While creating WebDriver object we use, for example
WebDriver driver = new ChromeDriver();
Why it cannot be as below,
WebDriver driver = new WebDriver();
Just wanted to know the reason for this.
WebDriver is an interface, we can not create an instance of it.
where as ChromeDriver is a class which extends RemoteWebDriver class.
and RemoteWebDriver class basically implements WebDriver Interface.
so writing new WebDriver(); is not valid in Java, since we can not create object of Interface. This will result in compile time error.
Internal Implementation of WebDriver Interface :
public interface WebDriver extends SearchContext{
void get(String url);
String getCurrentUrl();
// and so on....
}
all the methods which are present above are overridden in RemoteWebDriver
Related
I'd like to execute Selenium Grid tests using Maven like this:
mvn verify-Dtest=BaseTest -Dprop.selenium.server.url=http://localhost:4444/wd/hub
-Dprop.browser=chrome
-Dprop.version=80.0.3987.106
I inject ChromeDriver into Test constructor using JUnit5 ParameterResolver interface
#ExtendWith(ChromeRemoteWebDriverParameterResolver.class)
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class MultiBrowserDemoTest {
RemoteWebDriver driver;
public MultiBrowserDemoTest(RemoteDriver driver) {
this.driver = driver.getDriver();
}
#SneakyThrows
#Test
public void testGrid() {
driver.get("https://www.google.com/");
WebElement search = driver.findElement(By.name("q"));
search.sendKeys("JUnit5 extensions");
search.submit();
}
#AfterAll()
void tearDown() {
driver.quit();
}
}
It works fine. But I can't see how to implement multi-browser test execution.
Let's say, I want to add multiple browsers -Dprop.browser=chrome, firefox, opera, ie11
I created multiple classes implementing ParameterResolver Interface. But JUnit5 does not let me inject them all into my Test Class. It does not create new instances of Test class either.
I tried to use TestInstanceFactory to create new Instances of my Test class and apply separate implementation of ParameterResolver interface, but it did not work for me.
End Result: I can run the same test in multiple browsers in parallel using Selenium Grid and only one Test Class that I will be able to instantiate multiple times with separate webdriver.
If I understood your scenario correctly, what you are asking for is support for what we call "parameterized containers" (i.e., something analogous to #ParameterizedTest but at the class level), which does not exist yet in JUnit Jupiter.
See JUnit Jupiter issues #871 and #878 for details.
RemoteWebdriver implements Webdriver interface then why don't we up-cast to RemoteWebdriver instead of Webdriver while creating object of any browser driver?
By definition upcasting is
a variable of Parent class refers to the object of Child class
In other words if class A is parent, then class B extends A is a child. Upcasting would be:
B b = new B();
A a = b; // upcasting
But relationship between RemoteWebDriver and WebDriver is not of a parent/child:
RemoteWebDriver implements WebDriver
Hence there's no upcasting here. And the question is different:
why don't we declare concrete type RemoteWebDriver instead of WebDriver while creating object of any browser driver
the reasons are same as when answering a more generic question: Why should the interface for a Java class be preferred?. And really: if Selenium developers removed/deprecated RemoteWebDriver would you want to change your tests?
BTW: here's a case of actual upcasting to RemoteWebDriver:
ChromeDriver driver = new ChromeDriver(); // ChromeDriver extends RemoteWebDriver
RemoteWebDriver remoteDriver = driver;
Also the following is valid, although hard to find a reason why you'd want to do it:
WebDriver driver = new ChromeDriver();
RemoteWebDriver remoteDriver = (RemoteWebDriver) driver;
One use case I've seen is when people want to use some other interface implemented by RemoteWebDriver (i.e. not WebDriver, but say TakesScreenshot). But then it's better to cast to that interface directly:
WebDriver driver = new ChromeDriver();
TakesScreenshot ts = (TakesScreenshot) driver;
ts.getScreenshotAs(...);
My automation framework is using selenium + TestNG + PageObject model.
Structure :
My Testng class / test case :
nullpointer error
How can i pass the driver instance into my page objects?
I can see you are declaring a new instance of WebDriver inside the #BeforeTest method. You need to use the WebDriver instance that you declared outside the #BeforeTest i.e. you have already declared
static WebDriver driver;
Use the same driver inside your #BeforeTest. So inside the before method, instead of doing WebDriver driver = new FirefoxDriver(); write like driver = new FirefoxDriver();
Do same for other browser types (ie, safari, chrome).
And for you page object classes, you can do something as follows:
public class TaxPage {
public static WebDriver driver;
public TaxPage(WebDriver driver) {
this.driver = driver;
}
}
Create a class like below and pass WebDriver in parametrize constructor and Call driver like Page.driver whenever you need it
public class Page
{
public static WebDriver driver;
public Page(WebDriver driver)
{
Page.driver = driver;
}
}
Hope it will help you :)
How to implement the DriverSetup class in Selenium Webdriver framework..
Currently I am launching driver in #BeforeClass for each testng test class, please let me know if how can I implement the common driverLaunch/driverSetup class for all test
Thanks in Advance..
Did u mean a common setup for all classes? If so create a base class and extend it in every test class. In Base class have #BeforeClass to do the required.
It would be somewhat like:
public class BaseClass {
WebDriver driver;
#BeforeClass
public void setUp() {
driver = new FirefoxDriver(); // or any driver u want, or based on requirement create a if else scenario
}
}
And in Testclass do like:
public class TestClass extends BaseClass {
// your class body with tests here
}
So whenever u run ur tests through testng it will call the setUp method in BaseClass and setup browser for u.
Init your WebDriver in #BeforeTest or in #BeforeSuite and close it in #AfterTest or #AfterSuite. So in this case every test method will get run in the same browser.
im a newbie in c# and selenium.
Im trying to create an element extension to mouseover an element.
I've got the following:
public static void mouseoverElement(this IWebElement element, IWebDriver driver)
{
Actions actions = new Actions(driver);
actions.MoveToElement(element).Perform();
}
And this would be called from another class
public MLinks mouseOverCandidate()
{
candidateMenu.mouseoverElement(driver);
return this;
}
And this is where i will call from the test:
new HomePage(driver, server)
.MainLinks.mouseOverCandidate();
I will always get this which i don't quite understand. I've already got a driver set. Anyone can help me out on this? thanks
System.ArgumentException : The IWebDriver object must implement or wrap a driver that implements IHasInputDevices.
The method mouseoverElement is taking an IWebDriver, which is an interface.
The concrete driver class implements this interface, as well as the other interface IHasInputDevices.
So you need to pass in the concrete class, so that it can expose IHasInputDevices, as well as IWebDriver
Note that you will also get this error if the WebDriver you pass in is null.