Update to ruby/spec@3fc4444

14 files changed, 1027 insertions, 117 deletions

diff --git a/spec/ruby/language/assignments_spec.rb b/spec/ruby/language/assignments_spec.rb
new file mode 100644
index 0000000000..005c1f0dc3
--- /dev/null
+++ b/spec/ruby/language/assignments_spec.rb
@@ -0,0 +1,150 @@
+require_relative '../spec_helper'
+
+# Should be synchronized with spec/ruby/language/optional_assignments_spec.rb
+describe 'Assignments' do
+  describe 'using +=' do
+    describe 'using an accessor' do
+      before do
+        klass = Class.new { attr_accessor :b }
+        @a    = klass.new
+      end
+
+      it 'does evaluate receiver only once when assigns' do
+        ScratchPad.record []
+        @a.b = 1
+
+        (ScratchPad << :evaluated; @a).b += 2
+
+        ScratchPad.recorded.should == [:evaluated]
+        @a.b.should == 3
+      end
+
+      it 'ignores method visibility when receiver is self' do
+        klass_with_private_methods = Class.new do
+          def initialize(n) @a = n end
+          def public_method(n); self.a += n end
+          private
+          def a; @a end
+          def a=(n) @a = n; 42 end
+        end
+
+        a = klass_with_private_methods.new(0)
+        a.public_method(2).should == 2
+      end
+    end
+
+    describe 'using a #[]' do
+      before do
+        klass = Class.new do
+          def [](k)
+            @hash ||= {}
+            @hash[k]
+          end
+
+          def []=(k, v)
+            @hash ||= {}
+            @hash[k] = v
+            7
+          end
+        end
+        @b = klass.new
+      end
+
+      it 'evaluates receiver only once when assigns' do
+        ScratchPad.record []
+        a = {k: 1}
+
+        (ScratchPad << :evaluated; a)[:k] += 2
+
+        ScratchPad.recorded.should == [:evaluated]
+        a[:k].should == 3
+      end
+
+      it 'ignores method visibility when receiver is self' do
+        klass_with_private_methods = Class.new do
+          def initialize(h) @a = h end
+          def public_method(k, n); self[k] += n end
+          private
+          def [](k) @a[k] end
+          def []=(k, v) @a[k] = v; 42 end
+        end
+
+        a = klass_with_private_methods.new(k: 0)
+        a.public_method(:k, 2).should == 2
+      end
+
+      context 'splatted argument' do
+        it 'correctly handles it' do
+          @b[:m] = 10
+          (@b[*[:m]] += 10).should == 20
+          @b[:m].should == 20
+
+          @b[:n] = 10
+          (@b[*(1; [:n])] += 10).should == 20
+          @b[:n].should == 20
+
+          @b[:k] = 10
+          (@b[*begin 1; [:k] end] += 10).should == 20
+          @b[:k].should == 20
+        end
+
+        it 'calls #to_a only once' do
+          k = Object.new
+          def k.to_a
+            ScratchPad << :to_a
+            [:k]
+          end
+
+          ScratchPad.record []
+          @b[:k] = 10
+          (@b[*k] += 10).should == 20
+          @b[:k].should == 20
+          ScratchPad.recorded.should == [:to_a]
+        end
+
+        it 'correctly handles a nested splatted argument' do
+          @b[:k] = 10
+          (@b[*[*[:k]]] += 10).should == 20
+          @b[:k].should == 20
+        end
+
+        it 'correctly handles multiple nested splatted arguments' do
+          klass_with_multiple_parameters = Class.new do
+            def [](k1, k2, k3)
+              @hash ||= {}
+              @hash[:"#{k1}#{k2}#{k3}"]
+            end
+
+            def []=(k1, k2, k3, v)
+              @hash ||= {}
+              @hash[:"#{k1}#{k2}#{k3}"] = v
+              7
+            end
+          end
+          a = klass_with_multiple_parameters.new
+
+          a[:a, :b, :c] = 10
+          (a[*[:a], *[:b], *[:c]] += 10).should == 20
+          a[:a, :b, :c].should == 20
+        end
+      end
+    end
+
+    describe 'using compounded constants' do
+      it 'causes side-effects of the module part to be applied only once (when assigns)' do
+        module ConstantSpecs
+          OpAssignTrue = 1
+        end
+
+        suppress_warning do # already initialized constant
+          x = 0
+          (x += 1; ConstantSpecs)::OpAssignTrue += 2
+          x.should == 1
+          ConstantSpecs::OpAssignTrue.should == 3
+        end
+
+        ConstantSpecs.send :remove_const, :OpAssignTrue
+      end
+    end
+  end
+end
diff --git a/spec/ruby/language/block_spec.rb b/spec/ruby/language/block_spec.rb
index 90329e2f6f..578d9cb3b0 100644
--- a/spec/ruby/language/block_spec.rb
+++ b/spec/ruby/language/block_spec.rb
@@ -40,10 +40,42 @@ describe "A block yielded a single" do
       m([1, 2]) { |a=5, b, c, d| [a, b, c, d] }.should == [5, 1, 2, nil]
     end
 
