Selenium source code read through · 9 | desiredcapabilities class analysis

1 Source directory

selenium/webdriver/common/desired_capabilities.py

2 Function description

According to the DesiredCapabilities Parameters , To decide which machine to distribute the test code to node Test on ;
Supplementary knowledge ： We need to understand selenium grid;

3 Selenium Grid Introduce

3.1 What is it? ？

Selenium Part of the kit , It is designed to run multiple test cases in parallel in different browsers 、 Operating system and machine ;

Selenium Grid The main use of master-slaves (or hub-nodes) idea , It's a master/hub And multiple based on master/hub Registered child nodes slaves/nodes;

stay master Based on different browsers / When the system runs test cases ,master Will be distributed to the appropriate node function ;

3.2 When to use ？

At the same time in different browsers 、 Run tests on the operating system and the machine ;

For compatibility testing ;

Reduce running time .

3.3 How to use it? ？

start-up Selenium Grid In three ways , A direct command line , Another way to use JSON The configuration file , The last one docker start-up .

3.3.1 Command line start

Simply put the next step , Please refer to other materials for details , function hub The machine is A, function node The machine is B.

To configure Java Environmental Science ;

browser ;

Browser corresponding driver;

download selenium server, take selenium-server-standalone-3.141.59.jar, machine A And machines B On ;

machine A Open the command line on the , Get into selenium server Under the table of contents , function ：

ava -jar selenium-server-standalone-3.141.59.jar -role hub -port 5566

Browser input http://localhost:5566/grid/console ;
machine B Open the command line on the , Get into selenium server Under the table of contents , function ：

java -jar selenium-server-standalone-3.141.59.jar -role node -hub http://192.168.1.100:5566/grid/register/ -port 5577

Refresh http://localhost:5566/grid/console ;

Run the test script , Will see in the machine B It's on Chrome browser , And will run test cases .

3.3.2 Json Profile startup

establish hub Of Json The configuration file ;

{
  "port": 4444,
  "newSessionWaitTimeout": -1,
  "servlets" : [],
  "withoutServlets": [],
  "custom": {},
  "capabilityMatcher": "org.openqa.grid.internal.utils.DefaultCapabilityMatcher",
  "registry": "org.openqa.grid.internal.DefaultGridRegistry",
  "throwOnCapabilityNotPresent": true,
  "cleanUpCycle": 5000,
  "role": "hub",
  "debug": false,
  "browserTimeout": 0,
  "timeout": 1800
}

The above code is saved as hub_config.json file , Put it in machine A Shanghe selenium server In the same way ;
establish nodes Of Json The configuration file ;

{
  "capabilities":
  [
    {
      "browserName": "firefox",
      "marionette": true,
      "maxInstances": 5,
      "seleniumProtocol": "WebDriver"
    },
    {
      "browserName": "chrome",
      "maxInstances": 5,
      "seleniumProtocol": "WebDriver"
    },
    {
      "browserName": "internet explorer",
      "platform": "WINDOWS",
      "maxInstances": 1,
      "seleniumProtocol": "WebDriver"
    },
    {
      "browserName": "safari",
      "technologyPreview": false,
      "platform": "MAC",
      "maxInstances": 1,
      "seleniumProtocol": "WebDriver"
    }
  ],
  "proxy": "org.openqa.grid.selenium.proxy.DefaultRemoteProxy",
  "maxSession": 5,
  "port": -1,
  "register": true,
  "registerCycle": 5000,
  "hub": "http:// This is the machine A Of ip:4444",
  "nodeStatusCheckTimeout": 5000,
  "nodePolling": 5000,
  "role": "node",
  "unregisterIfStillDownAfter": 60000,
  "downPollingLimit": 2,
  "debug": false,
  "servlets" : [],
  "withoutServlets": [],
  "custom": {}
}

Save as node_config.json file , Put it on the machine B Shanghe selenium server In the same way ;

machine A, function ：

java -jar selenium-server-standalone-3.141.59.jar -role hub -hubConfig hub_config.json

machine B, function ：

java -jar selenium-server-standalone-3.141.59.jar -role node -nodeConfig node_config.json

3.3.3 docker start-up

install docker;

start-up hub：

docker run -d -p 4444:4444 --name selenium-hub selenium/hub

start-up node, such as chrome browser ;

docker run -d --link selenium-hub:hub selenium/node-chrome

visit ：http://localhost:4444/grid/console;

Run multiple node：

docker run -d --link selenium-hub:hub selenium/node-chrome

close docker-grid The order of ：

docker stop $(docker ps -a -q), docker rm $(docker ps -a -q)

Be careful , In particular ： About Selenium Grid Content reference and https://blog.csdn.net/lb245557472/article/details/91966770

4 Part of the source code description

class DesiredCapabilities(object):
    """
    Set of default supported desired capabilities.

    Use this as a starting point for creating a desired capabilities object for
    requesting remote webdrivers for connecting to selenium server or selenium grid.

    Usage Example::

        from selenium import webdriver

        selenium_grid_url = "http://198.0.0.1:4444/wd/hub"

        # Create a desired capabilities object as a starting point.
        capabilities = DesiredCapabilities.FIREFOX.copy()
        capabilities['platform'] = "WINDOWS"
        capabilities['version'] = "10"

        # Instantiate an instance of Remote WebDriver with the desired capabilities.
        driver = webdriver.Remote(desired_capabilities=capabilities,
                                  command_executor=selenium_grid_url)

    Note: Always use '.copy()' on the DesiredCapabilities object to avoid the side
    effects of altering the Global class instance.

    """

    FIREFOX = {
        "browserName": "firefox",
        "marionette": True,
        "acceptInsecureCerts": True,
    }

    INTERNETEXPLORER = {
        "browserName": "internet explorer",
        "version": "",
        "platform": "WINDOWS",
    }

    EDGE = {
        "browserName": "MicrosoftEdge",
        "version": "",
        "platform": "WINDOWS"
    }
#  The rest of the source code is omitted 

From source code , The following describes the browser system ：

browserName： browser 
version： Operating system version 
platform： operating system 

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