/values_at_spec.rb
@@ -67,4 +67,11 @@ describe "Array#values_at" do
       [1, 2, 3, 4].values_at(eval("(3...)")).should == [4]
     end
   end
+
+  ruby_version_is "2.7" do
+    it "works when given beginless ranges" do
+      [1, 2, 3, 4].values_at(eval("(..2)")).should == [1, 2, 3]
+      [1, 2, 3, 4].values_at(eval("(...2)")).should == [1, 2]
+    end
+  end
 end
diff --git a/spec/ruby/core/complex/coerce_spec.rb b/spec/ruby/core/complex/coerce_spec.rb
index 9023234e73..a30a6c1d5f 100644
--- a/spec/ruby/core/complex/coerce_spec.rb
+++ b/spec/ruby/core/complex/coerce_spec.rb
@@ -19,7 +19,7 @@ describe "Complex#coerce" do
     result.last.should be_kind_of(Complex)
   end
 
-  it "returns an array containing other and self as Complex when other is an Integer" do
+  it "returns an array containing other and self as Complex when other is a Bignum" do
     result = @one.coerce(4294967296)
     result.should == [4294967296, 1]
     result.first.should be_kind_of(Complex)
diff --git a/spec/ruby/core/complex/shared/divide.rb b/spec/ruby/core/complex/shared/divide.rb
index dc1b870cff..a60802c74c 100644
--- a/spec/ruby/core/complex/shared/divide.rb
+++ b/spec/ruby/core/complex/shared/divide.rb
@@ -12,7 +12,7 @@ describe :complex_divide, shared: true do
     end
   end
 
-  describe "with Integer" do
+  describe "with Fixnum" do
     it "divides both parts of the Complex number" do
       Complex(20, 40).send(@method, 2).should == Complex(10, 20)
       Complex(30, 30).send(@method, 10).should == Complex(3, 3)
@@ -27,7 +27,7 @@ describe :complex_divide, shared: true do
     end
   end
 
-  describe "with Integer" do
+  describe "with Bignum" do
     it "divides both parts of the Complex number" do
       Complex(20, 40).send(@method, 2).should == Complex(10, 20)
       Complex(15, 16).send(@method, 2.0).should be_close(Complex(7.5, 8), TOLERANCE)
diff --git a/spec/ruby/core/data/constants_spec.rb b/spec/ruby/core/data/constants_spec.rb
index a037bf6816..1d469f9237 100644
--- a/spec/ruby/core/data/constants_spec.rb
+++ b/spec/ruby/core/data/constants_spec.rb
@@ -13,3 +13,11 @@ ruby_version_is ''...'3.0' do
     end
   end
 end
+
+ruby_version_is '3.0' do
+  describe "Data" do
+    it "does not exist anymore" do
+      Object.should_not have_constant(:Data)
+    end
+  end
+end
diff --git a/spec/ruby/core/enumerable/first_spec.rb b/spec/ruby/core/enumerable/first_spec.rb
index 1398807fa7..ed1ba599b4 100644
--- a/spec/ruby/core/enumerable/first_spec.rb
+++ b/spec/ruby/core/enumerable/first_spec.rb
@@ -17,7 +17,7 @@ describe "Enumerable#first" do
     EnumerableSpecs::YieldsMixed2.new.to_enum.first.should == nil
   end
 
-  it "raises a RangeError when passed an Integer" do
+  it "raises a RangeError when passed a Bignum" do
     enum = EnumerableSpecs::Empty.new
     -> { enum.first(bignum_value) }.should raise_error(RangeError)
   end
diff --git a/spec/ruby/core/enumerable/shared/collect.rb b/spec/ruby/core/enumerable/shared/collect.rb
index 71b8acd526..32c1722c75 100644
--- a/spec/ruby/core/enumerable/shared/collect.rb
+++ b/spec/ruby/core/enumerable/shared/collect.rb
@@ -51,7 +51,20 @@ describe :enumerable_collect, shared: true do
     ScratchPad.recorded.should == [1]
   end
 
-  it "yields 2 arguments for a Hash" do
+  it "yields an Array of 2 elements for a Hash when block arity is 1" do
+    c = Class.new do
+      def register(a)
+        ScratchPad << a
+      end
+    end
+    m = c.new.method(:register)
+
+    ScratchPad.record []
+    { 1 => 'a', 2 => 'b' }.map(&m)
+    ScratchPad.recorded.should == [[1, 'a'], [2, 'b']]
+  end
+
+  it "yields 2 arguments for a Hash when block arity is 2" do
     c = Class.new do
       def register(a, b)
         ScratchPad << [a, b]
@@ -64,5 +77,17 @@ describe :enumerable_collect, shared: true do
     ScratchPad.recorded.should == [[1, 'a'], [2, 'b']]
   end
 
+  it "raises an error for a Hash when an arity enforcing block of arity >2 is passed in" do
+    c = Class.new do
+      def register(a, b, c)
+      end
+    end
+    m = c.new.method(:register)
+
+    -> do
+      { 1 => 'a', 2 => 'b' }.map(&m)
+    end.should raise_error(ArgumentError)
+  end
+
   it_should_behave_like :enumerable_enumeratorized_with_origin_size
 end
diff --git a/spec/ruby/core/enumerator/initialize_spec.rb b/spec/ruby/core/enumerator/initialize_spec.rb
index 113bbf9957..217af1d3bc 100644
--- a/spec/ruby/core/enumerator/initialize_spec.rb
+++ b/spec/ruby/core/enumerator/initialize_spec.rb
@@ -13,7 +13,9 @@ describe "Enumerator#initialize" do
 
   ruby_version_is ''...'3.0' do
     it "returns self when given an object" do
-      @uninitialized.send(:initialize, Object.new).should equal(@uninitialized)
+      suppress_warning do
+        @uninitialized.send(:initialize, Object.new).should equal(@uninitialized)
+      end
     end
   end
 
diff --git a/spec/ruby/core/enumerator/new_spec.rb b/spec/ruby/core/enumerator/new_spec.rb
index 9aea9fdd17..5cc0b3ff2e 100644
--- a/spec/ruby/core/enumerator/new_spec.rb
+++ b/spec/ruby/core/enumerator/new_spec.rb
@@ -10,25 +10,26 @@ describe "Enumerator.new" do
 
     ruby_version_is ''...'3.0' do
       it "creates a new custom enumerator with the given object, iterator and arguments" do
-        enum = Enumerator.new(1, :upto, 3)
+        enum = suppress_warning { Enumerator.new(1, :upto, 3) }
         enum.should be_an_instance_of(Enumerator)
       end
 
       it "creates a new custom enumerator that responds to #each" do
-        enum = Enumerator.new(1, :upto, 3)
+        enum = suppress_warning { Enumerator.new(1, :upto, 3) }
         enum.respond_to?(:each).should == true
       end
 
       it "creates a new custom enumerator that runs correctly" do
-        Enumerator.new(1, :upto, 3).map{|x|x}.should == [1,2,3]
+        suppress_warning { Enumerator.new(1, :upto, 3) }.map{ |x| x }.should == [1,2,3]
       end
 
       it "aliases the second argument to :each" do
-        Enumerator.new(1..2).to_a.should == Enumerator.new(1..2, :each).to_a
+        suppress_warning { Enumerator.new(1..2) }.to_a.should ==
+          suppress_warning { Enumerator.new(1..2, :each) }.to_a
       end
 
       it "doesn't check for the presence of the iterator method" do
-        Enumerator.new(nil).should be_an_instance_of(Enumerator)
+        suppress_warning { Enumerator.new(nil) }.should be_an_instance_of(Enumerator)
       end
 
       it "uses the latest define iterator method" do
@@ -37,7 +38,7 @@ describe "Enumerator.new" do
             yield :foo
           end
         end
-        enum = Enumerator.new(StrangeEach.new)
+        enum = suppress_warning { Enumerator.new(StrangeEach.new) }
         enum.to_a.should == [:foo]
         class StrangeEach
           def each
diff --git a/spec/ruby/core/env/element_reference_spec.rb b/spec/ruby/core/env/element_reference_spec.rb
index 22633e7a08..560c127a9c 100644
--- a/spec/ruby/core/env/element_reference_spec.rb
+++ b/spec/ruby/core/env/element_reference_spec.rb
@@ -1,5 +1,6 @@
 # -*- encoding: binary -*-
 require_relative '../../spec_helper'
+require_relative 'fixtures/common'
 
 describe "ENV.[]" do
   before :each do
@@ -58,8 +59,7 @@ describe "ENV.[]" do
   it "uses the locale encoding if Encoding.default_internal is nil" do
     Encoding.default_internal = nil
 
-    locale = Encoding.find('locale')
-    locale = Encoding::UTF_8 if platform_is :windows
+    locale = ENVSpecs.encoding
     locale = Encoding::BINARY if locale == Encoding::US_ASCII
     ENV[@variable] = "\xC3\xB8"
     ENV[@variable].encoding.should == locale
diff --git a/spec/ruby/core/env/fetch_spec.rb b/spec/ruby/core/env/fetch_spec.rb
index f3af6f3dc2..b2e7a88cab 100644
--- a/spec/ruby/core/env/fetch_spec.rb
+++ b/spec/ruby/core/env/fetch_spec.rb
@@ -1,5 +1,6 @@
 require_relative '../../spec_helper'
 require_relative '../../shared/hash/key_error'
+require_relative 'fixtures/common'
 
 describe "ENV.fetch" do
   before :each do
@@ -56,8 +57,7 @@ describe "ENV.fetch" do
   end
 
   it "uses the locale encoding" do
-    encoding = platform_is(:windows) ? Encoding::UTF_8 : Encoding.find('locale')
     ENV["foo"] = "bar"
-    ENV.fetch("foo").encoding.should == encoding
+    ENV.fetch("foo").encoding.should == ENVSpecs.encoding
   end
 end
diff --git a/spec/ruby/core/env/fixtures/common.rb b/spec/ruby/core/env/fixtures/common.rb
new file mode 100644
index 0000000000..8d5057614d
--- /dev/null
+++ b/spec/ruby/core/env/fixtures/common.rb
@@ -0,0 +1,9 @@
+module ENVSpecs
+  def self.encoding
+    locale = Encoding.find('locale')
+    if ruby_version_is '3' and platform_is :windows
+      locale = Encoding::UTF_8
+    end
+    locale
+  end
+end
diff --git a/spec/ruby/core/env/shift_spec.rb b/spec/ruby/core/env/shift_spec.rb
index 49d98c3729..b6c139dc29 100644
--- a/spec/ruby/core/env/shift_spec.rb
+++ b/spec/ruby/core/env/shift_spec.rb
@@ -1,4 +1,5 @@
 require_relative '../../spec_helper'
+require_relative 'fixtures/common'
 
 describe "ENV.shift" do
   it "returns a pair and deletes it" do
@@ -42,10 +43,9 @@ describe "ENV.shift" do
   it "uses the locale encoding if Encoding.default_internal is nil" do
     Encoding.default_internal = nil
 
-    encoding = platform_is(:windows) ? Encoding::UTF_8 : Encoding.find('locale')
     pair = ENV.shift
-    pair.first.encoding.should equal(encoding)
-    pair.last.encoding.should equal(encoding)
+    pair.first.encoding.should equal(ENVSpecs.encoding)
+    pair.last.encoding.should equal(ENVSpecs.encoding)
   end
 
   it "transcodes from the locale encoding to Encoding.default_internal if set" do
diff --git a/spec/ruby/core/env/values_at_spec.rb b/spec/ruby/core/env/values_at_spec.rb
index 87c8c7f663..338680e820 100644
--- a/spec/ruby/core/env/values_at_spec.rb
+++ b/spec/ruby/core/env/values_at_spec.rb
@@ -1,4 +1,5 @@
 require_relative '../../spec_helper'
+require_relative 'fixtures/common'
 
 describe "ENV.values_at" do
   before :each do
@@ -28,8 +29,7 @@ describe "ENV.values_at" do
   end
 
   it "uses the locale encoding" do
-    encoding = platform_is(:windows) ? Encoding::UTF_8 : Encoding.find('locale')
-    ENV.values_at(ENV.keys.first).first.encoding.should == encoding
+    ENV.values_at(ENV.keys.first).first.encoding.should == ENVSpecs.encoding
   end
 
   it "raises TypeError when a key is not coercible to String" do
diff --git a/spec/ruby/core/hash/shared/each.rb b/spec/ruby/core/hash/shared/each.rb
index 04a26b5c45..b2483c8116 100644
--- a/spec/ruby/core/hash/shared/each.rb
+++ b/spec/ruby/core/hash/shared/each.rb
@@ -54,6 +54,27 @@ describe :hash_each, shared: true do
     end
   end
 
+  it "yields an Array of 2 elements when given a callable of arity 1" do
+    obj = Object.new
+    def obj.foo(key_value)
+      ScratchPad << key_value
+    end
+
+    ScratchPad.record([])
+    { "a" => 1 }.send(@method, &obj.method(:foo))
+    ScratchPad.recorded.should == [["a", 1]]
+  end
+
+  it "raises an error for a Hash when an arity enforcing callable of arity >2 is passed in" do
+    obj = Object.new
+    def obj.foo(key, value, extra)
+    end
+
+    -> {
+      { "a" => 1 }.send(@method, &obj.method(:foo))
+    }.should raise_error(ArgumentError)
+  end
+
   it "uses the same order as keys() and values()" do
     h = { a: 1, b: 2, c: 3, d: 5 }
     keys = []
diff --git a/spec/ruby/core/hash/shared/index.rb b/spec/ruby/core/hash/shared/index.rb
index 4858ba85f5..7f6a186464 100644
--- a/spec/ruby/core/hash/shared/index.rb
+++ b/spec/ruby/core/hash/shared/index.rb
@@ -3,25 +3,35 @@ require_relative '../fixtures/classes'
 
 describe :hash_index, shared: true do
   it "returns the corresponding key for value" do
-    { 2 => 'a', 1 => 'b' }.send(@method, 'b').should == 1
+    suppress_warning do # for Hash#index
+      { 2 => 'a', 1 => 'b' }.send(@method, 'b').should == 1
+    end
   end
 
   it "returns nil if the value is not found" do
-    { a: -1, b: 3.14, c: 2.718 }.send(@method, 1).should be_nil
+    suppress_warning do # for Hash#index
+      { a: -1, b: 3.14, c: 2.718 }.send(@method, 1).should be_nil
+    end
   end
 
   it "doesn't return default value if the value is not found" do
-    Hash.new(5).send(@method, 5).should be_nil
+    suppress_warning do # for Hash#index
+      Hash.new(5).send(@method, 5).should be_nil
+    end
   end
 
   it "compares values using ==" do
-    { 1 => 0 }.send(@method, 0.0).should == 1
-    { 1 => 0.0 }.send(@method, 0).should == 1
+    suppress_warning do # for Hash#index
+      { 1 => 0 }.send(@method, 0.0).should == 1
+      { 1 => 0.0 }.send(@method, 0).should == 1
+    end
 
     needle = mock('needle')
     inhash = mock('inhash')
     inhash.should_receive(:==).with(needle).and_return(true)
 
