You can bypass the validation by using #click!
instead of #click
. Basically, this triggers the click via JavaScript rather than through standard Selenium commands.
browser = Watir::Browser.new
browser.goto('www.google.com')
browser.text_field(name: 'q').set('watir')
browser.button(name: 'btnK').click!
If you are only using Selenium, you can do:
btn = driver.find_element(name: 'btnK')
driver.execute_script('arguments[0].click();', btn)
As discussed in the comments, you could also close the suggestions box before trying to click the button. You can do this by moving focus to any other element - eg the first link on the page. Depending on what you're testing, this may or may not have value.
browser.text_field(name: 'q').set('watir')
browser.link.focus # move focus to any other element so suggestions close
browser.button(name: 'btnK').click