Python + selenium automated test: page object mode

Page Objects yes selenium A test design pattern for , Think of each page as a class.class The main contents of the system include properties and methods , Attributes are not hard to understand , Is the element object in this page , For example, the input box for entering the user name , Input box for entering login password 、 Login button 、 Of this page url etc. . The method , It mainly refers to the specific functions that this page can provide .

01

Why choose POM？

Let's start with a simple code as follows ：

from selenium import webdriver

This is a simple little script . Script maintenance looks simple . But over time, the test suite grew . As you add more and more lines to your code , Things get tough . The main problem with script maintenance is , If 10 Different scripts use the same page elements , And any changes in that element , You need to change all 10 Script . This is a Time consuming and error prone .

A better way to maintain scripts is to create a separate class file , It can be found Web Elements , Fill in or verify them . This class can be used in In all scripts reusing . future , If web Elements change , We need to be in 1 Make changes in a class file , instead of 10 A different script .

02

What is? POM？

Page object model Is for Web UI Element creation Object Repository Design mode of .

Under this model , For every web page in the application , There should be corresponding page classes . this Page Class will find the Web Page WebElements, And it's also about these WebElements Page methods to perform operations .

The names of these methods should be given according to the task they are performing , namely If a loader is waiting for the payment gateway to appear ,POM The method name can be waitForPaymentScreenDisplay().

Below is a POM and POM Contrast figure ：

In automated testing , Introduced Page Object Model（POM）： Page object mode to solve ,POM Can make our test code more readable , High maintainability , High reusability .

POM The advantages of ：

• POM Provides a way to UI Layer operation 、 Business process and verification are separated , This makes the test code clearer and more readable .
• Object libraries are separated from use cases , Makes us better reuse objects , It can even be deeply combined with different tools .
• Reusable page method code will become more optimized .
• A more effective naming method makes it easier for us to know what the method operates UI Elements . For example, we want to go back to the home page , The method name is : gotoHomePage(), You can clearly know the specific function implementation through the method name .

03

Case description

Here is a simple and common login test case ：

def test_login_mail(self):
 driver = self.driver
 driver.get("http://www.xxx.xxx.com")
 driver.find_element_by_id("idInput").clear()
 driver.find_element_by_id("xxxxxxx").send_keys("xxxxx")
 driver.find_element_by_id("xxxxxxx").clear()
 driver.find_element_by_id("xxxxxxx").send_keys("xxxxxx")
 driver.find_element_by_id("loginBtn").click()

Then how can we carry out a transformation and upgrading ？

Reform case ideas ： 1. We're going to separate the test objects （ Element object ） And test scripts （ Use case scripts ）, So let's create two script files , Respectively ：LoginPage.py Used to define page element objects , Every element is encapsulated as a component （ It can be seen as a warehouse for storing page element objects ） CaseLoginTest.py Test case scripts .

2. The idea of design and implementation , All elements and their operation components are defined in Page page , Use case script page , By calling Page Component objects in , To piece together a login script .

BasePage.py：

#-*- coding: utf-8-*-

LoginPage.py：

#-*- coding: utf-8-*-
from selenium.webdriver.common.by importBy
import BasePage
# Inherit BasePage class 
class LoginPage(BasePage.Action):
# positioner , Locate the element object through the element attribute 
 username_loc=(By.ID,"idInput")
 password_loc =(By.ID,"pwdInput")
 submit_loc =(By.ID,"loginBtn")
 span_loc=(By.CSS_SELECTOR,"div.error-tt>p")
 dynpw_loc =(By.ID,"lbDynPw")
 userid_loc =(By.ID,"spnUid")

#Action
def open(self):
# call page Medium _open Open the connection 
self._open(self.base_url,self.pagetitle)
# call send_keys object , enter one user name 
def input_username(self, username):
 self.find_element(*self.username_loc).send_keys(username)
# call send_keys object , Input password 
def input_password(self, password):
 self.find_element(*self.password_loc).send_keys(password)
# call send_keys object , Click login 

def click_submit(self):
 self.find_element(*self.submit_loc).click()
# The user name or password is unreasonable Tip Box content display 
def show_span(self):
returnself.find_element(*self.span_loc).text
# Switch the login mode to dynamic password login （IE Effective under ）
def swich_DynPw(self):
 self.find_element(*self.dynpw_loc).click()
# Users in the login success page ID lookup 
def show_userid(self):
returnself.find_element(*self.userid_loc).text

Caselongintest.py：#-*- coding: utf-8-*-
import sys
reload(sys)
sys.setdef aultencoding('utf-8')
import unittest
from POimportLoginPage
from seleniumimport webdriver
classCaselogin126mail(unittest.TestCase):
"""
 Sign in case
 """
@classmethod
def setUpClass(cls):
 cls.driver = webdriver.Chrome()
 cls.driver.implicitly_wait(30)
 
 cls.url ="http://xxxx.xxx.com"
 cls.username ="xxxxx"
 cls.password ="xxxxx"
 
# Use case executor 
def test_login_mail(self):
# Statement LoginPage Class object 
login_page=LoginPage.LoginPage(self.driver, self.url, u”xxxxx”)
 
# Call the open page component 
login_page.open()
# Call the user name input component 
login_page.input_username(self.username)
# Call the password input component 
login_page.input_password(self.password)
# Call the click login button component 
login_page.click_submit()
@classmethod
def tearDownClass(cls):
 cls.driver.quit()
 
if __name__=="__main__":
 unittest.main()

Use POM Reconstruct the code structure after , It is found that the readability of code test case code is improved a lot , The way elements are written as components , You don't have to write every time findElement You can use components directly in scripts .

stay CaseLoginTest In the script case executor , Once we type in login_page And type in a point ,LoginPage The elements, objects and components in the page are displayed . also Defined PageObject Components can be reused in other scripts , Reduces the amount of code , It is also convenient for the maintenance and management of the script , When the attributes of an element change , We just need to deal with one PageObaject Change the definition of the object component in the page .

Finally, make a conclusion , Please enter all codes manually , Do not copy directly . Again POM Make a summary ：

• POM yes selenium webdriver Automatic test practice object library design pattern
• POM Make test scripts easier to maintain
• POM The elements are further optimized by means of object library 、 Use cases 、 Data maintenance organization