-    { 1 => inhash }.send(@method, needle).should == 1
+    suppress_warning do # for Hash#index
+      { 1 => inhash }.send(@method, needle).should == 1
+    end
   end
 end
diff --git a/spec/ruby/core/integer/coerce_spec.rb b/spec/ruby/core/integer/coerce_spec.rb
index 4d540bfb87..f1f3256032 100644
--- a/spec/ruby/core/integer/coerce_spec.rb
+++ b/spec/ruby/core/integer/coerce_spec.rb
@@ -4,8 +4,8 @@ require 'bigdecimal'
 
 describe "Integer#coerce" do
   context "fixnum" do
-    describe "when given an Integer" do
-      it "returns an array containing two Integers" do
+    describe "when given a Fixnum" do
+      it "returns an array containing two Fixnums" do
         1.coerce(2).should == [2, 1]
         1.coerce(2).map { |i| i.class }.should == [Integer, Integer]
       end
@@ -42,7 +42,7 @@ describe "Integer#coerce" do
   end
 
   context "bignum" do
-    it "coerces other to an Integer and returns [other, self] when passed an Integer" do
+    it "coerces other to a Bignum and returns [other, self] when passed a Fixnum" do
       a = bignum_value
       ary = a.coerce(2)
 
@@ -51,7 +51,7 @@ describe "Integer#coerce" do
       ary.should == [2, a]
     end
 
-    it "returns [other, self] when passed an Integer" do
+    it "returns [other, self] when passed a Bignum" do
       a = bignum_value
       b = bignum_value
       ary = a.coerce(b)
@@ -61,7 +61,7 @@ describe "Integer#coerce" do
       ary.should == [b, a]
     end
 
-    it "raises a TypeError when not passed an Integer" do
+    it "raises a TypeError when not passed a Fixnum or Bignum" do
       a = bignum_value
 
       -> { a.coerce(nil)         }.should raise_error(TypeError)
diff --git a/spec/ruby/core/integer/comparison_spec.rb b/spec/ruby/core/integer/comparison_spec.rb
index a0d8d24119..408c8e52ce 100644
--- a/spec/ruby/core/integer/comparison_spec.rb
+++ b/spec/ruby/core/integer/comparison_spec.rb
@@ -27,7 +27,7 @@ describe "Integer#<=>" do
   end
 
   context "bignum" do
-    describe "with an Integer" do
+    describe "with a Fixnum" do
       it "returns -1 when other is larger" do
         (-bignum_value <=> 2).should == -1
       end
@@ -37,7 +37,7 @@ describe "Integer#<=>" do
       end
     end
 
-    describe "with an Integer" do
+    describe "with a Bignum" do
       describe "when other is negative" do
         it "returns -1 when self is negative and other is larger" do
           (-bignum_value(42) <=> -bignum_value).should == -1
@@ -158,7 +158,7 @@ describe "Integer#<=>" do
     end
 
     # The tests below are taken from matz's revision 23730 for Ruby trunk
-    it "returns 1 when self is Infinity and other is an Integer" do
+    it "returns 1 when self is Infinity and other is a Bignum" do
       (infinity_value <=> Float::MAX.to_i*2).should == 1
     end
 
diff --git a/spec/ruby/core/integer/constants_spec.rb b/spec/ruby/core/integer/constants_spec.rb
index 35601f82b9..3b8b01e330 100644
--- a/spec/ruby/core/integer/constants_spec.rb
+++ b/spec/ruby/core/integer/constants_spec.rb
@@ -1,27 +1,25 @@
 require_relative '../../spec_helper'
 
-ruby_version_is ""..."3.0" do
-  describe "Fixnum" do
-    it "is unified into Integer" do
-      suppress_warning do
-        Fixnum.should equal(Integer)
-      end
+describe "Fixnum" do
+  it "is unified into Integer" do
+    suppress_warning do
+      Fixnum.should equal(Integer)
     end
+  end
 
-    it "is deprecated" do
-      -> { Fixnum }.should complain(/constant ::Fixnum is deprecated/)
-    end
+  it "is deprecated" do
+    -> { Fixnum }.should complain(/constant ::Fixnum is deprecated/)
   end
+end
 
-  describe "Bignum" do
-    it "is unified into Integer" do
-      suppress_warning do
-        Bignum.should equal(Integer)
-      end
+describe "Bignum" do
+  it "is unified into Integer" do
+    suppress_warning do
+      Bignum.should equal(Integer)
     end
+  end
 
-    it "is deprecated" do
-      -> { Bignum }.should complain(/constant ::Bignum is deprecated/)
-    end
+  it "is deprecated" do
+    -> { Bignum }.should complain(/constant ::Bignum is deprecated/)
   end
 end
diff --git a/spec/ruby/core/integer/denominator_spec.rb b/spec/ruby/core/integer/denominator_spec.rb
index d19b8175a3..c1477d0757 100644
--- a/spec/ruby/core/integer/denominator_spec.rb
+++ b/spec/ruby/core/integer/denominator_spec.rb
@@ -7,7 +7,7 @@ describe "Integer#denominator" do
     @numbers = [
       20,             # Integer
       -2709,          # Negative Integer
-      99999999**99,   # Integer
+      99999999**99,   # Bignum
       -99999**621,    # Negative BigNum
       0,
       1
diff --git a/spec/ruby/core/integer/element_reference_spec.rb b/spec/ruby/core/integer/element_reference_spec.rb
index 6e65c50254..7197ecdc03 100644
--- a/spec/ruby/core/integer/element_reference_spec.rb
+++ b/spec/ruby/core/integer/element_reference_spec.rb
@@ -68,14 +68,14 @@ describe "Integer#[]" do
       -> { 3[obj] }.should raise_error(TypeError)
     end
 
-    it "calls #to_int to coerce a String to an Integer and returns 0" do
+    it "calls #to_int to coerce a String to a Bignum and returns 0" do
       obj = mock('bignum value')
       obj.should_receive(:to_int).and_return(bignum_value)
 
       3[obj].should == 0
     end
 
-    it "returns 0 when passed a Float in the range of an Integer" do
+    it "returns 0 when passed a Float in the range of a Bignum" do
       3[bignum_value.to_f].should == 0
     end
 
@@ -131,16 +131,10 @@ describe "Integer#[]" do
           0b000001[-3, 4].should == 0b1000
         end
 
-        it "ignores negative upper boundary" do
-          0b101001101[1..-1].should == 0b10100110
-          0b101001101[1..-2].should == 0b10100110
-          0b101001101[1..-3].should == 0b10100110
-        end
-
         it "ignores upper boundary smaller than lower boundary" do
           0b101001101[4..1].should == 0b10100
           0b101001101[4..2].should == 0b10100
-          0b101001101[4..3].should == 0b10100
+          0b101001101[-4..-5].should == 0b1010011010000
         end
 
         it "raises FloatDomainError if any boundary is infinity" do
diff --git a/spec/ruby/core/integer/even_spec.rb b/spec/ruby/core/integer/even_spec.rb
index a93f54c74e..a314cc6b19 100644
--- a/spec/ruby/core/integer/even_spec.rb
+++ b/spec/ruby/core/integer/even_spec.rb
@@ -2,7 +2,7 @@ require_relative '../../spec_helper'
 
 describe "Integer#even?" do
   context "fixnum" do
-    it "returns true for an Integer when it is an even number" do
+    it "returns true for a Fixnum when it is an even number" do
       (-2).even?.should be_true
       (-1).even?.should be_false
 
@@ -11,7 +11,7 @@ describe "Integer#even?" do
       2.even?.should be_true
     end
 
-    it "returns true for an Integer when it is an even number" do
+    it "returns true for a Bignum when it is an even number" do
       bignum_value(0).even?.should be_true
       bignum_value(1).even?.should be_false
 
diff --git a/spec/ruby/core/integer/gcd_spec.rb b/spec/ruby/core/integer/gcd_spec.rb
index 82086d742a..961f1c5c2e 100644
--- a/spec/ruby/core/integer/gcd_spec.rb
+++ b/spec/ruby/core/integer/gcd_spec.rb
@@ -31,13 +31,13 @@ describe "Integer#gcd" do
     -100.gcd(-100).should == 100
   end
 
-  it "accepts an Integer argument" do
+  it "accepts a Bignum argument" do
     bignum = 9999**99
     bignum.should be_kind_of(Integer)
     99.gcd(bignum).should == 99
   end
 
-  it "works if self is an Integer" do
+  it "works if self is a Bignum" do
     bignum = 9999**99
     bignum.should be_kind_of(Integer)
     bignum.gcd(99).should == 99
diff --git a/spec/ruby/core/integer/gcdlcm_spec.rb b/spec/ruby/core/integer/gcdlcm_spec.rb
index 2915750f88..ebf45e55a1 100644
--- a/spec/ruby/core/integer/gcdlcm_spec.rb
+++ b/spec/ruby/core/integer/gcdlcm_spec.rb
@@ -26,13 +26,13 @@ describe "Integer#gcdlcm" do
     200.gcdlcm(20)[1].should == 200.lcm(20)
   end
 
-  it "accepts an Integer argument" do
+  it "accepts a Bignum argument" do
     bignum = 91999**99
     bignum.should be_kind_of(Integer)
     99.gcdlcm(bignum).should == [99.gcd(bignum), 99.lcm(bignum)]
   end
 
-  it "works if self is an Integer" do
+  it "works if self is a Bignum" do
     bignum = 9999**89
     bignum.should be_kind_of(Integer)
     bignum.gcdlcm(99).should == [bignum.gcd(99), bignum.lcm(99)]
diff --git a/spec/ruby/core/integer/lcm_spec.rb b/spec/ruby/core/integer/lcm_spec.rb
index 39976ea474..296a001c8c 100644
--- a/spec/ruby/core/integer/lcm_spec.rb
+++ b/spec/ruby/core/integer/lcm_spec.rb
@@ -31,13 +31,13 @@ describe "Integer#lcm" do
     -100.lcm(-100).should == 100
   end
 
-  it "accepts an Integer argument" do
+  it "accepts a Bignum argument" do
     bignum = 9999**99
     bignum.should be_kind_of(Integer)
     99.lcm(bignum).should == bignum
   end
 
-  it "works if self is an Integer" do
+  it "works if self is a Bignum" do
     bignum = 9999**99
     bignum.should be_kind_of(Integer)
     bignum.lcm(99).should == bignum
diff --git a/spec/ruby/core/integer/left_shift_spec.rb b/spec/ruby/core/integer/left_shift_spec.rb
index d2ffe4bbeb..4efcbef334 100644
--- a/spec/ruby/core/integer/left_shift_spec.rb
+++ b/spec/ruby/core/integer/left_shift_spec.rb
@@ -52,17 +52,17 @@ describe "Integer#<< (with n << m)" do
       (-7 << -64).should == -1
     end
 
-    it "returns 0 when m < 0 and m is an Integer" do
+    it "returns 0 when m < 0 and m is a Bignum" do
       (3 << -bignum_value).should == 0
     end
 
-    it "returns an Integer == fixnum_max * 2 when fixnum_max << 1 and n > 0" do
+    it "returns an Bignum == fixnum_max * 2 when fixnum_max << 1 and n > 0" do
       result = fixnum_max << 1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_max * 2
     end
 
-    it "returns an Integer == fixnum_min * 2 when fixnum_min << 1 and n < 0" do
+    it "returns an Bignum == fixnum_min * 2 when fixnum_min << 1 and n < 0" do
       result = fixnum_min << 1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_min * 2
@@ -127,17 +127,17 @@ describe "Integer#<< (with n << m)" do
       (@bignum << -68).should == 0
     end
 
-    it "returns 0 when m < 0 and m is an Integer" do
+    it "returns 0 when m < 0 and m is a Bignum" do
       (@bignum << -bignum_value).should == 0
     end
 
-    it "returns an Integer == fixnum_max when (fixnum_max * 2) << -1 and n > 0" do
+    it "returns a Fixnum == fixnum_max when (fixnum_max * 2) << -1 and n > 0" do
       result = (fixnum_max * 2) << -1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_max
     end
 
-    it "returns an Integer == fixnum_min when (fixnum_min * 2) << -1 and n < 0" do
+    it "returns a Fixnum == fixnum_min when (fixnum_min * 2) << -1 and n < 0" do
       result = (fixnum_min * 2) << -1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_min
diff --git a/spec/ruby/core/integer/right_shift_spec.rb b/spec/ruby/core/integer/right_shift_spec.rb
index 62cbe862b9..6abcd8d714 100644
--- a/spec/ruby/core/integer/right_shift_spec.rb
+++ b/spec/ruby/core/integer/right_shift_spec.rb
@@ -56,13 +56,13 @@ describe "Integer#>> (with n >> m)" do
       (3 >> bignum_value).should == 0
     end
 
-    it "returns an Integer == fixnum_max * 2 when fixnum_max >> -1 and n > 0" do
+    it "returns an Bignum == fixnum_max * 2 when fixnum_max >> -1 and n > 0" do
       result = fixnum_max >> -1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_max * 2
     end
 
-    it "returns an Integer == fixnum_min * 2 when fixnum_min >> -1 and n < 0" do
+    it "returns an Bignum == fixnum_min * 2 when fixnum_min >> -1 and n < 0" do
       result = fixnum_min >> -1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_min * 2
@@ -153,17 +153,17 @@ describe "Integer#>> (with n >> m)" do
       (@bignum >> 68).should == 0
     end
 
-    it "returns 0 when m is an Integer" do
+    it "returns 0 when m is a Bignum" do
       (@bignum >> bignum_value).should == 0
     end
 
-    it "returns an Integer == fixnum_max when (fixnum_max * 2) >> 1 and n > 0" do
+    it "returns a Fixnum == fixnum_max when (fixnum_max * 2) >> 1 and n > 0" do
       result = (fixnum_max * 2) >> 1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_max
     end
 
-    it "returns an Integer == fixnum_min when (fixnum_min * 2) >> 1 and n < 0" do
+    it "returns a Fixnum == fixnum_min when (fixnum_min * 2) >> 1 and n < 0" do
       result = (fixnum_min * 2) >> 1
       result.should be_an_instance_of(Integer)
       result.should == fixnum_min
diff --git a/spec/ruby/core/integer/shared/exponent.rb b/spec/ruby/core/integer/shared/exponent.rb
index f292cc2448..f949c514c8 100644
--- a/spec/ruby/core/integer/shared/exponent.rb
+++ b/spec/ruby/core/integer/shared/exponent.rb
@@ -47,7 +47,9 @@ describe :integer_exponent, shared: true do
     end
 
     it "returns Float::INFINITY when the number is too big" do
-      2.send(@method, 427387904).should == Float::INFINITY
+      -> {
+        2.send(@method, 427387904).should == Float::INFINITY
+      }.should complain(/warning: in a\*\*b, b may be too big/)
     end
 
     it "raises a ZeroDivisionError for 0 ** -1" do
@@ -105,7 +107,10 @@ describe :integer_exponent, shared: true do
     end
 
     it "switch to a Float when the values is too big" do
-      flt = @bignum.send(@method, @bignum)
+      flt = nil
+      -> {
+        flt = @bignum.send(@method, @bignum)
+      }.should complain(/warning: in a\*\*b, b may be too big/)
       flt.should be_kind_of(Float)
       flt.infinite?.should == 1
     end
diff --git a/spec/ruby/core/integer/shared/next.rb b/spec/ruby/core/integer/shared/next.rb
index fd983d53ec..85b83d6965 100644
--- a/spec/ruby/core/integer/shared/next.rb
+++ b/spec/ruby/core/integer/shared/next.rb
@@ -1,25 +1,25 @@
 describe :integer_next, shared: true do
-  it "returns the next larger positive Integer" do
+  it "returns the next larger positive Fixnum" do
     2.send(@method).should == 3
   end
 
