Raise error if only x or only y are provided for click offset

lib/capybara/node/element.rb

@@ -153,7 +153,9 @@ module Capybara
       #     @option offset [Integer] y  Y coordinate to offset the click location from the top left corner of the element
       # @return [Capybara::Node::Element]  The element
       def click(*keys, wait: nil, **offset)
-        synchronize(wait) { base.click(keys, offset) }
+        raise ArgumentError, 'You must specify both x: and y: for a click offset' if nil ^ offset[:x] ^ offset[:y]
+
+        synchronize(wait) { base.click(Array(keys), offset) }
         self
       end
 

lib/capybara/spec/session/node_spec.rb

@@ -406,6 +406,13 @@ Capybara::SpecHelper.spec 'node' do
       expect(locations[:y].to_f).to be_within(1).of(5)
     end
 
+    it 'should raise error if both x and y values are not passed' do
+      @session.visit('with_js')
+      el = @session.find(:css, '#click-test')
+      expect { el.click(x: 5) }.to raise_error ArgumentError
+      expect { el.click(x: nil, y: 3) }.to raise_error ArgumentError
+    end
+
     it 'should be able to click a table row', requires: [:js] do
       @session.visit('/tables')
       tr = @session.find(:css, '#agent_table tr:first-child').click