+    it "assigns elements to pre arguments" do
+      m([1, 2]) { |a, b, c, d=5| [a, b, c, d] }.should == [1, 2, nil, 5]
+    end
+
+    it "assigns elements to pre and post arguments" do
+      m([1               ]) { |a, b=5, c=6, d, e| [a, b, c, d, e] }.should == [1, 5, 6, nil, nil]
+      m([1, 2            ]) { |a, b=5, c=6, d, e| [a, b, c, d, e] }.should == [1, 5, 6, 2, nil]
+      m([1, 2, 3         ]) { |a, b=5, c=6, d, e| [a, b, c, d, e] }.should == [1, 5, 6, 2, 3]
+      m([1, 2, 3, 4      ]) { |a, b=5, c=6, d, e| [a, b, c, d, e] }.should == [1, 2, 6, 3, 4]
+      m([1, 2, 3, 4, 5   ]) { |a, b=5, c=6, d, e| [a, b, c, d, e] }.should == [1, 2, 3, 4, 5]
+      m([1, 2, 3, 4, 5, 6]) { |a, b=5, c=6, d, e| [a, b, c, d, e] }.should == [1, 2, 3, 4, 5]
+    end
+
+    it "assigns elements to pre and post arguments when *rest is present" do
+      m([1               ]) { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.should == [1, 5, 6, [], nil, nil]
+      m([1, 2            ]) { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.should == [1, 5, 6, [], 2, nil]
+      m([1, 2, 3         ]) { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.should == [1, 5, 6, [], 2, 3]
+      m([1, 2, 3, 4      ]) { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.should == [1, 2, 6, [], 3, 4]
+      m([1, 2, 3, 4, 5   ]) { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.should == [1, 2, 3, [], 4, 5]
+      m([1, 2, 3, 4, 5, 6]) { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.should == [1, 2, 3, [4], 5, 6]
+    end
+
     ruby_version_is "3.2" do
       it "does not autosplat single argument to required arguments when a keyword rest argument is present" do
         m([1, 2]) { |a, **k| [a, k] }.should == [[1, 2], {}]
       end
+
+      it "does not autosplat single argument to required arguments when keyword arguments are present" do
+        m([1, 2]) { |a, b: :b, c: :c| [a, b, c] }.should == [[1, 2], :b, :c]
+      end
+
+      it "raises error when required keyword arguments are present" do
+        -> {
+          m([1, 2]) { |a, b:, c:| [a, b, c] }
+        }.should raise_error(ArgumentError, "missing keywords: :b, :c")
+      end
     end
 
     ruby_version_is ''..."3.2" do
@@ -51,6 +83,16 @@ describe "A block yielded a single" do
       it "autosplats single argument to required arguments when a keyword rest argument is present" do
         m([1, 2]) { |a, **k| [a, k] }.should == [1, {}]
       end
+
+      it "autosplats single argument to required arguments when optional keyword arguments are present" do
+        m([1, 2]) { |a, b: :b, c: :c| [a, b, c] }.should == [1, :b, :c]
+      end
+
+      it "raises error when required keyword arguments are present" do
+        -> {
+          m([1, 2]) { |a, b:, c:| [a, b, c] }
+        }.should raise_error(ArgumentError, "missing keywords: :b, :c")
+      end
     end
 
     it "assigns elements to mixed argument types" do
@@ -368,7 +410,6 @@ describe "A block" do
 
       -> { @y.s(obj) { |a, b| } }.should raise_error(ZeroDivisionError)
     end
-
   end
 
   describe "taking |a, *b| arguments" do
@@ -701,6 +742,42 @@ describe "A block" do
       eval("Proc.new { |_,_| }").should be_an_instance_of(Proc)
     end
   end
+
+  describe 'pre and post parameters' do
+    it "assigns nil to unassigned required arguments" do
+      proc { |a, *b, c, d| [a, b, c, d] }.call(1, 2).should == [1, [], 2, nil]
+    end
+
+    it "assigns elements to optional arguments" do
+      proc { |a=5, b=4, c=3| [a, b, c] }.call(1, 2).should == [1, 2, 3]
+    end
+
+    it "assigns elements to post arguments" do
+      proc { |a=5, b, c, d| [a, b, c, d] }.call(1, 2).should == [5, 1, 2, nil]
+    end
+
+    it "assigns elements to pre arguments" do
+      proc { |a, b, c, d=5| [a, b, c, d] }.call(1, 2).should == [1, 2, nil, 5]
+    end
+
+    it "assigns elements to pre and post arguments" do
+      proc { |a, b=5, c=6, d, e| [a, b, c, d, e] }.call(1               ).should == [1, 5, 6, nil, nil]
+      proc { |a, b=5, c=6, d, e| [a, b, c, d, e] }.call(1, 2            ).should == [1, 5, 6, 2, nil]
+      proc { |a, b=5, c=6, d, e| [a, b, c, d, e] }.call(1, 2, 3         ).should == [1, 5, 6, 2, 3]
+      proc { |a, b=5, c=6, d, e| [a, b, c, d, e] }.call(1, 2, 3, 4      ).should == [1, 2, 6, 3, 4]
+      proc { |a, b=5, c=6, d, e| [a, b, c, d, e] }.call(1, 2, 3, 4, 5   ).should == [1, 2, 3, 4, 5]
+      proc { |a, b=5, c=6, d, e| [a, b, c, d, e] }.call(1, 2, 3, 4, 5, 6).should == [1, 2, 3, 4, 5]
+    end
+
+    it "assigns elements to pre and post arguments when *rest is present" do
+      proc { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.call(1               ).should == [1, 5, 6, [], nil, nil]
+      proc { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.call(1, 2            ).should == [1, 5, 6, [], 2, nil]
+      proc { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.call(1, 2, 3         ).should == [1, 5, 6, [], 2, 3]
+      proc { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.call(1, 2, 3, 4      ).should == [1, 2, 6, [], 3, 4]
+      proc { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.call(1, 2, 3, 4, 5   ).should == [1, 2, 3, [], 4, 5]
+      proc { |a, b=5, c=6, *d, e, f| [a, b, c, d, e, f] }.call(1, 2, 3, 4, 5, 6).should == [1, 2, 3, [4], 5, 6]
+    end
+  end
 end
 
 describe "Block-local variables" do
@@ -921,7 +998,7 @@ end
 
 describe "Anonymous block forwarding" do
   ruby_version_is "3.1" do
-    it "forwards blocks to other functions that formally declare anonymous blocks" do
+    it "forwards blocks to other method that formally declares anonymous block" do
       eval <<-EOF
           def b(&); c(&) end
           def c(&); yield :non_null end
diff --git a/spec/ruby/language/case_spec.rb b/spec/ruby/language/case_spec.rb
index 1a3925c9c6..cfa612b93a 100644
--- a/spec/ruby/language/case_spec.rb
+++ b/spec/ruby/language/case_spec.rb
@@ -399,6 +399,22 @@ describe "The 'case'-construct" do
       :called
     end.should == :called
   end
+
+  it "supports declaring variables in the case target expression" do
+    def test(v)
+      case new_variable_in_expression = v
+      when true
+        # This extra block is a test that `new_variable_in_expression` is declared outside of it and not inside
+        self.then { new_variable_in_expression }
+      else
+        # Same
+        self.then { new_variable_in_expression.casecmp?("foo") }
+      end
+    end
+
+    self.test("bar").should == false
+    self.test(true).should == true
+  end
 end
 
 describe "The 'case'-construct with no target expression" do
diff --git a/spec/ruby/language/defined_spec.rb b/spec/ruby/language/defined_spec.rb
index b84fe9394a..34408c0190 100644
--- a/spec/ruby/language/defined_spec.rb
+++ b/spec/ruby/language/defined_spec.rb
@@ -116,6 +116,11 @@ describe "The defined? keyword when called with a method name" do
       defined?(obj.a_defined_method).should == "method"
     end
 