-  it "returns the next larger negative Integer" do
+  it "returns the next larger negative Fixnum" do
     (-2).send(@method).should == -1
   end
 
-  it "returns the next larger positive Integer" do
+  it "returns the next larger positive Bignum" do
     bignum_value.send(@method).should == bignum_value(1)
   end
 
-  it "returns the next larger negative Integer" do
+  it "returns the next larger negative Bignum" do
     (-bignum_value(1)).send(@method).should == -bignum_value
   end
 
-  it "overflows an Integer to an Integer" do
+  it "overflows a Fixnum to a Bignum" do
     fixnum_max.send(@method).should == fixnum_max + 1
   end
 
-  it "underflows an Integer to an Integer" do
+  it "underflows a Bignum to a Fixnum" do
     (fixnum_min - 1).send(@method).should == fixnum_min
   end
 end
diff --git a/spec/ruby/core/integer/to_r_spec.rb b/spec/ruby/core/integer/to_r_spec.rb
index ac998e2a30..7732bedca1 100644
--- a/spec/ruby/core/integer/to_r_spec.rb
+++ b/spec/ruby/core/integer/to_r_spec.rb
@@ -13,7 +13,7 @@ describe "Integer#to_r" do
     298.to_r.denominator.should == 1
   end
 
-  it "works even if self is an Integer" do
+  it "works even if self is a Bignum" do
     bignum = 99999**999
     bignum.should be_an_instance_of(Integer)
     bignum.to_r.should == Rational(bignum, 1)
diff --git a/spec/ruby/core/integer/uminus_spec.rb b/spec/ruby/core/integer/uminus_spec.rb
index efaed1d2a6..b6b110dec4 100644
--- a/spec/ruby/core/integer/uminus_spec.rb
+++ b/spec/ruby/core/integer/uminus_spec.rb
@@ -10,7 +10,7 @@ describe "Integer#-@" do
       -8.send(:-@).should == 8
     end
 
-    it "negates self at Integer/Integer boundaries" do
+    it "negates self at Fixnum/Bignum boundaries" do
       (-fixnum_max).should == (0 - fixnum_max)
       (-fixnum_max).should < 0
       (-fixnum_min).should == (0 - fixnum_min)
diff --git a/spec/ruby/core/io/bytes_spec.rb b/spec/ruby/core/io/bytes_spec.rb
index 27a44a7c6c..6e328983f2 100644
--- a/spec/ruby/core/io/bytes_spec.rb
+++ b/spec/ruby/core/io/bytes_spec.rb
@@ -6,9 +6,11 @@ ruby_version_is ''...'3.0' do
   describe "IO#bytes" do
     before :each do
       @io = IOSpecs.io_fixture "lines.txt"
+      @verbose, $VERBOSE = $VERBOSE, nil
     end
 
     after :each do
+      $VERBOSE = @verbose
       @io.close unless @io.closed?
     end
 
diff --git a/spec/ruby/core/io/chars_spec.rb b/spec/ruby/core/io/chars_spec.rb
index 812ddbf34f..15db595aed 100644
--- a/spec/ruby/core/io/chars_spec.rb
+++ b/spec/ruby/core/io/chars_spec.rb
@@ -5,10 +5,26 @@ require_relative 'shared/chars'
 
 ruby_version_is ''...'3.0' do
   describe "IO#chars" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :io_chars, :chars
   end
 
   describe "IO#chars" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :io_chars_empty, :chars
   end
 end
diff --git a/spec/ruby/core/io/codepoints_spec.rb b/spec/ruby/core/io/codepoints_spec.rb
index 6b275af8d1..04c115dd3f 100644
--- a/spec/ruby/core/io/codepoints_spec.rb
+++ b/spec/ruby/core/io/codepoints_spec.rb
@@ -6,15 +6,25 @@ ruby_version_is ''...'3.0' do
 
   # See redmine #1667
   describe "IO#codepoints" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :io_codepoints, :codepoints
   end
 
   describe "IO#codepoints" do
     before :each do
       @io = IOSpecs.io_fixture "lines.txt"
+      @verbose, $VERBOSE = $VERBOSE, nil
     end
 
     after :each do
+      $VERBOSE = @verbose
       @io.close unless @io.closed?
     end
 
diff --git a/spec/ruby/core/io/lines_spec.rb b/spec/ruby/core/io/lines_spec.rb
index 947c068f42..5b29a1d07e 100644
--- a/spec/ruby/core/io/lines_spec.rb
+++ b/spec/ruby/core/io/lines_spec.rb
@@ -6,9 +6,11 @@ ruby_version_is ''...'3.0' do
   describe "IO#lines" do
     before :each do
       @io = IOSpecs.io_fixture "lines.txt"
+      @verbose, $VERBOSE = $VERBOSE, nil
     end
 
     after :each do
+      $VERBOSE = @verbose
       @io.close if @io
     end
 
diff --git a/spec/ruby/core/io/write_spec.rb b/spec/ruby/core/io/write_spec.rb
index 9c9b8b254b..60e66e998f 100644
--- a/spec/ruby/core/io/write_spec.rb
+++ b/spec/ruby/core/io/write_spec.rb
@@ -90,6 +90,12 @@ describe "IO.write" do
     IO.write(@filename, 'hi', mode: "w", encoding: Encoding::UTF_32LE).should == 8
   end
 
+  it "writes the file with the permissions in the :perm parameter" do
+    rm_r @filename
+    IO.write(@filename, 'write :perm spec', mode: "w", perm: 0o755).should == 16
+    (File.stat(@filename).mode & 0o777) == 0o755
+  end
+
   it "writes binary data if no encoding is given" do
     IO.write(@filename, 'Hëllö'.encode('ISO-8859-1'))
     xEB = [235].pack('C*')
diff --git a/spec/ruby/core/kernel/Float_spec.rb b/spec/ruby/core/kernel/Float_spec.rb
index ce224cada9..af64fcbe86 100644
--- a/spec/ruby/core/kernel/Float_spec.rb
+++ b/spec/ruby/core/kernel/Float_spec.rb
@@ -9,7 +9,7 @@ describe :kernel_float, shared: true do
     float2.should equal float
   end
 
-  it "returns a Float for Integers" do
+  it "returns a Float for Fixnums" do
     @object.send(:Float, 1).should == 1.0
   end
 
@@ -17,7 +17,7 @@ describe :kernel_float, shared: true do
     @object.send(:Float, Complex(1)).should == 1.0
   end
 
-  it "returns a Float for Integers" do
+  it "returns a Float for Bignums" do
     @object.send(:Float, 1000000000000).should == 1000000000000.0
   end
 
diff --git a/spec/ruby/core/kernel/Integer_spec.rb b/spec/ruby/core/kernel/Integer_spec.rb
index 674c7dd185..74bea7ca09 100644
--- a/spec/ruby/core/kernel/Integer_spec.rb
+++ b/spec/ruby/core/kernel/Integer_spec.rb
@@ -2,11 +2,11 @@ require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 
 describe :kernel_integer, shared: true do
-  it "returns an Integer for an Integer" do
+  it "returns a Bignum for a Bignum" do
     Integer(2e100).should == 2e100
   end
 
-  it "returns an Integer for an Integer" do
+  it "returns a Fixnum for a Fixnum" do
     Integer(100).should == 100
   end
 
@@ -39,7 +39,7 @@ describe :kernel_integer, shared: true do
     -> { Integer(nil) }.should raise_error(TypeError)
   end
 
-  it "returns an Integer or Integer object" do
+  it "returns an Integer object" do
     Integer(2).should be_an_instance_of(Integer)
     Integer(9**99).should be_an_instance_of(Integer)
   end
@@ -54,14 +54,14 @@ describe :kernel_integer, shared: true do
     Integer(3.quo(2)).should == 1
   end
 
-  it "returns the value of to_int if the result is an Integer" do
+  it "returns the value of to_int if the result is a Fixnum" do
     obj = mock("object")
     obj.should_receive(:to_int).and_return(1)
     obj.should_not_receive(:to_i)
     Integer(obj).should == 1
   end
 
-  it "returns the value of to_int if the result is an Integer" do
+  it "returns the value of to_int if the result is a Bignum" do
     obj = mock("object")
     obj.should_receive(:to_int).and_return(2 * 10**100)
     obj.should_not_receive(:to_i)
diff --git a/spec/ruby/core/marshal/dump_spec.rb b/spec/ruby/core/marshal/dump_spec.rb
index 0e50df7227..8d6ba245af 100644
--- a/spec/ruby/core/marshal/dump_spec.rb
+++ b/spec/ruby/core/marshal/dump_spec.rb
@@ -15,8 +15,8 @@ describe "Marshal.dump" do
     Marshal.dump(false).should == "\004\bF"
   end
 
-  describe "with an Integer" do
-    it "dumps an Integer" do
+  describe "with a Fixnum" do
+    it "dumps a Fixnum" do
       [ [Marshal,  0,       "\004\bi\000"],
         [Marshal,  5,       "\004\bi\n"],
         [Marshal,  8,       "\004\bi\r"],
@@ -38,11 +38,11 @@ describe "Marshal.dump" do
     end
 
     platform_is wordsize: 64 do
-      it "dumps a positive Integer > 31 bits as an Integer" do
+      it "dumps a positive Fixnum > 31 bits as a Bignum" do
         Marshal.dump(2**31 + 1).should == "\x04\bl+\a\x01\x00\x00\x80"
       end
 
-      it "dumps a negative Integer > 31 bits as an Integer" do
+      it "dumps a negative Fixnum > 31 bits as a Bignum" do
         Marshal.dump(-2**31 - 1).should == "\x04\bl-\a\x01\x00\x00\x80"
       end
     end
@@ -157,14 +157,14 @@ describe "Marshal.dump" do
     end
   end
 
-  describe "with an Integer" do
-    it "dumps an Integer" do
+  describe "with a Bignum" do
+    it "dumps a Bignum" do
       [ [Marshal, -4611686018427387903,    "\004\bl-\t\377\377\377\377\377\377\377?"],
         [Marshal, -2361183241434822606847, "\004\bl-\n\377\377\377\377\377\377\377\377\177\000"],
       ].should be_computed_by(:dump)
     end
 
-    it "dumps an Integer" do
+    it "dumps a Bignum" do
       [ [Marshal,  2**64, "\004\bl+\n\000\000\000\000\000\000\000\000\001\000"],
         [Marshal,  2**90, "\004\bl+\v#{"\000" * 11}\004"],
         [Marshal, -2**63, "\004\bl-\t\000\000\000\000\000\000\000\200"],
diff --git a/spec/ruby/core/marshal/shared/load.rb b/spec/ruby/core/marshal/shared/load.rb
index 9d42b9df4a..4e940c80a8 100644
--- a/spec/ruby/core/marshal/shared/load.rb
+++ b/spec/ruby/core/marshal/shared/load.rb
@@ -211,14 +211,14 @@ describe :marshal_load, shared: true do
         y.first.tainted?.should be_false
       end
 
-      it "does not taint Integers" do
+      it "does not taint Fixnums" do
         x = [1]
         y = Marshal.send(@method, Marshal.dump(x).taint)
         y.tainted?.should be_true
         y.first.tainted?.should be_false
       end
 
-      it "does not taint Integers" do
+      it "does not taint Bignums" do
         x = [bignum_value]
         y = Marshal.send(@method, Marshal.dump(x).taint)
         y.tainted?.should be_true
@@ -740,16 +740,16 @@ describe :marshal_load, shared: true do
     end
   end
 
-  describe "for an Integer" do
+  describe "for a Bignum" do
     platform_is wordsize: 64 do
-      context "that is Integer on 32-bit platforms but Integer on 64-bit" do
-        it "dumps an Integer" do
+      context "that is Bignum on 32-bit platforms but Fixnum on 64-bit" do
+        it "dumps a Fixnum" do
           val = Marshal.send(@method, "\004\bl+\ab:wU")
           val.should == 1433877090
           val.class.should == Integer
         end
 
-        it "dumps an array containing multiple references to the Integer as an array of Integer" do
+        it "dumps an array containing multiple references to the Bignum as an array of Fixnum" do
           arr = Marshal.send(@method, "\004\b[\al+\a\223BwU@\006")
           arr.should == [1433879187, 1433879187]
           arr.each { |v| v.class.should == Integer }
diff --git a/spec/ruby/core/method/shared/to_s.rb b/spec/ruby/core/method/shared/to_s.rb
index 8f7dd8c161..0dcae41b59 100644
--- a/spec/ruby/core/method/shared/to_s.rb
+++ b/spec/ruby/core/method/shared/to_s.rb
@@ -78,4 +78,12 @@ describe :method_to_s, shared: true do
     @string = @m.send(@method).sub(/0x\h+/, '0xXXXXXX')
     @string.should.start_with? "#<Method: #<MethodSpecs::MySub:0xXXXXXX>.bar"
   end
+
+  ruby_version_is '2.7' do
+    ruby_bug '#17428', '2.7'...'3.0' do
+      it "shows the metaclass and the owner for a Module instance method retrieved from a class" do
+        String.method(:include).inspect.should.start_with?("#<Method: #<Class:String>(Module)#include")
+      end
+    end
+  end
 end
diff --git a/spec/ruby/core/method/unbind_spec.rb b/spec/ruby/core/method/unbind_spec.rb
index 3d36c6d675..cdd3a808f2 100644
--- a/spec/ruby/core/method/unbind_spec.rb
+++ b/spec/ruby/core/method/unbind_spec.rb
@@ -14,20 +14,29 @@ describe "Method#unbind" do
     @normal_um.should be_kind_of(UnboundMethod)
   end
 
-  it "returns a String containing 'UnboundMethod'" do
-    @string.should =~ /\bUnboundMethod\b/
-  end
+  describe "#inspect" do
+    it "returns a String containing 'UnboundMethod'" do
+      @string.should =~ /\bUnboundMethod\b/
+    end
 
-  it "returns a String containing the method name" do
-    @string.should =~ /\#bar/
-  end
+    it "returns a String containing the method name" do
+      @string.should =~ /\#bar/
+    end
+
+    it "returns a String containing the Module the method is defined in" do
+      @string.should =~ /MethodSpecs::MyMod/
+    end
 
-  it "returns a String containing the Module the method is defined in" do
-    @string.should =~ /MethodSpecs::MyMod/
+    it "returns a String containing the Module the method is referenced from" do
+      @string.should =~ /MethodSpecs::MySub/
+    end
   end
 
