在不同的类中访问@BeforeTest和@AfterClass（TestNG）中的变量？

Question

I am writing some selenium automated UI tests for my company using Java and the TestNG framework. I am defining the driver in a Base class, and I want to actually initialize the driver in an @BeforeTest and quit it in a @AfterTest method. What is the Java way to do that, assuming they are in different classes? I know how to make it work in the same class, but not over separate classes. Here is my Base.java file:

public class Base {

        public static WebDriver driver = null;
        public WebDriver getDriver() {
            driver = new ChromeDriver();
            return driver;
        }
}

Now, I want to have a separate Setup class and a separate Teardown class. If I was going to define all of this in the same @Test , I would do it this way:

@Test
public void testOne() {

    Base b = new Base();
    WebDriver driver = b.getDriver();

    // Do test-y things here. 

    driver.quit();
}

How would I set this up? Trying to learn the right way to do this, and not hack something together. I can also provide more information if needed. Thanks!

Answer 1

Use inheritance.

public class TestBase {

    protected WebDriver driver;

    @BeforeClass
    public void setUp(){
        System.out.println("I am in setUp method.");

        //WebDriver instantiation etc.
        System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");
        ChromeOptions options = new ChromeOptions();
        options.addArguments("--start-maximized", "--disable-cache");
        driver = new ChromeDriver(options);
        driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
    }

    @AfterClass
    public void tearDown(){
        System.out.println("I am in tearDown method.");

        //You can clean up after tests.
        driver.close();
    }
}

And then inheritance can be used. Pay attention to the extends keyword:

public class ParticularTest extends TestBase {

   @Test
   public void testMethod() {
       System.out.println("I am in testMethod.");

       //Your driver from TestBase is accessible here.
       //Your assertions come here.
   }
}

Later on you can just execute ParticularTest.java . Output:

I am in setUp method.
I am in testMethod.
I am in tearDown method.

Answer 2

I would suggest that you please DONOT resort to this mechanism of instantiating webdrivers in your tests. @BeforeTest by definition is expected to be invoked ONLY ONCE per <test> tag. So if your TestNG suite xml file has something like this

<test name="MyTests">
    <classes>
        <class name="com.foo.Test1"/>
        <class name="com.foo.Test2"/>
    </classes>
</test>

and if both com.foo.Test1 and com.foo.Test2 extend your TestBase class, then the @Test methods within your com.foo.Test2 class are bound to hit a NullPointerException when accessing your driver object because your @BeforeTest annotated setup() method within TestBase will be executed only once (for Test1 ) and it will NOT be executed for Test since both the classes extend from the same base class.

I would suggest that you please resort to something like this (this is my blog) to do web driver instantiations.