+    it "returns 'method' for []=" do
+      a = []
+      defined?(a[0] = 1).should == "method"
+    end
+
     it "returns nil if the method is not defined" do
       obj = DefinedSpecs::Basic.new
       defined?(obj.an_undefined_method).should be_nil
@@ -231,6 +236,14 @@ describe "The defined? keyword for an expression" do
     defined?(@@defined_specs_x = 2).should == "assignment"
   end
 
+  it "returns 'assignment' for assigning a constant" do
+    defined?(A = 2).should == "assignment"
+  end
+
+  it "returns 'assignment' for assigning a fully qualified constant" do
+    defined?(Object::A = 2).should == "assignment"
+  end
+
   it "returns 'assignment' for assigning multiple variables" do
     defined?((a, b = 1, 2)).should == "assignment"
   end
@@ -248,7 +261,27 @@ describe "The defined? keyword for an expression" do
   end
 
   it "returns 'assignment' for an expression with '+='" do
-    defined?(x += 2).should == "assignment"
+    defined?(a += 1).should == "assignment"
+    defined?(@a += 1).should == "assignment"
+    defined?(@@a += 1).should == "assignment"
+    defined?($a += 1).should == "assignment"
+    defined?(A += 1).should == "assignment"
+    # fully qualified constant check is moved out into a separate test case
+    defined?(a.b += 1).should == "assignment"
+    defined?(a[:b] += 1).should == "assignment"
+  end
+
+  # https://bugs.ruby-lang.org/issues/20111
+  ruby_version_is ""..."3.4" do
+    it "returns 'expression' for an assigning a fully qualified constant with '+='" do
+      defined?(Object::A += 1).should == "expression"
+    end
+  end
+
+  ruby_version_is "3.4" do
+    it "returns 'assignment' for an assigning a fully qualified constant with '+='" do
+      defined?(Object::A += 1).should == "assignment"
+    end
   end
 
   it "returns 'assignment' for an expression with '*='" do
@@ -279,12 +312,90 @@ describe "The defined? keyword for an expression" do
     defined?(x >>= 2).should == "assignment"
   end
 
-  it "returns 'assignment' for an expression with '||='" do
-    defined?(x ||= 2).should == "assignment"
+  context "||=" do
+    it "returns 'assignment' for assigning a local variable with '||='" do
+      defined?(a ||= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning an instance variable with '||='" do
+      defined?(@a ||= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a class variable with '||='" do
+      defined?(@@a ||= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a global variable with '||='" do
+      defined?($a ||= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a constant with '||='" do
+      defined?(A ||= true).should == "assignment"
+    end
+
+    # https://bugs.ruby-lang.org/issues/20111
+    ruby_version_is ""..."3.4" do
+      it "returns 'expression' for assigning a fully qualified constant with '||='" do
+        defined?(Object::A ||= true).should == "expression"
+      end
+    end
+
+    ruby_version_is "3.4" do
+      it "returns 'assignment' for assigning a fully qualified constant with '||='" do
+        defined?(Object::A ||= true).should == "assignment"
+      end
+    end
+
+    it "returns 'assignment' for assigning an attribute with '||='" do
+      defined?(a.b ||= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a referenced element with '||='" do
+      defined?(a[:b] ||= true).should == "assignment"
+    end
   end
 
-  it "returns 'assignment' for an expression with '&&='" do
-    defined?(x &&= 2).should == "assignment"
+  context "&&=" do
+    it "returns 'assignment' for assigning a local variable with '&&='" do
+      defined?(a &&= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning an instance variable with '&&='" do
+      defined?(@a &&= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a class variable with '&&='" do
+      defined?(@@a &&= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a global variable with '&&='" do
+      defined?($a &&= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a constant with '&&='" do
+      defined?(A &&= true).should == "assignment"
+    end
+
+    # https://bugs.ruby-lang.org/issues/20111
+    ruby_version_is ""..."3.4" do
+      it "returns 'expression' for assigning a fully qualified constant with '&&='" do
+        defined?(Object::A &&= true).should == "expression"
+      end
+    end
+
+    ruby_version_is "3.4" do
+      it "returns 'assignment' for assigning a fully qualified constant with '&&='" do
+        defined?(Object::A &&= true).should == "assignment"
+      end
+    end
+
+    it "returns 'assignment' for assigning an attribute with '&&='" do
+      defined?(a.b &&= true).should == "assignment"
+    end
+
+    it "returns 'assignment' for assigning a referenced element with '&&='" do
+      defined?(a[:b] &&= true).should == "assignment"
+    end
   end
 
   it "returns 'assignment' for an expression with '**='" do
diff --git a/spec/ruby/language/delegation_spec.rb b/spec/ruby/language/delegation_spec.rb
index 020787aff6..d780506421 100644
--- a/spec/ruby/language/delegation_spec.rb
+++ b/spec/ruby/language/delegation_spec.rb
@@ -31,10 +31,10 @@ describe "delegation with def(...)" do
         def delegate(...)
           target ...
         end
-       RUBY
-     end
+      RUBY
+    end
 
-     a.new.delegate(1, b: 2).should == Range.new([[], {}], nil, true)
+    a.new.delegate(1, b: 2).should == Range.new([[], {}], nil, true)
   end
 end
 