-  it "returns a String containing the Module the method is referenced from" do
-    @string.should =~ /MethodSpecs::MySub/
+  it "keeps the origin singleton class if there is one" do
+    obj = Object.new
+    def obj.foo
+    end
+    obj.method(:foo).unbind.inspect.should.start_with?("#<UnboundMethod: #{obj.singleton_class}#foo")
   end
 
   specify "rebinding UnboundMethod to Method's obj produces exactly equivalent Methods" do
diff --git a/spec/ruby/core/numeric/denominator_spec.rb b/spec/ruby/core/numeric/denominator_spec.rb
index d347b280f5..34729446a2 100644
--- a/spec/ruby/core/numeric/denominator_spec.rb
+++ b/spec/ruby/core/numeric/denominator_spec.rb
@@ -6,7 +6,7 @@ describe "Numeric#denominator" do
   before :each do
     @numbers = [
       20,             # Integer
-      99999999**99,   # Integer
+      99999999**99,   # Bignum
     ]
   end
 
diff --git a/spec/ruby/core/numeric/quo_spec.rb b/spec/ruby/core/numeric/quo_spec.rb
index 33b68a38f0..5c952b11a9 100644
--- a/spec/ruby/core/numeric/quo_spec.rb
+++ b/spec/ruby/core/numeric/quo_spec.rb
@@ -11,7 +11,7 @@ describe "Numeric#quo" do
     2.quo(2.5).should eql(0.8)
   end
 
-  it "returns the result of self divided by the given Integer as a Float" do
+  it "returns the result of self divided by the given Bignum as a Float" do
     45.quo(bignum_value).should be_close(1.04773789668636e-08, TOLERANCE)
   end
 
diff --git a/spec/ruby/core/numeric/real_spec.rb b/spec/ruby/core/numeric/real_spec.rb
index 8702dcc7c2..2d2499bcce 100644
--- a/spec/ruby/core/numeric/real_spec.rb
+++ b/spec/ruby/core/numeric/real_spec.rb
@@ -7,7 +7,7 @@ describe "Numeric#real" do
       20,             # Integer
       398.72,         # Float
       Rational(3, 4), # Rational
-      bignum_value,   # Integer
+      bignum_value,   # Bignum
       infinity_value,
       nan_value
     ].map{ |n| [n, -n] }.flatten
diff --git a/spec/ruby/core/numeric/shared/imag.rb b/spec/ruby/core/numeric/shared/imag.rb
index 0b46b0020b..ac2da40a3b 100644
--- a/spec/ruby/core/numeric/shared/imag.rb
+++ b/spec/ruby/core/numeric/shared/imag.rb
@@ -6,7 +6,7 @@ describe :numeric_imag, shared: true do
       20,             # Integer
       398.72,         # Float
       Rational(3, 4), # Rational
-      bignum_value, # Integer
+      bignum_value, # Bignum
       infinity_value,
       nan_value
     ].map{|n| [n,-n]}.flatten
diff --git a/spec/ruby/core/numeric/shared/rect.rb b/spec/ruby/core/numeric/shared/rect.rb
index c56f3c48ae..9cde19a398 100644
--- a/spec/ruby/core/numeric/shared/rect.rb
+++ b/spec/ruby/core/numeric/shared/rect.rb
@@ -6,7 +6,7 @@ describe :numeric_rect, shared: true do
       20,             # Integer
       398.72,         # Float
       Rational(3, 4), # Rational
-      99999999**99, # Integer
+      99999999**99, # Bignum
       infinity_value,
       nan_value
     ]
diff --git a/spec/ruby/core/process/constants_spec.rb b/spec/ruby/core/process/constants_spec.rb
index 2fa93ad8bf..b61f5ab64e 100644
--- a/spec/ruby/core/process/constants_spec.rb
+++ b/spec/ruby/core/process/constants_spec.rb
@@ -60,4 +60,26 @@ describe "Process::Constants" do
       Process::RLIMIT_AS.should == 10
     end
   end
+
+  platform_is :windows do
+    it "does not define RLIMIT constants" do
+      %i[
+          RLIMIT_CPU
+          RLIMIT_FSIZE
+          RLIMIT_DATA
+          RLIMIT_STACK
+          RLIMIT_CORE
+          RLIMIT_RSS
+          RLIMIT_NPROC
+          RLIMIT_NOFILE
+          RLIMIT_MEMLOCK
+          RLIMIT_AS
+          RLIM_INFINITY
+          RLIM_SAVED_MAX
+          RLIM_SAVED_CUR
+      ].each do |const|
+        Process.const_defined?(const).should be_false
+      end
+    end
+  end
 end
diff --git a/spec/ruby/core/process/getrlimit_spec.rb b/spec/ruby/core/process/getrlimit_spec.rb
index f77a61a475..883b8fac48 100644
--- a/spec/ruby/core/process/getrlimit_spec.rb
+++ b/spec/ruby/core/process/getrlimit_spec.rb
@@ -11,8 +11,8 @@ platform_is :aix do
   Process.getrlimit(:DATA)
 end
 
-platform_is_not :windows do
-  describe "Process.getrlimit" do
+describe "Process.getrlimit" do
+  platform_is_not :windows do
     it "returns a two-element Array of Integers" do
       result = Process.getrlimit Process::RLIMIT_CORE
       result.size.should == 2
@@ -88,4 +88,13 @@ platform_is_not :windows do
       end
     end
   end
+
+  platform_is :windows do
+    it "is not implemented" do
+      Process.respond_to?(:getrlimit).should be_false
+      -> do
+        Process.getrlimit(nil)
+      end.should raise_error NotImplementedError
+    end
+  end
 end
diff --git a/spec/ruby/core/process/setrlimit_spec.rb b/spec/ruby/core/process/setrlimit_spec.rb
index 8bc035a4f1..b92f98fd40 100644
--- a/spec/ruby/core/process/setrlimit_spec.rb
+++ b/spec/ruby/core/process/setrlimit_spec.rb
@@ -1,7 +1,7 @@
 require_relative '../../spec_helper'
 
-platform_is_not :windows do
-  describe "Process.setrlimit" do
+describe "Process.setrlimit" do
+  platform_is_not :windows do
     context "when passed an Object" do
       before do
         @resource = Process::RLIMIT_CORE
@@ -229,4 +229,13 @@ platform_is_not :windows do
       end
     end
   end
+
+  platform_is :windows do
+    it "is not implemented" do
+      Process.respond_to?(:setrlimit).should be_false
+      -> do
+        Process.setrlimit(nil, nil)
+      end.should raise_error NotImplementedError
+    end
+  end
 end
diff --git a/spec/ruby/core/random/rand_spec.rb b/spec/ruby/core/random/rand_spec.rb
index 7fd60d5553..6ea7eece5f 100644
--- a/spec/ruby/core/random/rand_spec.rb
+++ b/spec/ruby/core/random/rand_spec.rb
@@ -49,18 +49,18 @@ describe "Random.rand" do
   end
 end
 
-describe "Random#rand with Integer" do
+describe "Random#rand with Fixnum" do
   it "returns an Integer" do
     Random.new.rand(20).should be_an_instance_of(Integer)
   end
 
-  it "returns an Integer greater than or equal to 0" do
+  it "returns a Fixnum greater than or equal to 0" do
     prng = Random.new
     ints = 20.times.map { prng.rand(5) }
     ints.min.should >= 0
   end
 
-  it "returns an Integer less than the argument" do
+  it "returns a Fixnum less than the argument" do
     prng = Random.new
     ints = 20.times.map { prng.rand(5) }
     ints.max.should <= 4
@@ -92,19 +92,19 @@ describe "Random#rand with Integer" do
   end
 end
 
-describe "Random#rand with Integer" do
-  it "typically returns an Integer" do
+describe "Random#rand with Bignum" do
+  it "typically returns a Bignum" do
     rnd = Random.new(1)
     10.times.map{ rnd.rand(bignum_value*2) }.max.should be_an_instance_of(Integer)
   end
 
-  it "returns an Integer greater than or equal to 0" do
+  it "returns a Bignum greater than or equal to 0" do
     prng = Random.new
     bigs = 20.times.map { prng.rand(bignum_value) }
     bigs.min.should >= 0
   end
 
-  it "returns an Integer less than the argument" do
+  it "returns a Bignum less than the argument" do
     prng = Random.new
     bigs = 20.times.map { prng.rand(bignum_value) }
     bigs.max.should < bignum_value
diff --git a/spec/ruby/core/range/bsearch_spec.rb b/spec/ruby/core/range/bsearch_spec.rb
index 38ccd35170..d31c5d5d51 100644
--- a/spec/ruby/core/range/bsearch_spec.rb
+++ b/spec/ruby/core/range/bsearch_spec.rb
@@ -126,8 +126,8 @@ describe "Range#bsearch" do
         inf = Float::INFINITY
         (0..inf).bsearch { |x| x == inf }.should == inf
         (0...inf).bsearch { |x| x == inf }.should == nil
-        (-inf..0).bsearch { |x| x == -inf }.should == nil
-        (-inf...0).bsearch { |x| x == -inf }.should == nil
+        (-inf..0).bsearch { |x| x != -inf }.should == -Float::MAX
+        (-inf...0).bsearch { |x| x != -inf }.should == -Float::MAX
         (inf..inf).bsearch { |x| true }.should == inf
         (inf...inf).bsearch { |x| true }.should == nil
         (-inf..-inf).bsearch { |x| true }.should == -inf
@@ -194,10 +194,10 @@ describe "Range#bsearch" do
 
       it "works with infinity bounds" do
         inf = Float::INFINITY
-        (0..inf).bsearch { |x| x == inf ? 0 : -1 }.should == nil
-        (0...inf).bsearch { |x| x == inf ? 0 : -1 }.should == nil
-        (-inf...0).bsearch { |x| x == -inf ? 0 : 1 }.should == nil
-        (-inf..0).bsearch { |x| x == -inf ? 0 : 1 }.should == nil
+        (0..inf).bsearch { |x| x == inf ? 0 : 1 }.should == inf
+        (0...inf).bsearch { |x| x == inf ? 0 : 1 }.should == nil
+        (-inf...0).bsearch { |x| x == -inf ? 0 : -1 }.should == -inf
+        (-inf..0).bsearch { |x| x == -inf ? 0 : -1 }.should == -inf
         (inf..inf).bsearch { 0 }.should == inf
         (inf...inf).bsearch { 0 }.should == nil
         (-inf..-inf).bsearch { 0 }.should == -inf
@@ -248,7 +248,7 @@ describe "Range#bsearch" do
 
         it "returns an element at an index for which block returns 0" do
           result = eval("(0..)").bsearch { |x| x < 1 ? 1 : x > 3 ? -1 : 0 }
-          [1, 2].should include(result)
+          [1, 2, 3].should include(result)
         end
       end
     end
@@ -330,4 +330,111 @@ describe "Range#bsearch" do
       end
     end
   end
+
+
+  ruby_version_is "2.7" do
+    context "with beginless ranges and Integer values" do
+      context "with a block returning true or false" do
+        it "returns the smallest element for which block returns true" do
+          eval("(..10)").bsearch { |x| x >= 2 }.should == 2
+          eval("(...-1)").bsearch { |x| x >= -10 }.should == -10
+        end
+      end
+
+      context "with a block returning negative, zero, positive numbers" do
+        it "returns nil if the block returns greater than zero for every element" do
+          eval("(..0)").bsearch { |x| 1 }.should be_nil
+        end
+
+        it "returns nil if the block never returns zero" do
+          eval("(..0)").bsearch { |x| x > 5 ? -1 : 1 }.should be_nil
+        end
+
+        it "accepts Float::INFINITY from the block" do
+          eval("(..0)").bsearch { |x| Float::INFINITY }.should be_nil
+        end
+
+        it "returns an element at an index for which block returns 0.0" do
+          result = eval("(..10)").bsearch { |x| x < 2 ? 1.0 : x > 2 ? -1.0 : 0.0 }
+          result.should == 2
+        end
+
+        it "returns an element at an index for which block returns 0" do
+          result = eval("(...10)").bsearch { |x| x < 1 ? 1 : x > 3 ? -1 : 0 }
+          [1, 2, 3].should include(result)
+        end
+      end
+    end
+
+    context "with beginless ranges and Float values" do
+      context "with a block returning true or false" do
+        it "returns nil if the block returns true for every element" do
+          eval("(..-0.1)").bsearch { |x| x > 0.0 }.should be_nil
+          eval("(...-0.1)").bsearch { |x| x > 0.0 }.should be_nil
+        end
+
+        it "returns nil if the block returns nil for every element" do
+          eval("(..-0.1)").bsearch { |x| nil }.should be_nil
+          eval("(...-0.1)").bsearch { |x| nil }.should be_nil
+        end
+
+        it "returns the smallest element for which block returns true" do
+          eval("(..10)").bsearch { |x| x >= 2 }.should == 2
+          eval("(..10)").bsearch { |x| x >= 1 }.should == 1
+        end
+
+        it "works with infinity bounds" do
+          inf = Float::INFINITY
+          eval("(..inf)").bsearch { |x| true }.should == -inf
+          eval("(...inf)").bsearch { |x| true }.should == -inf
+          eval("(..-inf)").bsearch { |x| true }.should == -inf
+          eval("(...-inf)").bsearch { |x| true }.should == nil
+        end
+      end
+
+      context "with a block returning negative, zero, positive numbers" do
+        it "returns nil if the block returns less than zero for every element" do
+          eval("(..5.0)").bsearch { |x| -1 }.should be_nil
+          eval("(...5.0)").bsearch { |x| -1 }.should be_nil
+        end
+
+        it "returns nil if the block returns greater than zero for every element" do
+          eval("(..1.1)").bsearch { |x| 1 }.should be_nil
+          eval("(...1.1)").bsearch { |x| 1 }.should be_nil
+        end
+
+        it "returns nil if the block never returns zero" do
+          eval("(..6.3)").bsearch { |x| x < 2 ? 1 : -1 }.should be_nil
+        end
+
+        it "accepts (+/-)Float::INFINITY from the block" do
+          eval("(..5.0)").bsearch { |x| Float::INFINITY }.should be_nil
+          eval("(..7.0)").bsearch { |x| -Float::INFINITY }.should be_nil
+        end
+
+        it "returns an element at an index for which block returns 0.0" do
+          result = eval("(..8.0)").bsearch { |x| x < 2 ? 1.0 : x > 2 ? -1.0 : 0.0 }
+          result.should == 2
+        end
+
+        it "returns an element at an index for which block returns 0" do
+          result = eval("(..8.0)").bsearch { |x| x < 1 ? 1 : x > 3 ? -1 : 0 }
+          result.should >= 1
+          result.should <= 3
+        end
+
+        it "works with infinity bounds" do
+          inf = Float::INFINITY
+          eval("(..-inf)").bsearch { |x| 1 }.should == nil
+          eval("(...-inf)").bsearch { |x| 1 }.should == nil
+          eval("(..inf)").bsearch { |x| x == inf ? 0 : 1 }.should == inf
+          eval("(...inf)").bsearch { |x| x == inf ? 0 : 1 }.should == nil
+          eval("(..-inf)").bsearch { |x| x == -inf ? 0 : -1 }.should == -inf
+          eval("(...-inf)").bsearch { |x| x == -inf ? 0 : -1 }.should == nil
+          eval("(..inf)").bsearch { |x| 3 - x }.should == 3
+          eval("(...inf)").bsearch { |x| 3 - x }.should == 3
+        end
+      end
+    end
+  end
 end
diff --git a/spec/ruby/core/range/count_spec.rb b/spec/ruby/core/range/count_spec.rb
new file mode 100644
index 0000000000..f6f60fa054
--- /dev/null
+++ b/spec/ruby/core/range/count_spec.rb
@@ -0,0 +1,14 @@
+require_relative '../../spec_helper'
+
+describe "Range#count" do
+  ruby_version_is "2.7" do
+    it "returns Infinity for beginless ranges without arguments or blocks" do
+      inf = Float::INFINITY
+      eval("('a'...)").count.should == inf
+      eval("(7..)").count.should == inf
+      eval("(...'a')").count.should == inf
+      eval("(...nil)").count.should == inf
+      eval("(..10.0)").count.should == inf
+    end
+  end
+end
diff --git a/spec/ruby/core/range/each_spec.rb b/spec/ruby/core/range/each_spec.rb
index 8935d86829..1dce9c1f1e 100644
--- a/spec/ruby/core/range/each_spec.rb
+++ b/spec/ruby/core/range/each_spec.rb
@@ -32,6 +32,12 @@ describe "Range#each" do
     a.should == [x, y]
   end
 
