自动化测试用例之元素自愈：Playwright与pytest的结合使用

前言

在自动化测试领域，元素定位的准确性对于测试的成功至关重要。当使用Playwright结合pytest进行测试时，我们可以通过一些策略来增强测试的鲁棒性，特别是在元素定位失败时能够自动进行修复。本文将详细介绍如何实现这一过程。

环境准备

首先，确保你的环境中安装了playwright和pytest。可以通过以下命令安装：

pip install pytest
pip install playwright

自动化修复策略

在测试过程中捕获失败并尝试自动修复问题。我们将使用 Playwright 的 Locator 来定位元素，并在失败时重新定位更新元素。

BasePage类设计

BasePage类封装了页面操作和自动修复的逻辑。

base.py

# -*- coding: utf-8 -*-
# @Author  : blues_C
# @File    : base.py
# @Desc:import re
from utils.logger import log
from playwright.sync_api import Page, expect, Locatorclass BasePage:def __init__(self, page: Page):self.page = pagedef locator(self, selector: str) -> Locator:"""查找并返回元素"""element = self.page.locator(selector)if not element.is_visible():self.auto_repair()return elementdef click(self, selector: str):self.locator(selector).click()def fill(self, selector: str, input_value: str):self.locator(selector).fill(input_value)def auto_repair(self, scope_selector: str = "body",selector: str = "input, button, a, select, textarea, div, span, img, iframe, label, svg",filename="login_element.py"):### 自动修复逻辑：尝试重新定位页面上的所有相关元素，并更新我们的元素定位文件。### page_title = self.page.title()scope = self.page.locator(scope_selector)elements = scope.locator(selector).all()log.info(f"自愈元素: {selector} (共 {len(elements)} 个)")# 检查文件是否存在if os.path.exists(filename):# 读取现有文件内容，以便检查变量名with open(filename, "r") as file:lines = file.readlines()existing_variables = set()# 获取现有的变量名for line in lines:if "=" in line:variable_name = line.split("=")[0].strip()existing_variables.add(variable_name)# 打开文件，准备写入新内容with open(filename, "w") as file:file.write(f"# Existing variables from {page_title}\n\n")for element in elements:element_info = f"element='{element}', "start_index = element_info.find("selector=")if start_index != -1:selector_str = element_info[start_index + len("selector='"):]end_index = selector_str.find("'")if end_index != -1:selector_content = selector_str[:end_index]# 获取各个属性text = element.inner_text()value = element.get_attribute('value')element_id = element.get_attribute('id')element_class = element.get_attribute('class')element_name = element.get_attribute('name')element_type = element.get_attribute('type')element_placeholder = element.get_attribute('placeholder')# 检查属性是否为 None，并记录非 None 的属性log_info = f"element='{selector_content}', "if text != '':log_info += f"text='{text}'  "if value != '' and value is not None:log_info += f"[value='{value}']  "if element_id is not None:log_info += f"#{element_id}  "if element_class is not None:log_info += f"[class='{element_class}']  "if element_name is not None:log_info += f"[name='{element_name}']  "if element_type is not None:log_info += f"[type='{element_type}']  "if element_placeholder is not None:log_info += f"[placeholder='{element_placeholder}']"# 打印日志信息log.info(log_info)# 如果变量名已存在，替换现有的定义行if variable_name in existing_variables:file.write(f"# {log_info} (replaced)\n")if element.get_attribute('name') is not None:variable_name = element.get_attribute('name')variable_type = selector_contentfile.write(f"{variable_name} = '{variable_type}'\n\n")existing_variables.add(variable_name)elif element.get_attribute('type') is not None:variable_name = element.get_attribute('type')variable_type = selector_contentfile.write(f"{variable_name} = '{variable_type}'\n\n")existing_variables.add(variable_name)else:variable_type = selector_contentfile.write(f"'{variable_type}'\n\n")existing_variables.add(variable_name)else:# 如果文件不存在，则创建新文件并写入内容with open(filename, "w") as file:file.write(f"# {page_title}\n")for element in elements:element_info = f"element='{element}', "start_index = element_info.find("selector=")if start_index != -1:selector_str = element_info[start_index + len("selector='"):]end_index = selector_str.find("'")if end_index != -1:selector_content = selector_str[:end_index]text = element.inner_text()value = element.get_attribute('value')element_id = element.get_attribute('id')element_class = element.get_attribute('class')element_name = element.get_attribute('name')element_type = element.get_attribute('type')element_placeholder = element.get_attribute('placeholder')info = f"element='{selector_content}', "if text != '':info += f"text='{text}'  "if value != '' and value is not None:info += f"[value='{value}']  "if element_id is not None:info += f"#{element_id}  "if element_class is not None:info += f"[class='{element_class}']  "if element_name is not None:info += f"[name='{element_name}']  "if element_type is not None:info += f"[type='{element_type}']  "if element_placeholder is not None:info += f"[placeholder='{element_placeholder}']"log.info(info)file.write(f"# {info}\n")if element.get_attribute('name') is not None:variable_name = element.get_attribute('name')variable_type = selector_contentfile.write(f"{variable_name} = '{variable_type}'\n\n")elif element.get_attribute('type') is not None:variable_name = element.get_attribute('type')variable_type = selector_contentfile.write(f"{variable_name} = '{variable_type}'\n\n")else:variable_type = selector_contentfile.write(f"'{variable_type}'\n\n")

pytest fixture的使用

conftest.py

import pytest
from playwright.sync_api import sync_playwright@pytest.fixture(scope='session')
def browser():with sync_playwright() as p:browser = p.chromium.launch()yield browserbrowser.close()

测试用例编写

test_cases.py

import pytest
from common.base import BasePage
from playwright.sync_api import sync_playwrightdef test_auto_repair(browser):page = browser.new_page()page.goto('https://example.com')try:# 运行测试步骤BasePage(page).fill(login_element.username, 'username')BasePage(page).fill(login_element.password, 'password')BasePage(page).click(login_element.login)except Exception as e:pytest.fail(f'Test failed: {e}')BasePage(page).fill(login_element.username, 'username')BasePage(page).fill(login_element.password, 'password')BasePage(page).click(login_element.login)

元素定位文件

login_element.py 示例：

# 登录到 standard
# element='form >> input,button >> nth=0', #username  [class='form-control']  [name='username']  [type='text']  
username = 'form >> input,button >> nth=0'# element='form >> input,button >> nth=1', #password  [class='form-control']  [name='password']  [type='password']  
password = 'form >> input,button >> nth=1'# element='form >> input,button >> nth=2', #id-hidden-input  [name='credentialId']  [type='hidden']  
credentialId = 'form >> input,button >> nth=2'# element='form >> input,button >> nth=3', [value='登录']  #kc-login  [class='btn btn-primary btn-block btn-lg']  [name='login']  [type='submit']  
login = 'form >> input,button >> nth=3'