Behat行为驱动开发是一种基于Gherkin语言的行为驱动开发(BDD)框架,它可以帮助你将需求用自然语言描述清楚,以此来推进业务开发过程,确保软件开发的质量。Cucumber是一个工具的名字,它帮您将需求用自然语言描述清楚,这样以便于沟通和协调。《Cucumber:行为驱动开发指南》是一本关于如何使用Cucumber工具来建立一个自动化测试系统的书籍 。
Behat行为驱动开发:探索、实践与优化
1. 简介
Behat是一种开源的BDD(行为驱动开发)框架,它允许开发者编写功能测试用例,并通过自然语言描述场景来实现这些测试用例,Behat的优势在于其灵活性和可扩展性,可以轻松地集成到各种项目中,本文将介绍Behat的基本概念、使用方法以及如何优化性能,帮助读者更好地理解和应用这一技术。
2. Behat基本概念
2.1 环境搭建
在开始使用Behat之前,需要先安装好相关工具和库,具体操作如下:
pip install robotframework pip install pybehat pip install selenium2-webdriver
2.2 步骤定义文件
在Behat中,每个测试用例都由一个或多个步骤组成,每个步骤都是一个Python函数,用于执行特定的操作,这些函数通常位于一个名为steps
的目录下,以.py
例如,一个简单的登录步骤可以定义为:
from behave import given, when, then from selenium import webdriver from selenium.webdriver.common.keys import Keys @given('I am on the login page') def step_impl(context): context.driver = webdriver.Firefox() context.driver.get("http://example.com/login") @when('I enter "{username}" and "{password}" in the fields') def step_impl(context, username, password): username_field = context.driver.find_element_by_name("username") password_field = context.driver.find_element_by_name("password") username_field.send_keys(username) password_field.send_keys(password) password_field.send_keys(Keys.RETURN) @then('I should see "Welcome, {username}!" on the page') def step_impl(context, username): assert "Welcome, {}!".format(username) in context.driver.page_source
2.3 特性标记和关键字
Behat提供了一些内置的特性标记和关键字,如@given
、@when
和@then
,分别用于定义给定条件、执行操作和验证结果,还可以通过自定义关键字来实现更复杂的功能,我们可以添加一个自定义关键字来检查页面上的某个元素是否存在:
from behave import given, when, then, expect, scenario, example from selenium import webdriver from selenium.common.exceptions import NoSuchElementException, StaleElementReferenceException from bs4 import BeautifulSoup as BS import time @given('I am on the homepage') def step_impl(context): context.driver = webdriver.Firefox() context.driver.get("http://example.com") @when('I wait for the element with id "{id}" to appear') def step_impl(context, id): max_wait = 10000 i = 0 while True: try: element = context.driver.find_element_by_id(id) break except (NoSuchElementException, StaleElementReferenceException): if i > max_wait: raise Exception("Timeout waiting for element") i += 1000 * i # exponential backoff for retries with increasing delay between attempts (to avoid rate limiting)" + str(i)) + "ms" + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str(timedelta(seconds=i))) + " " + str