You can find a documantaion about test automation methodologies which is described what is test automation and how we can do it effectively. This document is a brief but beneficial for whom want to start automate his test cases.
Selenium webdriver can drive different browsers like as Firefox, Chrome or Internet Explorer. These browsers actually cover the majority of internet users, so testing these browsers possibly covers the 90% of the internet users. However, there is no guaranty that the same automation scripts can work without a failure on these three browsers. For this reason, automation code should be error-prone for the browsers you want to cover. The following error is caught when the test script run for Chrome and Internet Explorer, but surprisingly there is no error for the Firefox. Selenium gives an error like below: Traceback (most recent call last): File "D:\workspace\sample_project\sample_run.py", line 10, in <module> m.login() File "D:\workspace\ sample_project \test_case_imps.py", line 335, in login driver.find_element_by_id("id_username").clear() File "C:\Python27\lib\site-packages\selenium-2.35.0-py2.7.egg\selenium\webdriver\r