@@ -61,3 +61,33 @@ describe "delegation with def(x, ...)" do
     a.new.delegate_block(0, 1, b: 2) { |x| x }.should == [{b: 2}, [1]]
   end
 end
+
+ruby_version_is "3.2" do
+  describe "delegation with def(*)" do
+    it "delegates rest" do
+      a = Class.new(DelegationSpecs::Target)
+      a.class_eval(<<-RUBY)
+      def delegate(*)
+        target(*)
+      end
+    RUBY
+
+      a.new.delegate(0, 1).should == [[0, 1], {}]
+    end
+  end
+end
+
+ruby_version_is "3.2" do
+  describe "delegation with def(**)" do
+    it "delegates kwargs" do
+      a = Class.new(DelegationSpecs::Target)
+      a.class_eval(<<-RUBY)
+      def delegate(**)
+        target(**)
+      end
+    RUBY
+
+      a.new.delegate(a: 1) { |x| x }.should == [[], {a: 1}]
+    end
+  end
+end
diff --git a/spec/ruby/language/fixtures/rescue/top_level.rb b/spec/ruby/language/fixtures/rescue/top_level.rb
new file mode 100644
index 0000000000..59e78ef1d6
--- /dev/null
+++ b/spec/ruby/language/fixtures/rescue/top_level.rb
@@ -0,0 +1,7 @@
+# capturing in local variable at top-level
+
+begin
+  raise "message"
+rescue => e
+  ScratchPad << e.message
+end
diff --git a/spec/ruby/language/fixtures/super.rb b/spec/ruby/language/fixtures/super.rb
index 94a2a91be0..c5bdcf0e40 100644
--- a/spec/ruby/language/fixtures/super.rb
+++ b/spec/ruby/language/fixtures/super.rb
@@ -539,6 +539,30 @@ module SuperSpecs
         args
       end
 
+      def m3(*args)
+        args
+      end
+
+      def m4(*args)
+        args
+      end
+
+      def m_default(*args)
+        args
+      end
+
+      def m_rest(*args)
+        args
+      end
+
+      def m_pre_default_rest_post(*args)
+        args
+      end
+
+      def m_kwrest(**kw)
+        kw
+      end
+
       def m_modified(*args)
         args
       end
@@ -549,6 +573,30 @@ module SuperSpecs
         super
       end
 
+      def m3(_, _, _)
+        super
+      end
+
+      def m4(_, _, _, _)
+        super
+      end
+
+      def m_default(_ = 0)
+        super
+      end
+
+      def m_rest(*_)
+        super
+      end
+
+      def m_pre_default_rest_post(_, _, _=:a, _=:b, *_, _, _)
+        super
+      end
+
+      def m_kwrest(**_)
+        super
+      end
+
       def m_modified(_, _)
         _ = 14
         super
diff --git a/spec/ruby/language/method_spec.rb b/spec/ruby/language/method_spec.rb
index 5f42c52341..e34ff7e1a6 100644
--- a/spec/ruby/language/method_spec.rb
+++ b/spec/ruby/language/method_spec.rb
@@ -1335,6 +1335,7 @@ describe "An endless method definition" do
     end
   end
 
+  # tested more thoroughly in language/delegation_spec.rb
   context "with args forwarding" do
     evaluate <<-ruby do
         def mm(word, num:)
diff --git a/spec/ruby/language/optional_assignments_spec.rb b/spec/ruby/language/optional_assignments_spec.rb
index 02461655d6..2443cc6b79 100644
--- a/spec/ruby/language/optional_assignments_spec.rb
+++ b/spec/ruby/language/optional_assignments_spec.rb
@@ -57,7 +57,7 @@ describe 'Optional variable assignments' do
       end
     end
 
-    describe 'using a accessor' do
+    describe 'using an accessor' do
       before do
         klass = Class.new { attr_accessor :b }
         @a    = klass.new
@@ -103,6 +103,16 @@ describe 'Optional variable assignments' do
         @a.b.should == 10
       end
 
+      it 'does evaluate receiver only once when assigns' do
+        ScratchPad.record []
+        @a.b = nil
+
+        (ScratchPad << :evaluated; @a).b ||= 10
+
+        ScratchPad.recorded.should == [:evaluated]
+        @a.b.should == 10
+      end
+
       it 'returns the new value if set to false' do
         def @a.b=(x)
           :v
@@ -122,29 +132,148 @@ describe 'Optional variable assignments' do
         (@a.b ||= 20).should == 10
       end
 
-      it 'works when writer is private' do
+      it 'ignores method visibility when receiver is self' do
+        klass_with_private_methods = Class.new do
+          def initialize(v) @a = v end
+          def public_method(v); self.a ||= v end
+          private
+          def a; @a end
+          def a=(v) @a = v; 42 end
+        end
+
+        a = klass_with_private_methods.new(false)
+        a.public_method(10).should == 10
+      end
+    end
+
+    describe 'using a #[]' do
+      before do
+        @a = {}
         klass = Class.new do
-          def t
-            self.b = false
-            (self.b ||= 10).should == 10
-            (self.b ||= 20).should == 10
+          def [](k)
+            @hash ||= {}
+            @hash[k]
+          end
+
+          def []=(k, v)
+            @hash ||= {}
+            @hash[k] = v
+            7
           end
+        end
+        @b = klass.new
+      end
+
+      it 'returns the assigned value, not the result of the []= method with ||=' do
+        (@b[:k] ||= 12).should == 12
+      end
+
+      it "evaluates the index precisely once" do
+        ary = [:x, :y]
+        @a[:x] = 15
+        @a[ary.pop] ||= 25
+        ary.should == [:x]
+        @a.should == { x: 15, y: 25 }
+      end
 
-          def b
-            @b
+      it "evaluates the index arguments in the correct order" do
+        ary = Class.new(Array) do
+          def [](x, y)
+            super(x + 3 * y)
           end
 
-          def b=(x)
-            @b = x
-            :v
+          def []=(x, y, value)
+            super(x + 3 * y, value)
           end
+        end.new
+        ary[0, 0] = 1
+        ary[1, 0] = 1
+        ary[2, 0] = nil
+        ary[3, 0] = 1
+        ary[4, 0] = 1
+        ary[5, 0] = 1
+        ary[6, 0] = nil
+
+        foo = [0, 2]
+
+        ary[foo.pop, foo.pop] ||= 2 # expected `ary[2, 0] ||= 2`
+
+        ary[2, 0].should == 2
+        ary[6, 0].should == nil # returns the same element as `ary[0, 2]`
+      end
+
+      it 'evaluates receiver only once when assigns' do
+        ScratchPad.record []
+        @a[:k] = nil
 
