[笔记]Selenium Testing Tools Cookbook_Chapter5

Chapter 5 Synchronizing Tests

5.1 Synchronizing a test with an implicit wait

tc = unittest.TestCase()
driver.implicitly_wait(30)

button = driver.find_element_by_id("web-nav-app-download-btn")
button.click()
title = driver.find_element_by_class_name("slogan")
tc.assertEqual(title.text,"一个优质创作社区")
driver.find_element_by_class_name("logo").click()

Using an implicit wait may slow down tests when an application responds normally, as it will wait for each element appearing in the DOM and increase the overall execution time. Minimize or avoid using an implicit wait. Use an explicit wait, which provides more control when compared with an implicit wait.

5.2 Synchronizing a test with an explicit wait

The expected_conditions class provides a set of predefined conditions to wait for before proceeding further in the code. The following table shows some common conditions that we frequently come across when automating web browsers supported by the expected_conditions class

Predefined conditions	Selenium method
An element is visible and enabled	element_to_be_clickable(locator)
An element is selected	element_to_be_selected(element)
Presence of an element. This doesn't necessarily mean that the element is visible.	presence_of_element_located(locator)
Specific text present in an element	text_to_be_present_in_element(locator,text_)
An expectation for checking if the given text is present in the element's locator, text	text_to_be present_in_element_value
Title	title_contains(title)

button = driver.find_element_by_id("web-nav-app-download-btn")
button.click()

wait = WebDriverWait(driver,10)
wait.until(expected_conditions.title_contains("移动应用"))

5.3 Synchronizing a test with custom-expected conditions

button = driver.find_element_by_id("web-nav-app-download-btn")
button.click()

wait = WebDriverWait(driver,10)
wait.until(lambda driver: driver.find_element_by_class_name("logo"))

5.4 Synchronizing a test with FluentWait

There's no FluentWait class for Python's Selenium, but the WebDriverWait class has optional arguments for timeout, poll_frequency and ignored_exceptions.

from selenium.common.exceptions import *

button = driver.find_element_by_id("web-nav-app-download-btn")
button.click()

wait = WebDriverWait(driver,10,poll_frequency=1,ignored_exceptions=[ElementNotVisibleException])
wait.until(lambda driver: driver.find_element_by_class_name("logo"))