MatchData#named_captures: add optional symbolize_names keyword (#6952)

core/matchdata/named_captures_spec.rb

@@ -12,4 +12,16 @@
   it 'returns the latest matched capture, even if a later one that does not match exists' do
     /\A(?<a>.)(?<b>.)(?<b>.)(?<a>.)?\z/.match('012').named_captures.should == { 'a' => '0', 'b' => '2' }
   end
+
+  ruby_version_is "3.3" do
+    it 'returns a Hash with Symbol keys when symbolize_names is provided a true value' do
+      /(?<a>.)(?<b>.)?/.match('0').named_captures(symbolize_names: true).should == { a: '0', b: nil }
+      /(?<a>.)(?<b>.)?/.match('0').named_captures(symbolize_names: "truly").should == { a: '0', b: nil }
+    end
+
+    it 'returns a Hash with String keys when symbolize_names is provided a false value' do
+      /(?<a>.)(?<b>.)?/.match('02').named_captures(symbolize_names: false).should == { 'a' => '0', 'b' => '2' }
+      /(?<a>.)(?<b>.)?/.match('02').named_captures(symbolize_names: nil).should == { 'a' => '0', 'b' => '2' }
+    end
+  end
 end