-          private :b=
+        (ScratchPad << :evaluated; @a)[:k] ||= 2
+
+        ScratchPad.recorded.should == [:evaluated]
+        @a[:k].should == 2
+      end
+
+      it 'ignores method visibility when receiver is self' do
+        klass_with_private_methods = Class.new do
+          def initialize(h) @a = h end
+          def public_method(k, v); self[k] ||= v end
+          private
+          def [](k) @a[k] end
+          def []=(k, v) @a[k] = v; 42 end
         end
 
-        klass.new.t
+        a = klass_with_private_methods.new(k: false)
+        a.public_method(:k, 10).should == 10
       end
 
+      context 'splatted argument' do
+        it 'correctly handles it' do
+          (@b[*[:m]] ||= 10).should == 10
+          @b[:m].should == 10
+
+          (@b[*(1; [:n])] ||= 10).should == 10
+          @b[:n].should == 10
+
+          (@b[*begin 1; [:k] end] ||= 10).should == 10
+          @b[:k].should == 10
+        end
+
+        it 'calls #to_a only once' do
+          k = Object.new
+          def k.to_a
+            ScratchPad << :to_a
+            [:k]
+          end
+
+          ScratchPad.record []
+          (@b[*k] ||= 20).should == 20
+          @b[:k].should == 20
+          ScratchPad.recorded.should == [:to_a]
+        end
+
+        it 'correctly handles a nested splatted argument' do
+          (@b[*[*[:k]]] ||= 20).should == 20
+          @b[:k].should == 20
+        end
+
+        it 'correctly handles multiple nested splatted arguments' do
+          klass_with_multiple_parameters = Class.new do
+            def [](k1, k2, k3)
+              @hash ||= {}
+              @hash[:"#{k1}#{k2}#{k3}"]
+            end
+
+            def []=(k1, k2, k3, v)
+              @hash ||= {}
+              @hash[:"#{k1}#{k2}#{k3}"] = v
+              7
+            end
+          end
+          a = klass_with_multiple_parameters.new
+
+          (a[*[:a], *[:b], *[:c]] ||= 20).should == 20
+          a[:a, :b, :c].should == 20
+        end
+      end
     end
   end
 
@@ -191,7 +320,7 @@ describe 'Optional variable assignments' do
       end
     end
 
-    describe 'using a single variable' do
+    describe 'using an accessor' do
       before do
         klass = Class.new { attr_accessor :b }
         @a    = klass.new
@@ -236,6 +365,29 @@ describe 'Optional variable assignments' do
 
         @a.b.should == 20
       end
+
+      it 'does evaluate receiver only once when assigns' do
+        ScratchPad.record []
+        @a.b = 10
+
+        (ScratchPad << :evaluated; @a).b &&= 20
+
+        ScratchPad.recorded.should == [:evaluated]
+        @a.b.should == 20
+      end
+
+      it 'ignores method visibility when receiver is self' do
+        klass_with_private_methods = Class.new do
+          def initialize(v) @a = v end
+          def public_method(v); self.a &&= v end
+          private
+          def a; @a end
+          def a=(v) @a = v; 42 end
+        end
+
+        a = klass_with_private_methods.new(true)
+        a.public_method(10).should == 10
+      end
     end
 
     describe 'using a #[]' do
@@ -297,17 +449,15 @@ describe 'Optional variable assignments' do
       end
 
       it 'returns the assigned value, not the result of the []= method with ||=' do
-        (@b[:k] ||= 12).should == 12
-      end
-
-      it 'correctly handles a splatted argument for the index' do
-        (@b[*[:k]] ||= 12).should == 12
+        @b[:k] = 10
+        (@b[:k] &&= 12).should == 12
       end
 
       it "evaluates the index precisely once" do
         ary = [:x, :y]
         @a[:x] = 15
-        @a[ary.pop] ||= 25
+        @a[:y] = 20
+        @a[ary.pop] &&= 25
         ary.should == [:x]
         @a.should == { x: 15, y: 25 }
       end
@@ -324,24 +474,103 @@ describe 'Optional variable assignments' do
         end.new
         ary[0, 0] = 1
         ary[1, 0] = 1
-        ary[2, 0] = nil
+        ary[2, 0] = 1
         ary[3, 0] = 1
         ary[4, 0] = 1
         ary[5, 0] = 1
-        ary[6, 0] = nil
+        ary[6, 0] = 1
 
         foo = [0, 2]
 
-        ary[foo.pop, foo.pop] ||= 2
+        ary[foo.pop, foo.pop] &&= 2 # expected `ary[2, 0] &&= 2`
 
         ary[2, 0].should == 2
-        ary[6, 0].should == nil
+        ary[6, 0].should == 1 # returns the same element as `ary[0, 2]`
+      end
+
+      it 'evaluates receiver only once when assigns' do
+        ScratchPad.record []
+        @a[:k] = 1
+
+        (ScratchPad << :evaluated; @a)[:k] &&= 2
+
+        ScratchPad.recorded.should == [:evaluated]
+        @a[:k].should == 2
       end
 
