Selenium "no such session" error on TestNG testing.xml

Question

I am trying to run a simple test with crossbrowsers using testing.xml of TestNG. Script runs fine on the first run which is Chrome. But gives "no such session" error on the firefox test beginning.

I simplified the codes to make it easy to read. I hope it helps.

Here's my TestNG testing.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="DefaultSuite" thread-count="1" parallel="tests">
    <test name="ChromeTest">
        <parameter name="browser" value="Chrome" />
        <classes>
            <class name="loginTest">
            </class>
        </classes>
    </test>

    <test name="FirefoxTest">
        <parameter name="browser" value="Firefox" />
        <classes>
            <class name="loginTest">
            </class>
        </classes>
    </test>
</suite>

And here's my code

public class loginTest {
    private static WebDriver driver;

    @BeforeTest
    @Parameters("browser")
    public void testSetup(String browser) throws Exception {
        //Check if parameter passed from TestNG is 'firefox'
        if(browser.equalsIgnoreCase("firefox")){
            driver = webBrowsers.browserAl("Firefox");
        }
        //Check if parameter passed as 'chrome'
        else if(browser.equalsIgnoreCase("chrome")){
            driver = webBrowsers.browserAl("Chrome");
        }
        else{
            //If no browser passed throw exception
            throw new Exception("Browser is not correct");
        }
    }

    @Test(priority=0)
    public void LoginTest(){
        driver.get("http://www.hurriyet.com.tr/");
    }

    @AfterTest
    public void kapat() {
        webBrowsers.closeDriver();
    }
}

and finally my webBrowsers.class

public class webBrowsers {
    private static WebDriver driver = null;
    private static String browserName;

    public static WebDriver browserAl(String browserName) {

        if (browserName.equals("Firefox")) {
            if (driver == null) {
                System.setProperty("webdriver.gecko.driver","./drivers/geckodriver.exe");
                driver = new FirefoxDriver();
            }
        } else if (browserName.equals("Edge")) {
            if (driver == null) {
                System.setProperty("webdriver.edge.driver", "./drivers/MicrosoftWebDriver.exe");
                driver = new EdgeDriver();
            }
        } else if (browserName.equals("Chrome")) {
            if (driver == null) {
                System.setProperty("webdriver.chrome.driver","./drivers/chromedriver.exe");
                driver = new ChromeDriver();
            }
        }
        driver.manage().window().maximize();
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
        driver.manage().timeouts().pageLoadTimeout(60, TimeUnit.SECONDS);
        return driver;
    }

    public static void closeDriver() {
        driver.close();
    }
}

Answer 1

问题出在班级webBrowsers。您正在使用静态webdriver实例。因此，对于第一个<test>执行，driver实例将不为null，并且它将被正确实例化。但是当您执行第二个<test>标记时，条件driver == null将为false，并且您最终会获得对为先前<test>标记创建的webdriver对象的引用。更糟糕的是，你有一个@AfterTest方法来清理驱动程序实例。因此，您现在基本上使用有效的webdriver实例，但已打开的会话已被清除。

最终结果：您的错误。

这是一个清理过的代码版本，可以解决这个问题。

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.edge.EdgeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;

import java.util.concurrent.TimeUnit;

public class WebBrowsers {
    public static WebDriver browserAl(String browserName) {
        WebDriver driver = null;

        if (browserName.equals("Firefox")) {
            System.setProperty("webdriver.gecko.driver", "./drivers/geckodriver.exe");
            driver = new FirefoxDriver();
        } else if (browserName.equals("Edge")) {
            System.setProperty("webdriver.edge.driver", "./drivers/MicrosoftWebDriver.exe");
            driver = new EdgeDriver();
        } else if (browserName.equals("Chrome")) {
            System.setProperty("webdriver.chrome.driver", "./drivers/chromedriver.exe");
            driver = new ChromeDriver();
        }
        driver.manage().window().maximize();
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
        driver.manage().timeouts().pageLoadTimeout(60, TimeUnit.SECONDS);
        return driver;
    }

    public static void closeDriver(WebDriver driver) {
        if (driver != null) {
            driver.quit();
        }
    }
}

以下是您的测试类的外观

import org.openqa.selenium.WebDriver;
import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Parameters;
import org.testng.annotations.Test;

public class LoginTest {
    private WebDriver driver;

    @BeforeTest
    @Parameters("browser")
    public void testSetup(String browser) throws Exception {
        //Check if parameter passed from TestNG is 'firefox'
        if (browser.equalsIgnoreCase("firefox")) {
            driver = WebBrowsers.browserAl("Firefox");
        }
        //Check if parameter passed as 'chrome'
        else if (browser.equalsIgnoreCase("chrome")) {
            driver = WebBrowsers.browserAl("Chrome");
        } else {
            //If no browser passed throw exception
            throw new Exception("Browser is not correct");
        }
    }

    @Test
    public void loginTest() {
        driver.get("http://www.hurriyet.com.tr/");
    }

    @AfterTest
    public void kapat() {
        WebBrowsers.closeDriver(driver);
    }
}