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
1
2

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, Locator

class BasePage:
    def __init__(self, page: Page):
        self.page = page
        
    def 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 element
        
    def 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_content
	                            file.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_content
	                            file.write(f"{variable_name} = '{variable_type}'\n\n")
	                            existing_variables.add(variable_name)
	                        else:
	                            variable_type = selector_content
	                            file.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_content
	                            file.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_content
	                            file.write(f"{variable_name} = '{variable_type}'\n\n")
	                        else:
	                            variable_type = selector_content
	                            file.write(f"'{variable_type}'\n\n")
    
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159

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 browser
        browser.close()
1
2
3
4
5
6
7
8
9

测试用例编写

test_cases.py

import pytest
from common.base import BasePage
from playwright.sync_api import sync_playwright

def 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)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

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'
1
2
3
4
5
6
7
8
9
10
11
12

总结

本文展示了如何使用Playwright的Locator结合pytest的自动化测试框架来实现元素的自动定位和修复。通过封装页面操作和自动修复逻辑到BasePage类中，我们可以提高测试的稳定性和可维护性。同时，使用pytest的fixture来管理浏览器的生命周期，使得测试更加简洁。

通过上述方法，我们能够确保即使在面对复杂的页面元素变化时，我们的自动化测试也能够适应并成功执行，从而提高测试的覆盖率和准确性。