       it 'returns the assigned value, not the result of the []= method with +=' do
         @b[:k] = 17
         (@b[:k] += 12).should == 29
       end
+
+      it 'ignores method visibility when receiver is self' do
+        klass_with_private_methods = Class.new do
+          def initialize(h) @a = h end
+          def public_method(k, v); self[k] &&= v end
+          private
+          def [](k) @a[k] end
+          def []=(k, v) @a[k] = v; 42 end
+        end
+
+        a = klass_with_private_methods.new(k: true)
+        a.public_method(:k, 10).should == 10
+      end
+
+      context 'splatted argument' do
+        it 'correctly handles it' do
+          @b[:m] = 0
+          (@b[*[:m]] &&= 10).should == 10
+          @b[:m].should == 10
+
+          @b[:n] = 0
+          (@b[*(1; [:n])] &&= 10).should == 10
+          @b[:n].should == 10
+
+          @b[:k] = 0
+          (@b[*begin 1; [:k] end] &&= 10).should == 10
+          @b[:k].should == 10
+        end
+
+        it 'calls #to_a only once' do
+          k = Object.new
+          def k.to_a
+            ScratchPad << :to_a
+            [:k]
+          end
+
+          ScratchPad.record []
+          @b[:k] = 10
+          (@b[*k] &&= 20).should == 20
+          @b[:k].should == 20
+          ScratchPad.recorded.should == [:to_a]
+        end
+
+        it 'correctly handles a nested splatted argument' do
+          @b[:k] = 10
+          (@b[*[*[:k]]] &&= 20).should == 20
+          @b[:k].should == 20
+        end
+
+        it 'correctly handles multiple nested splatted arguments' do
+          klass_with_multiple_parameters = Class.new do
+            def [](k1, k2, k3)
+              @hash ||= {}
+              @hash[:"#{k1}#{k2}#{k3}"]
+            end
+
+            def []=(k1, k2, k3, v)
+              @hash ||= {}
+              @hash[:"#{k1}#{k2}#{k3}"] = v
+              7
+            end
+          end
+          a = klass_with_multiple_parameters.new
+
+          a[:a, :b, :c] = 10
+          (a[*[:a], *[:b], *[:c]] &&= 20).should == 20
+          a[:a, :b, :c].should == 20
+        end
+      end
     end
   end
 
@@ -434,7 +663,7 @@ describe 'Optional constant assignment' do
       ConstantSpecs::ClassA::OR_ASSIGNED_CONSTANT2.should == :assigned
     end
 
-    it 'causes side-effects of the module part to be applied (for nil constant)' do
+    it 'causes side-effects of the module part to be applied only once (for nil constant)' do
       suppress_warning do # already initialized constant
       ConstantSpecs::ClassA::NIL_OR_ASSIGNED_CONSTANT2 = nil
       x = 0
@@ -492,5 +721,20 @@ describe 'Optional constant assignment' do
       ConstantSpecs::OpAssignFalse.should == false
       ConstantSpecs.send :remove_const, :OpAssignFalse
     end
+
+    it 'causes side-effects of the module part to be applied only once (when assigns)' do
+      module ConstantSpecs
+        OpAssignTrue = true
+      end
+
+      suppress_warning do # already initialized constant
+        x = 0
+        (x += 1; ConstantSpecs)::OpAssignTrue &&= :assigned
+        x.should == 1
+        ConstantSpecs::OpAssignTrue.should == :assigned
+      end
+
+      ConstantSpecs.send :remove_const, :OpAssignTrue
+    end
   end
 end
diff --git a/spec/ruby/language/pattern_matching_spec.rb b/spec/ruby/language/pattern_matching_spec.rb
index 050a8a052d..a8ec078cd0 100644
--- a/spec/ruby/language/pattern_matching_spec.rb
+++ b/spec/ruby/language/pattern_matching_spec.rb
@@ -207,7 +207,7 @@ describe "Pattern matching" do
         in []
         end
       RUBY
-    }.should raise_error(SyntaxError, /syntax error, unexpected `in'|\(eval\):3: syntax error, unexpected keyword_in/)
+    }.should raise_error(SyntaxError, /syntax error, unexpected `in'|\(eval\):3: syntax error, unexpected keyword_in|unexpected 'in'/)
 
     -> {
       eval <<~RUBY
@@ -216,7 +216,7 @@ describe "Pattern matching" do
         when 1 == 1
         end
       RUBY
-    }.should raise_error(SyntaxError, /syntax error, unexpected `when'|\(eval\):3: syntax error, unexpected keyword_when/)
+    }.should raise_error(SyntaxError, /syntax error, unexpected `when'|\(eval\):3: syntax error, unexpected keyword_when|unexpected 'when'/)
   end
 
   it "checks patterns until the first matching" do
@@ -273,7 +273,7 @@ describe "Pattern matching" do
           true
         end
       RUBY
-    }.should raise_error(SyntaxError, /unexpected/)
+    }.should raise_error(SyntaxError, /unexpected|expected a delimiter after the predicates of a `when` clause/)
   end
 
   it "evaluates the case expression once for multiple patterns, caching the result" do
@@ -739,6 +739,20 @@ describe "Pattern matching" do
       RUBY
     end
 
+    it "checks Constant === object before calling #deconstruct" do
+      c1 = Class.new
+      obj = c1.new
+      obj.should_not_receive(:deconstruct)
+      eval(<<~RUBY).should == false
+        case obj
+        in String[1]
+          true
+        else
+          false
+        end
+      RUBY
+    end
+
     it "does not match object without #deconstruct method" do
       obj = Object.new
       obj.should_receive(:respond_to?).with(:deconstruct)
@@ -770,11 +784,7 @@ describe "Pattern matching" do
     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
+        Class.new(Array).new([0, 1])
       end
 
       eval(<<~RUBY).should == true
@@ -1004,7 +1014,7 @@ describe "Pattern matching" do
           in {"a" => 1}
           end
         RUBY
-      }.should raise_error(SyntaxError, /unexpected/)
+      }.should raise_error(SyntaxError, /unexpected|expected a label as the key in the hash pattern/)
     end
 
     it "does not support string interpolation in keys" do
@@ -1016,7 +1026,7 @@ describe "Pattern matching" do
           in {"#{x}": 1}
           end
         RUBY
-      }.should raise_error(SyntaxError, /symbol literal with interpolation is not allowed/)
+      }.should raise_error(SyntaxError, /symbol literal with interpolation is not allowed|expected a label as the key in the hash pattern/)
     end
 
     it "raise SyntaxError when keys duplicate in pattern" do
@@ -1072,6 +1082,20 @@ describe "Pattern matching" do
       RUBY
     end
 
+    it "checks Constant === object before calling #deconstruct_keys" do
+      c1 = Class.new
+      obj = c1.new
+      obj.should_not_receive(:deconstruct_keys)
+      eval(<<~RUBY).should == false
+        case obj
+        in String(a: 1)
+          true
+        else
+          false
+        end
+      RUBY
+    end
+
     it "does not match object without #deconstruct_keys method" do
       obj = Object.new
       obj.should_receive(:respond_to?).with(:deconstruct_keys)
@@ -1232,6 +1256,37 @@ describe "Pattern matching" do
       RUBY
     end
 
