true/false should verify attribute presence/absence in :element selector

lib/capybara/selector.rb

@@ -467,6 +467,10 @@ Capybara.add_selector(:element) do
     case val
     when Regexp
       xpath
+    when true
+      xpath[XPath.attr(name)]
+    when false
+      xpath[!XPath.attr(name)]
     when XPath::Expression
       xpath[XPath.attr(name)[val]]
     else
@@ -478,6 +482,12 @@ Capybara.add_selector(:element) do
     val.is_a?(Regexp) ? node[name] =~ val : true
   end
 
-  describe_expression_filters
+  describe_expression_filters do |**options|
+    booleans, values = options.partition {|k,v| [true, false].include? v }.map &:to_h
+    desc = describe_all_expression_filters(values)
+    desc += booleans.map do |k, v|
+      v ? " with #{k} attribute" : "without #{k} attribute"
+    end.join
+  end
 end
 # rubocop:enable Metrics/BlockLength

spec/selector_spec.rb

@@ -265,11 +265,21 @@ RSpec.describe Capybara do
           expect(string.find(:element, type: 'submit').value).to eq 'click me'
         end
 
+        it 'validates attribute presence when true' do
+          expect(string.find(:element, name: true)[:id]).to eq 'my_text_input'
+        end
+
+        it 'validates attribute absence when false' do
+          expect(string.find(:element, 'option', disabled: false, selected: false).value).to eq 'a'
+        end
+
         it 'includes wildcarded keys in description' do
-          expect { string.find(:element, 'input', not_there: 'bad', count: 1) }
+          expect { string.find(:element, 'input', not_there: 'bad', presence: true, absence: false, count: 1) }
             .to(raise_error do |e|
               expect(e).to be_a(Capybara::ElementNotFound)
               expect(e.message).to include 'not_there => bad'
+              expect(e.message).to include 'with presence attribute'
+              expect(e.message).to include 'without absence attribute'
               expect(e.message).not_to include 'count 1'
             end)
         end