+  it "works for non-ASCII ranges" do
+    a = []
+    ('Σ'..'Ω').each { |i| a << i }
+    a.should == ["Σ", "Τ", "Υ", "Φ", "Χ", "Ψ", "Ω"]
+  end
+
   ruby_version_is "2.6" do
     it "works with endless ranges" do
       a = []
@@ -54,6 +60,12 @@ describe "Range#each" do
     end
   end
 
+  ruby_version_is "2.7" do
+    it "raises a TypeError beginless ranges" do
+      -> { eval("(..2)").each { |x| x } }.should raise_error(TypeError)
+    end
+  end
+
   it "raises a TypeError if the first element does not respond to #succ" do
     -> { (0.5..2.4).each { |i| i } }.should raise_error(TypeError)
 
diff --git a/spec/ruby/core/range/equal_value_spec.rb b/spec/ruby/core/range/equal_value_spec.rb
index 43d5e0e38a..f88d3029bb 100644
--- a/spec/ruby/core/range/equal_value_spec.rb
+++ b/spec/ruby/core/range/equal_value_spec.rb
@@ -13,4 +13,10 @@ describe "Range#==" do
       eval("(1.0..)").should == eval("(1.0..)")
     end
   end
+
+  ruby_version_is "2.7" do
+    it "returns true if the endpoints are == for beginless ranges" do
+      eval("(...10)").should == eval("(...10)")
+    end
+  end
 end
diff --git a/spec/ruby/core/range/first_spec.rb b/spec/ruby/core/range/first_spec.rb
index 5f073b48ee..c5c90800ac 100644
--- a/spec/ruby/core/range/first_spec.rb
+++ b/spec/ruby/core/range/first_spec.rb
@@ -46,4 +46,10 @@ describe "Range#first" do
   it "raises a TypeError when passed a String" do
     -> { (2..3).first("1") }.should raise_error(TypeError)
   end
+
+  ruby_version_is "2.7" do
+    it "raises a RangeError when called on an beginless range" do
+      -> { eval("(..1)").first }.should raise_error(RangeError)
+    end
+  end
 end
diff --git a/spec/ruby/core/range/inspect_spec.rb b/spec/ruby/core/range/inspect_spec.rb
index d1072531e9..6a206a0355 100644
--- a/spec/ruby/core/range/inspect_spec.rb
+++ b/spec/ruby/core/range/inspect_spec.rb
@@ -19,6 +19,18 @@ describe "Range#inspect" do
     end
   end
 
+  ruby_version_is '2.7' do
+    it "works for beginless ranges" do
+      eval("(..1)").inspect.should ==  "..1"
+      eval("(...0.1)").inspect.should ==  "...0.1"
+    end
+
+    it "works for nil ... nil ranges" do
+      eval("(..nil)").inspect.should ==  "nil..nil"
+      eval("(nil...)").inspect.should ==  "nil...nil"
+    end
+  end
+
   ruby_version_is ''...'2.7' do
     it "returns a tainted string if either end is tainted" do
       (("a".taint)..."c").inspect.tainted?.should be_true
diff --git a/spec/ruby/core/range/max_spec.rb b/spec/ruby/core/range/max_spec.rb
index 728053cefd..f2672170d9 100644
--- a/spec/ruby/core/range/max_spec.rb
+++ b/spec/ruby/core/range/max_spec.rb
@@ -51,6 +51,19 @@ describe "Range#max" do
       -> { eval("(1..)").max }.should raise_error(RangeError)
     end
   end
+
+  ruby_version_is "3.0" do
+    it "returns the end point for beginless ranges" do
+      eval("(..1)").max.should == 1
+      eval("(..1.0)").max.should == 1.0
+    end
+
+    it "raises for an exclusive beginless range" do
+      -> {
+        eval("(...1)").max
+      }.should raise_error(TypeError, 'cannot exclude end value with non Integer begin value')
+    end
+  end
 end
 
 describe "Range#max given a block" do
@@ -85,4 +98,10 @@ describe "Range#max given a block" do
     ('z'..'l').max {|x,y| x <=> y}.should be_nil
     (5...5).max {|x,y| x <=> y}.should be_nil
   end
+
+  ruby_version_is "2.7" do
+    it "raises RangeError when called with custom comparison method on an beginless range" do
+      -> { eval("(..1)").max {|a, b| a} }.should raise_error(RangeError)
+    end
+  end
 end
diff --git a/spec/ruby/core/range/min_spec.rb b/spec/ruby/core/range/min_spec.rb
index f1dff73e6d..ffd40f3a07 100644
--- a/spec/ruby/core/range/min_spec.rb
+++ b/spec/ruby/core/range/min_spec.rb
@@ -38,6 +38,19 @@ describe "Range#min" do
     time_end = Time.now + 1.0
     (time_start...time_end).min.should equal(time_start)
   end
+
+  ruby_version_is "2.6" do
+    it "returns the start point for endless ranges" do
+      eval("(1..)").min.should == 1
+      eval("(1.0...)").min.should == 1.0
+    end
+  end
+
+  ruby_version_is "2.7" do
+    it "raises RangeError when called on an beginless range" do
+      -> { eval("(..1)").min }.should raise_error(RangeError)
+    end
+  end
 end
 
 describe "Range#min given a block" do
@@ -74,9 +87,8 @@ describe "Range#min given a block" do
   end
 
   ruby_version_is "2.6" do
-    it "returns the start point for endless ranges" do
-      eval("(1..)").min.should == 1
-      eval("(1.0...)").min.should == 1.0
+    it "raises RangeError when called with custom comparison method on an endless range" do
+      -> { eval("(1..)").min {|a, b| a} }.should raise_error(RangeError)
     end
   end
 end
diff --git a/spec/ruby/core/range/size_spec.rb b/spec/ruby/core/range/size_spec.rb
index b687342b72..4bf525e541 100644
--- a/spec/ruby/core/range/size_spec.rb
+++ b/spec/ruby/core/range/size_spec.rb
@@ -25,10 +25,24 @@ describe "Range#size" do
   end
 
   ruby_version_is "2.6" do
-    it 'returns Float::INFINITY for endless ranges' do
+    it 'returns Float::INFINITY for endless ranges if the start is numeric' do
       eval("(1..)").size.should == Float::INFINITY
       eval("(0.5...)").size.should == Float::INFINITY
     end
+
+    it 'returns nil for endless ranges if the start is not numeric' do
+      eval("('z'..)").size.should == nil
+      eval("([]...)").size.should == nil
+    end
+  end
+
+  ruby_version_is "2.7" do
+    it 'returns Float::INFINITY for all beginless ranges' do
+      eval("(..1)").size.should == Float::INFINITY
+      eval("(...0.5)").size.should == Float::INFINITY
+      eval("(..nil)").size.should == Float::INFINITY
+      eval("(...'o')").size.should == Float::INFINITY
+    end
   end
 
   it "returns nil if first and last are not Numeric" do
diff --git a/spec/ruby/core/range/to_a_spec.rb b/spec/ruby/core/range/to_a_spec.rb
index b0067f0e07..08f50e4d9e 100644
--- a/spec/ruby/core/range/to_a_spec.rb
+++ b/spec/ruby/core/range/to_a_spec.rb
@@ -20,9 +20,19 @@ describe "Range#to_a" do
     (:A..:z).to_a.size.should == 58
   end
 
+  it "works for non-ASCII ranges" do
+    ('Σ'..'Ω').to_a.should == ["Σ", "Τ", "Υ", "Φ", "Χ", "Ψ", "Ω"]
+  end
+
   ruby_version_is "2.6" do
     it "throws an exception for endless ranges" do
       -> { eval("(1..)").to_a }.should raise_error(RangeError)
     end
   end
+
+  ruby_version_is "2.7" do
+    it "throws an exception for beginless ranges" do
+      -> { eval("(..1)").to_a }.should raise_error(TypeError)
+    end
+  end
 end
diff --git a/spec/ruby/core/regexp/last_match_spec.rb b/spec/ruby/core/regexp/last_match_spec.rb
index 6bd8f2cd90..0bfed32051 100644
--- a/spec/ruby/core/regexp/last_match_spec.rb
+++ b/spec/ruby/core/regexp/last_match_spec.rb
@@ -11,4 +11,46 @@ describe "Regexp.last_match" do
     /c(.)t/ =~ 'cat'
     Regexp.last_match(1).should == 'a'
   end
+
+  it "returns nil when there is no match" do
+    /foo/ =~ "TEST123"
+    Regexp.last_match(:test).should == nil
+    Regexp.last_match(1).should == nil
+    Regexp.last_match(Object.new).should == nil
+    Regexp.last_match("test").should == nil
+  end
+
+  describe "when given a Symbol" do
+    it "returns a named capture" do
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      Regexp.last_match(:test).should == "TEST123"
+    end
+
+    it "raises an IndexError when given a missing name" do
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      -> { Regexp.last_match(:missing) }.should raise_error(IndexError)
+    end
+  end
+
+  describe "when given a String" do
+    it "returns a named capture" do
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      Regexp.last_match("test").should == "TEST123"
+    end
+  end
+
+  describe "when given an Object" do
+    it "coerces argument to an index using #to_int" do
+      obj = mock("converted to int")
+      obj.should_receive(:to_int).and_return(1)
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      Regexp.last_match(obj).should == "TEST123"
+    end
+
+    it "raises a TypeError when unable to coerce" do
+      obj = Object.new
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      -> { Regexp.last_match(obj) }.should raise_error(TypeError)
+    end
+  end
 end
diff --git a/spec/ruby/core/string/upto_spec.rb b/spec/ruby/core/string/upto_spec.rb
index b988613a80..f8529b1d2b 100644
--- a/spec/ruby/core/string/upto_spec.rb
+++ b/spec/ruby/core/string/upto_spec.rb
@@ -74,6 +74,12 @@ describe "String#upto" do
     a.should == ["a", "b", "c"]
   end
 
+  it "works with non-ASCII ranges" do
+    a = []
+    'Σ'.upto('Ω') { |s| a << s }
+    a.should == ["Σ", "Τ", "Υ", "Φ", "Χ", "Ψ", "Ω"]
+  end
+
   describe "on sequence of numbers" do
     it "calls the block as Integer#upto"  do
       "8".upto("11").to_a.should == 8.upto(11).map(&:to_s)
diff --git a/spec/ruby/core/struct/deconstruct_keys_spec.rb b/spec/ruby/core/struct/deconstruct_keys_spec.rb
index 41b9c31e02..f0a1f50ad3 100644
--- a/spec/ruby/core/struct/deconstruct_keys_spec.rb
+++ b/spec/ruby/core/struct/deconstruct_keys_spec.rb
@@ -43,11 +43,19 @@ ruby_version_is "2.7" do
       s.deconstruct_keys([0]      ).should == {0 => 10}
     end
 
-    it "ignores not existing attribute names" do
+    it "returns an empty hash when there are more keys than attributes" do
       struct = Struct.new(:x, :y)
       s = struct.new(1, 2)
 
-      s.deconstruct_keys([:a, :b, :c]).should == {}
+      s.deconstruct_keys([:x, :y, :a]).should == {}
+    end
+
+    it "returns at first not existing attribute name" do
+      struct = Struct.new(:x, :y)
+      s = struct.new(1, 2)
+
+      s.deconstruct_keys([:a, :x]).should == {}
+      s.deconstruct_keys([:x, :a]).should == {x: 1}
     end
 
     it "accepts nil argument and return all the attributes" do
diff --git a/spec/ruby/language/defined_spec.rb b/spec/ruby/language/defined_spec.rb
index 4fcf869f91..f2da8a9293 100644
--- a/spec/ruby/language/defined_spec.rb
+++ b/spec/ruby/language/defined_spec.rb
@@ -435,11 +435,11 @@ describe "The defined? keyword for an expression" do
     end
   end
 
-  it "returns 'expression' when passed an Integer literal" do
+  it "returns 'expression' when passed a Fixnum literal" do
     defined?(42).should == "expression"
   end
 
-  it "returns 'expression' when passed an Integer literal" do
+  it "returns 'expression' when passed a Bignum literal" do
     defined?(0xdead_beef_deed_feed).should == "expression"
   end
 
diff --git a/spec/ruby/language/numbered_parameters_spec.rb b/spec/ruby/language/numbered_parameters_spec.rb
index b05c373a68..cd1ddf4555 100644
--- a/spec/ruby/language/numbered_parameters_spec.rb
+++ b/spec/ruby/language/numbered_parameters_spec.rb
@@ -29,7 +29,7 @@ ruby_version_is "2.7" do
     it "can not be used in both outer and nested blocks at the same time" do
       -> {
         eval("-> { _1; -> { _2 } }")
-      }.should raise_error(SyntaxError, /numbered parameter is already used in.+ outer block here/m)
+      }.should raise_error(SyntaxError, /numbered parameter is already used in/m)
     end
 
     ruby_version_is '2.7'...'3.0' do
diff --git a/spec/ruby/language/pattern_matching_spec.rb b/spec/ruby/language/pattern_matching_spec.rb
index edc3826448..dae2828bf6 100644
--- a/spec/ruby/language/pattern_matching_spec.rb
+++ b/spec/ruby/language/pattern_matching_spec.rb
@@ -5,7 +5,7 @@ ruby_version_is "2.7" do
     # TODO: Remove excessive eval calls when support of previous version
     #       Ruby 2.6 will be dropped
 
-    before do
+    before :each do
       ScratchPad.record []
     end
 
@@ -41,7 +41,7 @@ ruby_version_is "2.7" do
     end
 
     describe "warning" do
-      before do
+      before :each do
         ruby_version_is ""..."3.0" do
           @src = 'case [0, 1]; in [a, b]; end'
         end
@@ -49,6 +49,12 @@ ruby_version_is "2.7" do
         ruby_version_is "3.0" do
           @src = '[0, 1] => [a, b]'
         end
+
+        @experimental, Warning[:experimental] = Warning[:experimental], true
+      end
+
+      after :each do
+        Warning[:experimental] = @experimental
       end
 
       it "warns about pattern matching is experimental feature" do
@@ -130,6 +136,19 @@ ruby_version_is "2.7" do
       }.should raise_error(SyntaxError, /unexpected/)
     end
 
+    it "evaluates the case expression once for multiple patterns, caching the result" do
+      eval(<<~RUBY).should == true
+        case (ScratchPad << :foo; 1)
+        in 0
+          false
+        in 1
+          true
+        end
+      RUBY
+
+      ScratchPad.recorded.should == [:foo]
+    end
+
     describe "guards" do
       it "supports if guard" do
         eval(<<~RUBY).should == false
@@ -508,6 +527,47 @@ ruby_version_is "2.7" do
         RUBY
       end
 