+    it "in {} only matches empty hashes" do
+      eval(<<~RUBY).should == false
+        case {a: 1}
+        in {}
+          true
+        else
+          false
+        end
+      RUBY
+    end
+
+    it "in {**nil} only matches empty hashes" do
+      eval(<<~RUBY).should == true
+        case {}
+        in {**nil}
+          true
+        else
+          false
+        end
+      RUBY
+
+      eval(<<~RUBY).should == false
+        case {a: 1}
+        in {**nil}
+          true
+        else
+          false
+        end
+      RUBY
+    end
+
     it "matches anything with **" do
       eval(<<~RUBY).should == true
         case {a: 1}
@@ -1340,76 +1395,115 @@ describe "Pattern matching" do
     end
   end
 
-  ruby_version_is "3.1" do
-    it "can omit parentheses in one line pattern matching" do
-      eval(<<~RUBY).should == [1, 2]
-        [1, 2] => a, b
-        [a, b]
-      RUBY
+  describe "Ruby 3.1 improvements" do
+    ruby_version_is "3.1" do
+      it "can omit parentheses in one line pattern matching" do
+        eval(<<~RUBY).should == [1, 2]
+          [1, 2] => a, b
+          [a, b]
+        RUBY
 
-      eval(<<~RUBY).should == 1
-        {a: 1} => a:
-        a
-      RUBY
-    end
+        eval(<<~RUBY).should == 1
+          {a: 1} => a:
+          a
+        RUBY
+      end
 
-    it "supports pinning instance variables" do
-      eval(<<~RUBY).should == true
-        @a = /a/
-        case 'abc'
-        in ^@a
-          true
+      it "supports pinning instance variables" do
+        eval(<<~RUBY).should == true
+          @a = /a/
+          case 'abc'
+          in ^@a
+            true
+          end
+        RUBY
+      end
+
+      it "supports pinning class variables" do
+        result = nil
+        Module.new do
+          result = module_eval(<<~RUBY)
+            @@a = 0..10
+
+            case 2
+            in ^@@a
+              true
+            end
+          RUBY
         end
-      RUBY
-    end
 
-    it "supports pinning class variables" do
-      result = nil
-      Module.new do
-        result = module_eval(<<~RUBY)
-          @@a = 0..10
+        result.should == true
+      end
 
-          case 2
-          in ^@@a
+      it "supports pinning global variables" do
+        eval(<<~RUBY).should == true
+          $a = /a/
+          case 'abc'
+          in ^$a
             true
           end
         RUBY
       end
 
-      result.should == true
+      it "supports pinning expressions" do
+        eval(<<~RUBY).should == true
+          case 'abc'
+            in ^(/a/)
+            true
+          end
+        RUBY
+
+        eval(<<~RUBY).should == true
+          case 0
+          in ^(0+0)
+            true
+          end
+        RUBY
+      end
+
+      it "supports pinning expressions in array pattern" do
+        eval(<<~RUBY).should == true
+          case [3]
+          in [^(1+2)]
+            true
+          end
+        RUBY
+      end
+
+      it "supports pinning expressions in hash pattern" do
+        eval(<<~RUBY).should == true
+          case {name: '2.6', released_at: Time.new(2018, 12, 25)}
+            in {released_at: ^(Time.new(2010)..Time.new(2020))}
+            true
+          end
+        RUBY
+      end
     end
+  end
 
-    it "supports pinning global variables" do
-      eval(<<~RUBY).should == true
-        $a = /a/
-        case 'abc'
-        in ^$a
-          true
-        end
-      RUBY
+  describe "value in pattern" do
+    it "returns true if the pattern matches" do
+      eval("1 in 1").should == true
+
+      eval("1 in Integer").should == true
+
+      e = nil
+      eval("[1, 2] in [1, e]").should == true
+      e.should == 2
+
+      k = nil
+      eval("{k: 1} in {k:}").should == true
+      k.should == 1
     end
 
-    it "supports pinning expressions" do
-      eval(<<~RUBY).should == true
-        case 'abc'
-          in ^(/a/)
-          true
-        end
-      RUBY
+    it "returns false if the pattern does not match" do
+      eval("1 in 2").should == false
 
-      eval(<<~RUBY).should == true
-        case {name: '2.6', released_at: Time.new(2018, 12, 25)}
-          in {released_at: ^(Time.new(2010)..Time.new(2020))}
-          true
-        end
-      RUBY
+      eval("1 in Float").should == false
 
-      eval(<<~RUBY).should == true
-        case 0
-        in ^(0+0)
-          true
-        end
-      RUBY
+      eval("[1, 2] in [2, e]").should == false
+
+      eval("{k: 1} in {k: 2}").should == false
     end
   end
 end
diff --git a/spec/ruby/language/rescue_spec.rb b/spec/ruby/language/rescue_spec.rb
index b91b52fa0f..69ed038fda 100644
--- a/spec/ruby/language/rescue_spec.rb
+++ b/spec/ruby/language/rescue_spec.rb
@@ -61,6 +61,78 @@ describe "The rescue keyword" do
     end
   end
 
+  describe 'capturing in a local variable (that defines it)' do
+    it 'captures successfully in a method' do
+      ScratchPad.record []
+
+      def a
+        raise "message"
+      rescue => e
+        ScratchPad << e.message
+      end
+
+      a
+      ScratchPad.recorded.should == ["message"]
+    end
+
+    it 'captures successfully in a block' do
+      ScratchPad.record []
+
+      p = proc do
+        raise "message"
+      rescue => e
+        ScratchPad << e.message
+      end
+
+      p.call
+      ScratchPad.recorded.should == ["message"]
+    end
+
+    it 'captures successfully in a class' do
+      ScratchPad.record []
+
+      class RescueSpecs::C
+        raise "message"
+      rescue => e
+        ScratchPad << e.message
+      end
+
+      ScratchPad.recorded.should == ["message"]
+    end
+
+    it 'captures successfully in a module' do
+      ScratchPad.record []
+
+      module RescueSpecs::M
+        raise "message"
+      rescue => e
+        ScratchPad << e.message
+      end
+
+      ScratchPad.recorded.should == ["message"]
+    end
+
+    it 'captures sucpcessfully in a singleton class' do
+      ScratchPad.record []
+
+      class << Object.new
+        raise "message"
+      rescue => e
+        ScratchPad << e.message
+      end
+
+      ScratchPad.recorded.should == ["message"]
+    end
+
+    it 'captures successfully at the top-level' do
+      ScratchPad.record []
+
+      require_relative 'fixtures/rescue/top_level'
+
+      ScratchPad.recorded.should == ["message"]
+    end
+  end
+
   it "returns value from `rescue` if an exception was raised" do
     begin
       raise
diff --git a/spec/ruby/language/safe_navigator_spec.rb b/spec/ruby/language/safe_navigator_spec.rb
index c3aecff2dd..b1e28c3963 100644
--- a/spec/ruby/language/safe_navigator_spec.rb
+++ b/spec/ruby/language/safe_navigator_spec.rb
@@ -7,43 +7,43 @@ describe "Safe navigator" do
 
