Default to document when element has no parent in match selector query

History.md

@@ -1,3 +1,10 @@
+# Version 3.7.2
+Release date: unreleased
+
+### Fixed
+
+* Fix MatchQuery based matchers when used on a root element found using any type of parent/ancestor query - Issue #2097
+
 # Version 3.7.1
 Release date: 2018-09-05
 

lib/capybara/node/matchers.rb

@@ -713,7 +713,7 @@ module Capybara
         query_args = _set_query_session_options(*query_args)
         query = Capybara::Queries::MatchQuery.new(*query_args, &optional_filter_block)
         synchronize(query.wait) do
-          yield query.resolve_for(first(:xpath, './parent::*', minimum: 0) || query_scope)
+          yield query.resolve_for(first(:xpath, './parent::*', minimum: 0) || session&.document || query_scope)
         end
         true
       end

lib/capybara/session.rb

@@ -364,7 +364,7 @@ module Capybara
     # @overload switch_to_frame(element)
     #   @param [Capybara::Node::Element]  iframe/frame element to switch to
     # @overload switch_to_frame(:parent)
-    #   Switch to the parent element
+    #   Switch to the parent frame
     # @overload switch_to_frame(:top)
     #   Switch to the top level document
     #

lib/capybara/spec/session/element/match_css_spec.rb

@@ -22,4 +22,10 @@ Capybara::SpecHelper.spec '#match_css?' do
     expect(@element).to match_css('span') { |el| el[:class] == 'number' }
     expect(@element).not_to match_css('span') { |el| el[:class] == 'not_number' }
   end
+
+  it 'should work with root element found via ancestor' do
+    el = @session.find(:css, 'body').find(:xpath, '..')
+    expect(el).to match_css('html')
+    expect { expect(el).to not_match_css('html') }.to raise_exception(RSpec::Expectations::ExpectationNotMetError)
+  end
 end