Appium https://github.com/appium/appium/wiki/Automating-mobile-gestures

bug.rb

[9] pry(main)> @driver.execute_script 'mobile: tap', :tapCount => 1, :touchCount => 1, :duration => 0.1, :x => 0.8, :y => 0.4
:post
"session/6279234c-cd7c-40cb-8549-69c294c66147/execute"
{:script=>"mobile: tap", :args=>[{:tapCount=>1, :touchCount=>1, :duration=>0.1, :x=>0.8, :y=>0.4}]}

Selenium::WebDriver::Error::WebDriverError: unexpected response, code=400, content-type="text/html"
Parameters for mobile method did not match the definition. Required params must be sent as script args in this order: ["tapCount","touchCount","duration","x","y"]
from /selenium-webdriver-2.29.0/lib/selenium/webdriver/remote/http/common.rb:66:in 'create_response'

[10] pry(main)> a = {:script=>"mobile: tap", :args=>[{:tapCount=>1, :touchCount=>1, :duration=>0.1, :x=>0.8, :y=>0.4}]}.to_json; puts a
{"script":"mobile: tap","args":[{"tapCount":1,"touchCount":1,"duration":0.1,"x":0.8,"y":0.4}]}