+      ruby_version_is "3.0" do
+        it "calls #deconstruct once for multiple patterns, caching the result" do
+          obj = Object.new
+
+          def obj.deconstruct
+            ScratchPad << :deconstruct
+            [0, 1]
+          end
+
+          eval(<<~RUBY).should == true
+            case obj
+            in [1, 2]
+              false
+            in [0, 1]
+              true
+            end
+          RUBY
+
+          ScratchPad.recorded.should == [:deconstruct]
+        end
+      end
+
+      it "calls #deconstruct even on objects that are already an array" do
+        obj = [1, 2]
+        def obj.deconstruct
+          ScratchPad << :deconstruct
+          [3, 4]
+        end
+
+        eval(<<~RUBY).should == true
+          case obj
+          in [3, 4]
+            true
+          else
+            false
+          end
+        RUBY
+
+        ScratchPad.recorded.should == [:deconstruct]
+      end
+
       it "does not match object if Constant === object returns false" do
         eval(<<~RUBY).should == false
           case [0, 1, 2]
@@ -521,6 +581,7 @@ ruby_version_is "2.7" do
 
       it "does not match object without #deconstruct method" do
         obj = Object.new
+        obj.should_receive(:respond_to?).with(:deconstruct)
 
         eval(<<~RUBY).should == false
           case obj
@@ -546,6 +607,26 @@ ruby_version_is "2.7" do
         }.should raise_error(TypeError, /deconstruct must return Array/)
       end
 
+      it "accepts a subclass of Array from #deconstruct" do
+        obj = Object.new
+        def obj.deconstruct
+          subarray = Class.new(Array).new(2)
+          def subarray.[](n)
+            n
+          end
+          subarray
+        end
+
+        eval(<<~RUBY).should == true
+          case obj
+          in [1, 2]
+            false
+          in [0, 1]
+            true
+          end
+        RUBY
+      end
+
       it "does not match object if elements of array returned by #deconstruct method does not match elements in pattern" do
         obj = Object.new
         def obj.deconstruct; [1] end
@@ -778,6 +859,26 @@ ruby_version_is "2.7" do
         RUBY
       end
 
+      it "calls #deconstruct_keys per pattern" do
+        obj = Object.new
+
+        def obj.deconstruct_keys(*)
+          ScratchPad << :deconstruct_keys
+          {a: 1}
+        end
+
+        eval(<<~RUBY).should == true
+          case obj
+          in {b: 1}
+            false
+          in {a: 1}
+            true
+          end
+        RUBY
+
+        ScratchPad.recorded.should == [:deconstruct_keys, :deconstruct_keys]
+      end
+
       it "does not match object if Constant === object returns false" do
         eval(<<~RUBY).should == false
           case {a: 1}
@@ -791,6 +892,7 @@ ruby_version_is "2.7" do
 
       it "does not match object without #deconstruct_keys method" do
         obj = Object.new
+        obj.should_receive(:respond_to?).with(:deconstruct_keys)
 
         eval(<<~RUBY).should == false
           case obj
diff --git a/spec/ruby/language/regexp/back-references_spec.rb b/spec/ruby/language/regexp/back-references_spec.rb
index 81015ac21e..e8df8725c5 100644
--- a/spec/ruby/language/regexp/back-references_spec.rb
+++ b/spec/ruby/language/regexp/back-references_spec.rb
@@ -47,7 +47,89 @@ describe "Regexps with back-references" do
     /(a\1?){2}/.match("aaaa").to_a.should == ["aa", "a"]
   end
 
+  it "does not reset enclosed capture groups" do
+    /((a)|(b))+/.match("ab").captures.should == [ "b", "a", "b" ]
+  end
+
   it "can match an optional quote, followed by content, followed by a matching quote, as the whole string" do
     /^("|)(.*)\1$/.match('x').to_a.should == ["x", "", "x"]
   end
+
+  it "allows forward references" do
+    /(?:(\2)|(.))+/.match("aa").to_a.should == [ "aa", "a", "a" ]
+  end
+
+  it "disallows forward references >= 10" do
+    (/\10()()()()()()()()()()/ =~ "\x08").should == 0
+  end
+
+  it "ignores backreferences > 1000" do
+    /\99999/.match("99999")[0].should == "99999"
+  end
+
+  it "0 is not a valid backreference" do
+    -> { Regexp.new("\\k<0>") }.should raise_error(RegexpError)
+  end
+
+  it "allows numeric conditional backreferences" do
+    /(a)(?(1)a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?(<1>)a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?('1')a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+  end
+
+  it "allows either <> or '' in named conditional backreferences" do
+    -> { Regexp.new("(?<a>a)(?(a)a|b)") }.should raise_error(RegexpError)
+    /(?<a>a)(?(<a>)a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+    /(?<a>a)(?('a')a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+  end
+
+  it "allows negative numeric backreferences" do
+    /(a)\k<-1>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)\g<-1>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?(<-1>)a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?('-1')a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+  end
+
+  it "delimited numeric backreferences can start with 0" do
+    /(a)\k<01>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)\g<01>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?(01)a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?(<01>)a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+    /(a)(?('01')a|b)/.match("aa").to_a.should == [ "aa", "a" ]
+  end
+
+  it "regular numeric backreferences cannot start with 0" do
+    /(a)\01/.match("aa").should == nil
+    /(a)\01/.match("a\x01").to_a.should == [ "a\x01", "a" ]
+  end
+
+  it "named capture groups invalidate numeric backreferences" do
+    -> { Regexp.new("(?<a>a)\\1") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a>a)\\k<1>") }.should raise_error(RegexpError)
+    -> { Regexp.new("(a)(?<a>a)\\1") }.should raise_error(RegexpError)
+    -> { Regexp.new("(a)(?<a>a)\\k<1>") }.should raise_error(RegexpError)
+  end
+
+  it "treats + or - as the beginning of a level specifier in \\k<> backreferences and (?(...)...|...) conditional backreferences" do
+    -> { Regexp.new("(?<a+>a)\\k<a+>") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a+b>a)\\k<a+b>") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a+1>a)\\k<a+1>") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a->a)\\k<a->") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a-b>a)\\k<a-b>") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a-1>a)\\k<a-1>") }.should raise_error(RegexpError)
+
+    -> { Regexp.new("(?<a+>a)(?(<a+>)a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a+b>a)(?(<a+b>)a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a+1>a)(?(<a+1>)a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a->a)(?(<a->)a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a-b>a)(?(<a-b>)a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a-1>a)(?(<a-1>)a|b)") }.should raise_error(RegexpError)
+
+    -> { Regexp.new("(?<a+>a)(?('a+')a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a+b>a)(?('a+b')a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a+1>a)(?('a+1')a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a->a)(?('a-')a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a-b>a)(?('a-b')a|b)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<a-1>a)(?('a-1')a|b)") }.should raise_error(RegexpError)
+  end
 end
diff --git a/spec/ruby/language/regexp/escapes_spec.rb b/spec/ruby/language/regexp/escapes_spec.rb
index 14e1424d47..2e5fe5ad2e 100644
--- a/spec/ruby/language/regexp/escapes_spec.rb
+++ b/spec/ruby/language/regexp/escapes_spec.rb
@@ -78,4 +78,20 @@ describe "Regexps with escape characters" do
     # \M-x         meta  (x|0x80)        (character code point value)
     # \M-\C-x      meta control char     (character code point value)
   end
+
+  it "handles three digit octal escapes starting with 0" do
+    /[\000-\b]/.match("\x00")[0].should == "\x00"
+  end
+
+  it "handles control escapes with \\C-x syntax" do
+    /\C-*\C-J\C-j/.match("\n\n\n")[0].should == "\n\n\n"
+  end
+
+  it "supports the \\K keep operator" do
+    /a\Kb/.match("ab")[0].should == "b"
+  end
+
+  it "supports the \\R line break escape" do
+    /\R/.match("\n")[0].should == "\n"
+  end
 end
diff --git a/spec/ruby/language/regexp/grouping_spec.rb b/spec/ruby/language/regexp/grouping_spec.rb
index 8806d06746..2fecf2d2cb 100644
--- a/spec/ruby/language/regexp/grouping_spec.rb
+++ b/spec/ruby/language/regexp/grouping_spec.rb
@@ -20,4 +20,9 @@ describe "Regexps with grouping" do
     # Parsing precedence
     /(?:xdigit:)/.match("xdigit:").to_a.should == ["xdigit:"]
   end
+
+  it "group names cannot start with digits or minus" do
+    -> { Regexp.new("(?<1a>a)") }.should raise_error(RegexpError)
+    -> { Regexp.new("(?<-a>a)") }.should raise_error(RegexpError)
+  end
 end
diff --git a/spec/ruby/language/regexp/repetition_spec.rb b/spec/ruby/language/regexp/repetition_spec.rb
index 7bb767ccaf..295b3bf553 100644
--- a/spec/ruby/language/regexp/repetition_spec.rb
+++ b/spec/ruby/language/regexp/repetition_spec.rb
@@ -45,4 +45,87 @@ describe "Regexps with repetition" do
     /a?/.match("aaa").to_a.should == ["a"]
     /a?/.match("bbb").to_a.should == [""]
   end
+
+  it "handles incomplete range quantifiers" do
+    /a{}/.match("a{}")[0].should == "a{}"
+    /a{,}/.match("a{,}")[0].should == "a{,}"
+    /a{1/.match("a{1")[0].should == "a{1"
+    /a{1,2/.match("a{1,2")[0].should == "a{1,2"
+    /a{,5}/.match("aaa")[0].should == "aaa"
+  end
+
+  it "lets us use quantifiers on assertions" do
+    /a^?b/.match("ab")[0].should == "ab"
+    /a$?b/.match("ab")[0].should == "ab"
+    /a\A?b/.match("ab")[0].should == "ab"
+    /a\Z?b/.match("ab")[0].should == "ab"
+    /a\z?b/.match("ab")[0].should == "ab"
+    /a\G?b/.match("ab")[0].should == "ab"
+    /a\b?b/.match("ab")[0].should == "ab"
+    /a\B?b/.match("ab")[0].should == "ab"
+    /a(?=c)?b/.match("ab")[0].should == "ab"
+    /a(?!=b)?b/.match("ab")[0].should == "ab"
+    /a(?<=c)?b/.match("ab")[0].should == "ab"
+    /a(?<!a)?b/.match("ab")[0].should == "ab"
+  end
+
+  it "does not delete optional assertions" do
+    /(?=(a))?/.match("a").to_a.should == [ "", "a" ]
+  end
+
+  it "supports nested quantifiers" do
+    suppress_warning do
+      eval <<-RUBY
+      /a***/.match("aaa")[0].should == "aaa"
+
+      # a+?* should not be reduced, it should be equivalent to (a+?)*
+      # NB: the capture group prevents regex engines from reducing the two quantifiers
+      # https://bugs.ruby-lang.org/issues/17341
+      /a+?*/.match("")[0].should == ""
+      /(a+?)*/.match("")[0].should == ""
+
+      /a+?*/.match("a")[0].should == "a"
+      /(a+?)*/.match("a")[0].should == "a"
+
+      ruby_bug '#17341', ''...'3.0' do
+        /a+?*/.match("aa")[0].should == "aa"
+      end
+      /(a+?)*/.match("aa")[0].should == "aa"
+
+      # a+?+ should not be reduced, it should be equivalent to (a+?)+
+      # https://bugs.ruby-lang.org/issues/17341
+      /a+?+/.match("").should == nil
+      /(a+?)+/.match("").should == nil
+
+      /a+?+/.match("a")[0].should == "a"
+      /(a+?)+/.match("a")[0].should == "a"
+
+      ruby_bug '#17341', ''...'3.0' do
+        /a+?+/.match("aa")[0].should == "aa"
+      end
+      /(a+?)+/.match("aa")[0].should == "aa"
+
+      # both a**? and a+*? should be equivalent to (a+)??
+      # this quantifier would rather match nothing, but if that's not possible,
+      # it will greedily take everything
+      /a**?/.match("")[0].should == ""
+      /(a*)*?/.match("")[0].should == ""
+      /a+*?/.match("")[0].should == ""
+      /(a+)*?/.match("")[0].should == ""
+      /(a+)??/.match("")[0].should == ""
+
+      /a**?/.match("aaa")[0].should == ""
+      /(a*)*?/.match("aaa")[0].should == ""
+      /a+*?/.match("aaa")[0].should == ""
+      /(a+)*?/.match("aaa")[0].should == ""
+      /(a+)??/.match("aaa")[0].should == ""
+
+      /b.**?b/.match("baaabaaab")[0].should == "baaabaaab"
+      /b(.*)*?b/.match("baaabaaab")[0].should == "baaabaaab"
+      /b.+*?b/.match("baaabaaab")[0].should == "baaabaaab"
+      /b(.+)*?b/.match("baaabaaab")[0].should == "baaabaaab"
+      /b(.+)??b/.match("baaabaaab")[0].should == "baaabaaab"
+      RUBY
+    end
+  end
 end
diff --git a/spec/ruby/language/regexp/subexpression_call_spec.rb b/spec/ruby/language/regexp/subexpression_call_spec.rb
new file mode 100644
index 0000000000..16b64cb327
--- /dev/null
+++ b/spec/ruby/language/regexp/subexpression_call_spec.rb
@@ -0,0 +1,50 @@
+require_relative '../../spec_helper'
+require_relative '../fixtures/classes'
+
+describe "Regexps with subexpression calls" do
+  it "allows numeric subexpression calls" do
+    /(a)\g<1>/.match("aa").to_a.should == [ "aa", "a" ]
+  end
+
+  it "treats subexpression calls as distinct from simple back-references" do
+    # Back-references only match a string which is equal to the original captured string.
+    /(?<three_digits>[0-9]{3})-\k<three_digits>/.match("123-123")[0].should == "123-123"
+    /(?<three_digits>[0-9]{3})-\k<three_digits>/.match("123-456").should == nil
+    # However, subexpression calls reuse the previous expression and can match a different
+    # string.
+    /(?<three_digits>[0-9]{3})-\g<three_digits>/.match("123-456")[0].should == "123-456"
+  end
+
+  it "allows recursive subexpression calls" do
+    # This pattern matches well-nested parenthesized expression.
+    parens = /^ (?<parens>  (?: \( \g<parens> \) | [^()] )*  ) $/x
+    parens.match("((a)(b))c(d)")[0].should == "((a)(b))c(d)"
+    parens.match("((a)(b)c(d)").should == nil
+  end
+
+  it "allows access to back-references from the current level" do
+    # Using \\k<first_char-0> accesses the last value captured in first_char
+    # on the current stack level.
+    mirror = /^ (?<mirror> (?: (?<first_char>.) \g<mirror> \k<first_char-0> )? ) $/x
+    mirror.match("abccba")[0].should == "abccba"
+    mirror.match("abccbd").should == nil
+
+    # OTOH, using \\k<first_char> accesses the last value captured in first_char,
+    # regardless of the stack level. Therefore, it can't be used to implement
+    # the mirror language.
+    broken_mirror = /^ (?<mirror> (?: (?<first_char>.) \g<mirror> \k<first_char> )? ) $/x
+    broken_mirror.match("abccba").should == nil
+    # This matches because the 'c' is captured in first_char and that value is
+    # then used for all subsequent back-references, regardless of nesting.
+    broken_mirror.match("abcccc")[0].should == "abcccc"
+  end
+
+  it "allows + and - in group names and referential constructs that don't use levels, i.e. subexpression calls" do
+    /(?<a+>a)\g<a+>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(?<a+b>a)\g<a+b>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(?<a+1>a)\g<a+1>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(?<a->a)\g<a->/.match("aa").to_a.should == [ "aa", "a" ]
+    /(?<a-b>a)\g<a-b>/.match("aa").to_a.should == [ "aa", "a" ]
+    /(?<a-1>a)\g<a-1>/.match("aa").to_a.should == [ "aa", "a" ]
+  end
+end
diff --git a/spec/ruby/language/singleton_class_spec.rb b/spec/ruby/language/singleton_class_spec.rb
index 91ce9726d5..7e9370d6f9 100644
--- a/spec/ruby/language/singleton_class_spec.rb
+++ b/spec/ruby/language/singleton_class_spec.rb
@@ -74,7 +74,7 @@ describe "A singleton class" do
   end
 
   it "doesn't have singleton class" do
-    -> { bignum_value.singleton_class.superclass.should == Integer }.should raise_error(TypeError)
+    -> { bignum_value.singleton_class }.should raise_error(TypeError)
   end
 end
 
diff --git a/spec/ruby/library/bigdecimal/BigDecimal_spec.rb b/spec/ruby/library/bigdecimal/BigDecimal_spec.rb
index b265e84798..d56c0a664b 100644
--- a/spec/ruby/library/bigdecimal/BigDecimal_spec.rb
+++ b/spec/ruby/library/bigdecimal/BigDecimal_spec.rb
@@ -30,15 +30,17 @@ describe "Kernel#BigDecimal" do
     BigDecimal(rational, 100).to_s.should == "0.99999999999999999999e18"
   end
 