   context "when context is nil" do
     it "always returns nil" do
-      eval("nil&.unknown").should == nil
-      eval("[][10]&.unknown").should == nil
+      nil&.unknown.should == nil
+      [][10]&.unknown.should == nil
     end
 
     it "can be chained" do
-      eval("nil&.one&.two&.three").should == nil
+      nil&.one&.two&.three.should == nil
     end
 
     it "doesn't evaluate arguments" do
       obj = Object.new
       obj.should_not_receive(:m)
-      eval("nil&.unknown(obj.m) { obj.m }")
+      nil&.unknown(obj.m) { obj.m }
     end
   end
 
   context "when context is false" do
     it "calls the method" do
-      eval("false&.to_s").should == "false"
+      false&.to_s.should == "false"
 
-      -> { eval("false&.unknown") }.should raise_error(NoMethodError)
+      -> { false&.unknown }.should raise_error(NoMethodError)
     end
   end
 
   context "when context is truthy" do
     it "calls the method" do
-      eval("1&.to_s").should == "1"
+      1&.to_s.should == "1"
 
-      -> { eval("1&.unknown") }.should raise_error(NoMethodError)
+      -> { 1&.unknown }.should raise_error(NoMethodError)
     end
   end
 
   it "takes a list of arguments" do
-    eval("[1,2,3]&.first(2)").should == [1,2]
+    [1,2,3]&.first(2).should == [1,2]
   end
 
   it "takes a block" do
-    eval("[1,2]&.map { |i| i * 2 }").should == [2, 4]
+    [1,2]&.map { |i| i * 2 }.should == [2, 4]
   end
 
   it "allows assignment methods" do
@@ -56,29 +56,77 @@ describe "Safe navigator" do
     end
     obj = klass.new
 
-    eval("obj&.foo = 3").should == 3
+    (obj&.foo = 3).should == 3
     obj.foo.should == 3
 
     obj = nil
-    eval("obj&.foo = 3").should == nil
+    (obj&.foo = 3).should == nil
   end
 
   it "allows assignment operators" do
     klass = Class.new do
-      attr_accessor :m
+      attr_reader :m
 
       def initialize
         @m = 0
       end
+
+      def m=(v)
+        @m = v
+        42
+      end
     end
 
     obj = klass.new
 
-    eval("obj&.m += 3")
+    obj&.m += 3
     obj.m.should == 3
 
     obj = nil
-    eval("obj&.m += 3").should == nil
+    (obj&.m += 3).should == nil
+  end
+
+  it "allows ||= operator" do
+    klass = Class.new do
+      attr_reader :m
+
+      def initialize
+        @m = false
+      end
+
+      def m=(v)
+        @m = v
+        42
+      end
+    end
+
+    obj = klass.new
+
+    (obj&.m ||= true).should == true
+    obj.m.should == true
+
+    obj = nil
+    (obj&.m ||= true).should == nil
+    obj.should == nil
+  end
+
+  it "allows &&= operator" do
+    klass = Class.new do
+      attr_accessor :m
+
+      def initialize
+        @m = true
+      end
+    end
+
+    obj = klass.new
+
+    (obj&.m &&= false).should == false
+    obj.m.should == false
+
+    obj = nil
+    (obj&.m &&= false).should == nil
+    obj.should == nil
   end
 
   it "does not call the operator method lazily with an assignment operator" do
@@ -91,7 +139,7 @@ describe "Safe navigator" do
     obj = klass.new
 
     -> {
-      eval("obj&.foo += 3")
+      obj&.foo += 3
     }.should raise_error(NoMethodError) { |e|
       e.name.should == :+
     }
diff --git a/spec/ruby/language/super_spec.rb b/spec/ruby/language/super_spec.rb
index d22c603605..a98b3b3091 100644
--- a/spec/ruby/language/super_spec.rb
+++ b/spec/ruby/language/super_spec.rb
@@ -335,6 +335,13 @@ describe "The super keyword" do
 
   it "without explicit arguments that are '_'" do
     SuperSpecs::ZSuperWithUnderscores::B.new.m(1, 2).should == [1, 2]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m3(1, 2, 3).should == [1, 2, 3]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m4(1, 2, 3, 4).should == [1, 2, 3, 4]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m_default(1).should == [1]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m_default.should == [0]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m_pre_default_rest_post(1, 2, 3, 4, 5, 6, 7).should == [1, 2, 3, 4, 5, 6, 7]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m_rest(1, 2).should == [1, 2]
+    SuperSpecs::ZSuperWithUnderscores::B.new.m_kwrest(a: 1).should == {a: 1}
   end
 
   it "without explicit arguments that are '_' including any modifications" do
diff --git a/spec/ruby/language/variables_spec.rb b/spec/ruby/language/variables_spec.rb
index 23c2cdb557..53d191b456 100644
--- a/spec/ruby/language/variables_spec.rb
+++ b/spec/ruby/language/variables_spec.rb
@@ -367,8 +367,13 @@ describe "Multiple assignment" do
 
     it "assigns indexed elements" do
       a = []
-      a[1], a[2] = 1
-      a.should == [nil, 1, nil]
+      a[1], a[2] = 1, 2
+      a.should == [nil, 1, 2]
+
+      # with splatted argument
+      a = []
+      a[*[1]], a[*[2]] = 1, 2
+      a.should == [nil, 1, 2]
     end
 
     it "assigns constants" do