-  ruby_version_is ""..."3.0" do
-    it "accepts significant digits >= given precision" do
+  it "accepts significant digits >= given precision" do
+    suppress_warning do
       BigDecimal("3.1415923", 10).precs[1].should >= 10
     end
+  end
 
-    it "determines precision from initial value" do
-      pi_string = "3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196442881097566593014782083152134043"
-      BigDecimal(pi_string).precs[1].should >= pi_string.size-1
-    end
+  it "determines precision from initial value" do
+    pi_string = "3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196442881097566593014782083152134043"
+    suppress_warning {
+      BigDecimal(pi_string).precs[1]
+    }.should >= pi_string.size-1
   end
 
   it "ignores leading and trailing whitespace" do
@@ -225,14 +227,12 @@ describe "Kernel#BigDecimal" do
       Float(@b).to_s.should == "166.66666666666666"
     end
 
-    ruby_version_is ""..."3.0" do
-      it "has the expected precision on the LHS" do
-        @a.precs[0].should == 18
-      end
+    it "has the expected precision on the LHS" do
+      suppress_warning { @a.precs[0] }.should == 18
+    end
 
-      it "has the expected maximum precision on the LHS" do
-        @a.precs[1].should == 27
-      end
+    it "has the expected maximum precision on the LHS" do
+      suppress_warning { @a.precs[1] }.should == 27
     end
 
     it "produces the expected result when done via Float" do
@@ -245,36 +245,32 @@ describe "Kernel#BigDecimal" do
 
     # Check underlying methods work as we understand
 
-    ruby_version_is ""..."3.0" do
-      it "BigDecimal precision is the number of digits rounded up to a multiple of nine" do
-        1.upto(100) do |n|
-          b = BigDecimal('4' * n)
-          precs, _ = b.precs
-          (precs >= 9).should be_true
-          (precs >= n).should be_true
-          (precs % 9).should == 0
-        end
-        BigDecimal('NaN').precs[0].should == 9
+    it "BigDecimal precision is the number of digits rounded up to a multiple of nine" do
+      1.upto(100) do |n|
+        b = BigDecimal('4' * n)
+        precs, _ = suppress_warning { b.precs }
+        (precs >= 9).should be_true
+        (precs >= n).should be_true
+        (precs % 9).should == 0
       end
+      suppress_warning { BigDecimal('NaN').precs[0] }.should == 9
+    end
 
-      it "BigDecimal maximum precision is nine more than precision except for abnormals" do
-        1.upto(100) do |n|
-          b = BigDecimal('4' * n)
-          precs, max = b.precs
-          max.should == precs + 9
-        end
-        BigDecimal('NaN').precs[1].should == 9
+    it "BigDecimal maximum precision is nine more than precision except for abnormals" do
+      1.upto(100) do |n|
+        b = BigDecimal('4' * n)
+        precs, max = suppress_warning { b.precs }
+        max.should == precs + 9
       end
+      suppress_warning { BigDecimal('NaN').precs[1] }.should == 9
     end
 
     it "BigDecimal(Rational, 18) produces the result we expect" do
       BigDecimal(@b, 18).to_s.should == "0.166666666666666667e3"
     end
 
-    ruby_version_is ""..."3.0" do
-      it "BigDecimal(Rational, BigDecimal.precs[0]) produces the result we expect" do
-        BigDecimal(@b, @a.precs[0]).to_s.should == "0.166666666666666667e3"
-      end
+    it "BigDecimal(Rational, BigDecimal.precs[0]) produces the result we expect" do
+      BigDecimal(@b, suppress_warning { @a.precs[0] }).to_s.should == "0.166666666666666667e3"
     end
 
     # Check the top-level expression works as we expect
diff --git a/spec/ruby/library/bigdecimal/add_spec.rb b/spec/ruby/library/bigdecimal/add_spec.rb
index f844ca96fa..bea8b8f764 100644
--- a/spec/ruby/library/bigdecimal/add_spec.rb
+++ b/spec/ruby/library/bigdecimal/add_spec.rb
@@ -41,14 +41,14 @@ describe "BigDecimal#add" do
     @frac_3.add(@frac_4, 6).should == BigDecimal("0.11111E16")
   end
 
-  it "returns a + [Integer value] with given precision" do
+  it "returns a + [Fixnum value] with given precision" do
     (1..10).each {|precision|
       @dot_ones.add(0, precision).should == BigDecimal("0." + "1" * precision)
     }
     BigDecimal("0.88").add(0, 1).should == BigDecimal("0.9")
   end
 
-  it "returns a + [Integer value] with given precision" do
+  it "returns a + [Bignum value] with given precision" do
     bignum = 10000000000000000000
     (1..20).each {|precision|
       @dot_ones.add(bignum, precision).should == BigDecimal("0.1E20")
diff --git a/spec/ruby/library/bigdecimal/precs_spec.rb b/spec/ruby/library/bigdecimal/precs_spec.rb
index 8809d094ef..5fda8d3087 100644
--- a/spec/ruby/library/bigdecimal/precs_spec.rb
+++ b/spec/ruby/library/bigdecimal/precs_spec.rb
@@ -1,44 +1,49 @@
 require_relative '../../spec_helper'
 require 'bigdecimal'
 
-ruby_version_is ""..."3.0" do
-  describe "BigDecimal#precs" do
+describe "BigDecimal#precs" do
+  before :each do
+    @infinity = BigDecimal("Infinity")
+    @infinity_neg = BigDecimal("-Infinity")
+    @nan = BigDecimal("NaN")
+    @zero = BigDecimal("0")
+    @zero_neg = BigDecimal("-0")
 
-    before :each do
-      @infinity = BigDecimal("Infinity")
-      @infinity_neg = BigDecimal("-Infinity")
-      @nan = BigDecimal("NaN")
-      @zero = BigDecimal("0")
-      @zero_neg = BigDecimal("-0")
-
-      @arr = [BigDecimal("2E40001"), BigDecimal("3E-20001"),\
-              @infinity, @infinity_neg, @nan, @zero, @zero_neg]
-      @precision = BigDecimal::BASE.to_s.length - 1
-    end
+    @arr = [BigDecimal("2E40001"), BigDecimal("3E-20001"),\
+            @infinity, @infinity_neg, @nan, @zero, @zero_neg]
+    @precision = BigDecimal::BASE.to_s.length - 1
+  end
 
-    it "returns array of two values" do
+  it "returns array of two values" do
+    suppress_warning do
       @arr.each do |x|
         x.precs.kind_of?(Array).should == true
         x.precs.size.should == 2
       end
     end
+  end
 
-    it "returns Integers as array values" do
+  it "returns Integers as array values" do
+    suppress_warning do
       @arr.each do |x|
         x.precs[0].kind_of?(Integer).should == true
         x.precs[1].kind_of?(Integer).should == true
       end
     end
+  end
 
-    it "returns the current value of significant digits as the first value" do
+  it "returns the current value of significant digits as the first value" do
+    suppress_warning do
       BigDecimal("3.14159").precs[0].should >= 6
       BigDecimal('1').precs[0].should == BigDecimal('1' + '0' * 100).precs[0]
       [@infinity, @infinity_neg, @nan, @zero, @zero_neg].each do |value|
         value.precs[0].should <= @precision
       end
     end
+  end
 
-    it "returns the maximum number of significant digits as the second value" do
+  it "returns the maximum number of significant digits as the second value" do
+    suppress_warning do
       BigDecimal("3.14159").precs[1].should >= 6
       BigDecimal('1').precs[1].should >= 1
       BigDecimal('1' + '0' * 100).precs[1].should >= 101
diff --git a/spec/ruby/library/bigdecimal/shared/to_int.rb b/spec/ruby/library/bigdecimal/shared/to_int.rb
index 41dd200b9f..0f16251612 100644
--- a/spec/ruby/library/bigdecimal/shared/to_int.rb
+++ b/spec/ruby/library/bigdecimal/shared/to_int.rb
@@ -6,7 +6,7 @@ describe :bigdecimal_to_int , shared: true do
     -> { BigDecimal("NaN").send(@method) }.should raise_error(FloatDomainError)
   end
 
-  it "returns Integer or Integer otherwise" do
+  it "returns Integer otherwise" do
     BigDecimal("3E-20001").send(@method).should == 0
     BigDecimal("2E4000").send(@method).should == 2 * 10 ** 4000
     BigDecimal("2").send(@method).should == 2
diff --git a/spec/ruby/library/matrix/divide_spec.rb b/spec/ruby/library/matrix/divide_spec.rb
index 84cecff582..2e3bb85bf6 100644
--- a/spec/ruby/library/matrix/divide_spec.rb
+++ b/spec/ruby/library/matrix/divide_spec.rb
@@ -16,11 +16,11 @@ describe "Matrix#/" do
 
   # Guard against the Mathn library
   guard -> { !defined?(Math.rsqrt) } do
-    it "returns the result of dividing self by an Integer" do
+    it "returns the result of dividing self by a Fixnum" do
       (@a / 2).should == Matrix[ [0, 1], [1, 2] ]
     end
 
-    it "returns the result of dividing self by an Integer" do
+    it "returns the result of dividing self by a Bignum" do
       (@a / bignum_value).should == Matrix[ [0, 0], [0, 0] ]
     end
   end
diff --git a/spec/ruby/library/matrix/multiply_spec.rb b/spec/ruby/library/matrix/multiply_spec.rb
index e488bb0f5d..585f268931 100644
--- a/spec/ruby/library/matrix/multiply_spec.rb
+++ b/spec/ruby/library/matrix/multiply_spec.rb
@@ -16,11 +16,11 @@ describe "Matrix#*" do
     (@a * Vector[1,2]).should == Vector[5, 11]
   end
 
-  it "returns the result of multiplying the elements of self and an Integer" do
+  it "returns the result of multiplying the elements of self and a Fixnum" do
     (@a * 2).should == Matrix[ [2, 4], [6, 8] ]
   end
 
-  it "returns the result of multiplying the elements of self and an Integer" do
+  it "returns the result of multiplying the elements of self and a Bignum" do
     (@a * bignum_value).should == Matrix[
       [9223372036854775808, 18446744073709551616],
       [27670116110564327424, 36893488147419103232]
diff --git a/spec/ruby/library/pathname/divide_spec.rb b/spec/ruby/library/pathname/divide_spec.rb
new file mode 100644
index 0000000000..8af79d0c8f
--- /dev/null
+++ b/spec/ruby/library/pathname/divide_spec.rb
@@ -0,0 +1,6 @@
+require_relative '../../spec_helper'
+require_relative 'shared/plus'
+
+describe "Pathname#/" do
+  it_behaves_like :pathname_plus, :/
+end
diff --git a/spec/ruby/library/pathname/plus_spec.rb b/spec/ruby/library/pathname/plus_spec.rb
new file mode 100644
index 0000000000..57e472c266
--- /dev/null
+++ b/spec/ruby/library/pathname/plus_spec.rb
@@ -0,0 +1,6 @@
+require_relative '../../spec_helper'
+require_relative 'shared/plus'
+
+describe "Pathname#+" do
+  it_behaves_like :pathname_plus, :+
+end
diff --git a/spec/ruby/library/pathname/shared/plus.rb b/spec/ruby/library/pathname/shared/plus.rb
new file mode 100644
index 0000000000..b3b896ea43
--- /dev/null
+++ b/spec/ruby/library/pathname/shared/plus.rb
@@ -0,0 +1,8 @@
+require 'pathname'
+
+describe :pathname_plus, shared: true do
+  it "appends a pathname to self" do
+    p = Pathname.new("/usr")
+    p.send(@method, "bin/ruby").should == Pathname.new("/usr/bin/ruby")
+  end
+end
diff --git a/spec/ruby/library/stringio/bytes_spec.rb b/spec/ruby/library/stringio/bytes_spec.rb
index 1c0607db6e..4ef7a490a5 100644
--- a/spec/ruby/library/stringio/bytes_spec.rb
+++ b/spec/ruby/library/stringio/bytes_spec.rb
@@ -4,10 +4,26 @@ require_relative 'shared/each_byte'
 
 ruby_version_is ''...'3.0' do
   describe "StringIO#bytes" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_byte, :bytes
   end
 
   describe "StringIO#bytes when self is not readable" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_byte_not_readable, :bytes
   end
 end
diff --git a/spec/ruby/library/stringio/chars_spec.rb b/spec/ruby/library/stringio/chars_spec.rb
index 3383dcfc57..58cba77634 100644
--- a/spec/ruby/library/stringio/chars_spec.rb
+++ b/spec/ruby/library/stringio/chars_spec.rb
@@ -4,10 +4,26 @@ require_relative 'shared/each_char'
 
 ruby_version_is ''...'3.0' do
   describe "StringIO#chars" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_char, :chars
   end
 
   describe "StringIO#chars when self is not readable" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_char_not_readable, :chars
   end
 end
diff --git a/spec/ruby/library/stringio/codepoints_spec.rb b/spec/ruby/library/stringio/codepoints_spec.rb
index 0dfaac2a29..ceaadefc32 100644
--- a/spec/ruby/library/stringio/codepoints_spec.rb
+++ b/spec/ruby/library/stringio/codepoints_spec.rb
@@ -4,9 +4,16 @@ require_relative 'fixtures/classes'
 require_relative 'shared/codepoints'
 
 ruby_version_is ''...'3.0' do
-
   # See redmine #1667
   describe "StringIO#codepoints" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_codepoints, :codepoints
   end
 end
diff --git a/spec/ruby/library/stringio/lines_spec.rb b/spec/ruby/library/stringio/lines_spec.rb
index 4a2aeac37e..42d11772ae 100644
--- a/spec/ruby/library/stringio/lines_spec.rb
+++ b/spec/ruby/library/stringio/lines_spec.rb
@@ -4,18 +4,50 @@ require_relative 'shared/each'
 
 ruby_version_is ''...'3.0' do
   describe "StringIO#lines when passed a separator" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_separator, :lines
   end
 
   describe "StringIO#lines when passed no arguments" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_no_arguments, :lines
   end
 
   describe "StringIO#lines when self is not readable" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_not_readable, :lines
   end
 
   describe "StringIO#lines when passed chomp" do
+    before :each do
+      @verbose, $VERBOSE = $VERBOSE, nil
+    end
+
+    after :each do
+      $VERBOSE = @verbose
+    end
+
     it_behaves_like :stringio_each_chomp, :lines
   end
 end
diff --git a/spec/ruby/library/stringscanner/shared/peek.rb b/spec/ruby/library/stringscanner/shared/peek.rb
index 768f5f2d58..4e2e643353 100644
--- a/spec/ruby/library/stringscanner/shared/peek.rb
+++ b/spec/ruby/library/stringscanner/shared/peek.rb
@@ -22,7 +22,7 @@ describe :strscan_peek, shared: true do
     -> { @s.send(@method, -2) }.should raise_error(ArgumentError)
   end
 
-  it "raises a RangeError when the passed argument is an Integer" do
+  it "raises a RangeError when the passed argument is a Bignum" do
     -> { @s.send(@method, bignum_value) }.should raise_error(RangeError)
   end
 
diff --git a/spec/ruby/optional/capi/bignum_spec.rb b/spec/ruby/optional/capi/bignum_spec.rb
index b20275b8f7..cde929af28 100644
--- a/spec/ruby/optional/capi/bignum_spec.rb
+++ b/spec/ruby/optional/capi/bignum_spec.rb
@@ -187,14 +187,14 @@ describe "CApiBignumSpecs" do
     it "returns a Fixnum for a Fixnum input value" do
       val = @s.rb_dbl2big(2)
 
-      val.kind_of?(Fixnum).should == true
+      val.kind_of?(Integer).should == true
       val.should == 2
     end
 
     it "returns a Fixnum for a Float input value" do
       val = @s.rb_dbl2big(2.5)
 
-      val.kind_of?(Fixnum).should == true
+      val.kind_of?(Integer).should == true
       val.should == 2
     end
 
@@ -202,7 +202,7 @@ describe "CApiBignumSpecs" do
       input = 219238102380912830988.5 # chosen by fair dice roll
       val   = @s.rb_dbl2big(input)
 
-      val.kind_of?(Bignum).should == true
+      val.kind_of?(Integer).should == true
 
       # This value is based on the output of a simple C extension that uses
       # rb_dbl2big() to convert the above input value to a Bignum.
diff --git a/spec/ruby/optional/capi/binding_spec.rb b/spec/ruby/optional/capi/binding_spec.rb
new file mode 100644
index 0000000000..966d650c46
--- /dev/null
+++ b/spec/ruby/optional/capi/binding_spec.rb
@@ -0,0 +1,19 @@
+require_relative 'spec_helper'
+
+load_extension("binding")
+
+describe "CApiBindingSpecs" do
+  before :each do
+    @b = CApiBindingSpecs.new
+  end
+
+  describe "Kernel#binding" do
+    it "gives the top-most Ruby binding when called from C" do
+      foo = 14
+      b = @b.get_binding
+      b.local_variable_get(:foo).should == 14
+      b.local_variable_set :foo, 12
+      foo.should == 12
+    end
+  end
+end
diff --git a/spec/ruby/optional/capi/ext/binding_spec.c b/spec/ruby/optional/capi/ext/binding_spec.c
new file mode 100644
index 0000000000..b2e3c88b6d
--- /dev/null
+++ b/spec/ruby/optional/capi/ext/binding_spec.c
@@ -0,0 +1,19 @@
+#include "ruby.h"
+#include "rubyspec.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static VALUE binding_spec_get_binding(VALUE self) {
+  return rb_funcall(self, rb_intern("binding"), 0);
+}
+
+void Init_binding_spec(void) {
+  VALUE cls = rb_define_class("CApiBindingSpecs", rb_cObject);
+  rb_define_method(cls, "get_binding", binding_spec_get_binding, 0);
+}
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/spec/ruby/optional/capi/hash_spec.rb b/spec/ruby/optional/capi/hash_spec.rb
index 75f1978585..a60467a66b 100644
--- a/spec/ruby/optional/capi/hash_spec.rb
+++ b/spec/ruby/optional/capi/hash_spec.rb
@@ -21,7 +21,7 @@ describe "C-API Hash function" do
 
       # The actual conversion is an implementation detail.
       # We only care that ultimately we get a Fixnum instance.
-      @s.rb_hash(obj).should be_an_instance_of(Fixnum)
+      @s.rb_hash(obj).should.between?(fixnum_min, fixnum_max)
     end
 
     it "calls #to_int to converts a value returned by #hash to a Fixnum" do
diff --git a/spec/ruby/optional/capi/numeric_spec.rb b/spec/ruby/optional/capi/numeric_spec.rb
index d433d19274..95213d3f2b 100644
--- a/spec/ruby/optional/capi/numeric_spec.rb
+++ b/spec/ruby/optional/capi/numeric_spec.rb
@@ -264,52 +264,45 @@ describe "CApiNumericSpecs" do
   describe "rb_Integer" do
     it "creates an Integer from a String" do
       i = @s.rb_Integer("8675309")
-      i.should be_kind_of(Integer)
-      i.should eql(8675309)
+      i.should == 8675309
     end
   end
 
   describe "rb_ll2inum" do
     it "creates a Fixnum from a small signed long long" do
       i = @s.rb_ll2inum_14()
-      i.should be_kind_of(Fixnum)
-      i.should eql(14)
+      i.should == 14
     end
   end
 
   describe "rb_ull2inum" do
     it "creates a Fixnum from a small unsigned long long" do
       i = @s.rb_ull2inum_14()
-      i.should be_kind_of(Fixnum)
-      i.should eql(14)
+      i.should == 14
     end
 
     it "creates a positive Bignum from a negative long long" do
       i = @s.rb_ull2inum_n14()
-      i.should be_kind_of(Bignum)
-      i.should eql(2 ** (@s.size_of_long_long * 8) - 14)
+      i.should == (2 ** (@s.size_of_long_long * 8) - 14)
     end
   end
 
   describe "rb_int2inum" do
     it "creates a Fixnum from a long" do
       i = @s.rb_int2inum_14()
-      i.should be_kind_of(Fixnum)
-      i.should eql(14)
+      i.should == 14
     end
   end
 
   describe "rb_uint2inum" do
     it "creates a Fixnum from a long" do
       i = @s.rb_uint2inum_14()
-      i.should be_kind_of(Fixnum)
-      i.should eql(14)
+      i.should == 14
     end
 
     it "creates a positive Bignum from a negative long" do
       i = @s.rb_uint2inum_n14()
-      i.should be_kind_of(Bignum)
-      i.should eql(2 ** (@s.size_of_VALUE * 8) - 14)
+      i.should == (2 ** (@s.size_of_VALUE * 8) - 14)
     end
   end
 
diff --git a/spec/ruby/optional/capi/object_spec.rb b/spec/ruby/optional/capi/object_spec.rb
index e8e905b237..be149898bd 100644
--- a/spec/ruby/optional/capi/object_spec.rb
+++ b/spec/ruby/optional/capi/object_spec.rb
@@ -448,7 +448,7 @@ describe "CApiObject" do
   describe "rb_class_of" do
     it "returns the class of an object" do
       @o.rb_class_of(nil).should == NilClass
-      @o.rb_class_of(0).should == Fixnum
+      @o.rb_class_of(0).should == Integer
       @o.rb_class_of(0.1).should == Float
       @o.rb_class_of(ObjectTest.new).should == ObjectTest
     end
@@ -464,7 +464,7 @@ describe "CApiObject" do
   describe "rb_obj_classname" do
     it "returns the class name of an object" do
       @o.rb_obj_classname(nil).should == 'NilClass'
-      @o.rb_obj_classname(0).should == Fixnum.to_s
+      @o.rb_obj_classname(0).should == 'Integer'
       @o.rb_obj_classname(0.1).should == 'Float'
       @o.rb_obj_classname(ObjectTest.new).should == 'ObjectTest'
     end
diff --git a/spec/ruby/optional/capi/util_spec.rb b/spec/ruby/optional/capi/util_spec.rb
index 0251c7c62b..a90c28a78e 100644
--- a/spec/ruby/optional/capi/util_spec.rb
+++ b/spec/ruby/optional/capi/util_spec.rb
@@ -289,7 +289,7 @@ describe "C-API Util function" do
 
   describe "rb_sourceline" do
     it "returns the current ruby file" do
-      @o.rb_sourceline.should be_kind_of(Fixnum)
+      @o.rb_sourceline.should be_kind_of(Integer)
     end
   end
 
diff --git a/spec/ruby/security/cve_2020_10663_spec.rb b/spec/ruby/security/cve_2020_10663_spec.rb
index 634afda525..b97323af08 100644
--- a/spec/ruby/security/cve_2020_10663_spec.rb
+++ b/spec/ruby/security/cve_2020_10663_spec.rb
@@ -23,19 +23,21 @@ guard -> {
   JSON.const_defined?(:Pure) or
   version_is(JSON::VERSION, '2.3.0')
 } do
-  describe "CVE-2020-10663 is resisted by" do
-    it "only creating custom objects if passed create_additions: true or using JSON.load" do
-      obj = JSONSpecs::MyClass.new("bar")
-      JSONSpecs::MyClass.should.json_creatable?
-      json = JSON.dump(obj)
+  platform_is_not :darwin do
+    describe "CVE-2020-10663 is resisted by" do
+      it "only creating custom objects if passed create_additions: true or using JSON.load" do
+        obj = JSONSpecs::MyClass.new("bar")
+        JSONSpecs::MyClass.should.json_creatable?
+        json = JSON.dump(obj)
 
-      JSON.parse(json, create_additions: true).class.should == JSONSpecs::MyClass
-      JSON(json, create_additions: true).class.should == JSONSpecs::MyClass
-      JSON.load(json).class.should == JSONSpecs::MyClass
+        JSON.parse(json, create_additions: true).class.should == JSONSpecs::MyClass
+        JSON(json, create_additions: true).class.should == JSONSpecs::MyClass
+        JSON.load(json).class.should == JSONSpecs::MyClass
 
-      JSON.parse(json).class.should == Hash
-      JSON.parse(json, nil).class.should == Hash
-      JSON(json).class.should == Hash
+        JSON.parse(json).class.should == Hash
+        JSON.parse(json, nil).class.should == Hash
+        JSON(json).class.should == Hash
+      end
     end
   end
 end
diff --git a/spec/ruby/shared/kernel/object_id.rb b/spec/ruby/shared/kernel/object_id.rb
index 175f3fb749..7acdb27554 100644
--- a/spec/ruby/shared/kernel/object_id.rb
+++ b/spec/ruby/shared/kernel/object_id.rb
@@ -16,7 +16,7 @@ describe :object_id, shared: true do
     o1.__send__(@method).should_not == o2.__send__(@method)
   end
 
-  it "returns the same value for two Integers with the same value" do
+  it "returns the same value for two Fixnums with the same value" do
     o1 = 1
     o2 = 1
     o1.send(@method).should == o2.send(@method)
@@ -46,7 +46,7 @@ describe :object_id, shared: true do
     o1.send(@method).should == o2.send(@method)
   end
 
-  it "returns a different value for two Integer literals" do
+  it "returns a different value for two Bignum literals" do
     o1 = 2e100.to_i
     o2 = 2e100.to_i
     o1.send(@method).should_not == o2.send(@method)
@@ -64,14 +64,14 @@ describe :object_id, shared: true do
     o1.send(@method).should_not == o2.send(@method)
   end
 
-  it "returns a different value for two numbers near the 32 bit Integer limit" do
+  it "returns a different value for two numbers near the 32 bit Fixnum limit" do
     o1 = -1
     o2 = 2 ** 30 - 1
 
     o1.send(@method).should_not == o2.send(@method)
   end
 
-  it "returns a different value for two numbers near the 64 bit Integer limit" do
+  it "returns a different value for two numbers near the 64 bit Fixnum limit" do
     o1 = -1
     o2 = 2 ** 62 - 1
 
diff --git a/spec/ruby/shared/rational/exponent.rb b/spec/ruby/shared/rational/exponent.rb
index 0f6abcd634..4ef83ee806 100644
--- a/spec/ruby/shared/rational/exponent.rb
+++ b/spec/ruby/shared/rational/exponent.rb
@@ -59,7 +59,7 @@ describe :rational_exponent, shared: true do
     end
   end
 
-  describe "when passed Integer" do
+  describe "when passed Bignum" do
     # #5713
     it "returns Rational(0) when self is Rational(0) and the exponent is positive" do
       (Rational(0) ** bignum_value).should eql(Rational(0))
@@ -85,13 +85,21 @@ describe :rational_exponent, shared: true do
     end
 
     it "returns positive Infinity when self is > 1" do
-      (Rational(2) ** bignum_value).infinite?.should == 1
-      (Rational(fixnum_max) ** bignum_value).infinite?.should == 1
+      -> {
+        (Rational(2) ** bignum_value).infinite?.should == 1
+      }.should complain(/warning: in a\*\*b, b may be too big/)
+      -> {
+        (Rational(fixnum_max) ** bignum_value).infinite?.should == 1
+      }.should complain(/warning: in a\*\*b, b may be too big/)
     end
 
     it "returns 0.0 when self is > 1 and the exponent is negative" do
-      (Rational(2) ** -bignum_value).should eql(0.0)
-      (Rational(fixnum_max) ** -bignum_value).should eql(0.0)
+      -> {
+        (Rational(2) ** -bignum_value).should eql(0.0)
+      }.should complain(/warning: in a\*\*b, b may be too big/)
+      -> {
+        (Rational(fixnum_max) ** -bignum_value).should eql(0.0)
+      }.should complain(/warning: in a\*\*b, b may be too big/)
     end
 
     # Fails on linux due to pow() bugs in glibc: http://sources.redhat.com/bugzilla/show_bug.cgi?id=3866
diff --git a/spec/ruby/shared/string/times.rb b/spec/ruby/shared/string/times.rb
index fcc9d00fd6..cd4edf5340 100644
--- a/spec/ruby/shared/string/times.rb
+++ b/spec/ruby/shared/string/times.rb
@@ -23,7 +23,7 @@ describe :string_times, shared: true do
     -> { @object.call("cool", min_long) }.should raise_error(ArgumentError)
   end
 
-  it "raises a RangeError when given integer is an Integer" do
+  it "raises a RangeError when given integer is a Bignum" do
     -> { @object.call("cool", 999999999999999999999) }.should raise_error(RangeError)
     -> { @object.call("", 999999999999999999999) }.should raise_error(RangeError)
   end