Selenium Web Driver Questions & Answers

Question 1:

What is Selenium 2.0? I have heard this buzz word many times.

Answer

Selenium 2.0 is consolidation of two web testing tools – Selenium RC and WebDriver, which claims to give best of both words – Selenium and WebDriver. Selenium 2.0 was officially released only of late.

Question 2:

Why are two tools being combined as Selenium 2.0, what’s the gain?

Answer

Selenium 2.0 promises to give much cleaner API then Selenium RC and at the same time not being restricted by java script Security restriction like same origin policy, which have been haunting Selenium from long. Selenium 2.0 also does not warrant you to use Selenium Server.

Question 3:

So everyone is going to use Selenium 2.0?

Answer

Well no, for example if you are using Selenium Perl client driver than there is no similar offering from Selenium 2.0 and you would have to stick to Selenium 1.0 till there is similar library available for Selenium 2.0

Question 4:

So how do I specify my browser configurations with Selenium 2.0?

Answer

Selenium 2.0 offers following browser/mobile configuration –

·         AndroidDriver,

·         ChromeDriver,

·         EventFiringWebDriver,

·         FirefoxDriver,

·         HtmlUnitDriver,

·         InternetExplorerDriver,

·         IPhoneDriver,

·         IPhoneSimulatorDriver,

·         RemoteWebDriver

And all of them have been implemented from interface WebDriver. To be able to use any of these drivers you need to instantiate their corresponding class.

Question 5:

How is Selenium 2.0 configuration different than Selenium 1.0?

Answer

In case of Selenium 1.0 you need Selenium jar file pertaining to one library for example in case of java you need java client driver and also Selenium server jar file. While with Selenium 2.0 you need language binding (i.e. java, C# etc) and Selenium server jar if you are using Remote Control or Remote WebDriver.

Question 6:

Can you show me one code example of setting Selenium 2.0?

Answer

Here is java example of initializing firefox driver and using Google Search engine –

protected WebDriver webDriver;

//@BeforeClass(alwaysRun=true)

public void startDriver(){

webDriver = new FirefoxDriver();

// Get Google search page and perform search on term “Test”

webDriver.get("http://www.google.com");

webDriver.findElement(By.name("q")).sendKeys("Test");

webDriver.findElement(By.name(“btnG”)).click();

Question 7:

Which web driver implementation is fastest?

Answer

HTMLUnitDriver. Simple reason is HTMLUnitDriver does not execute tests on browser but plain http request – response which is far quick than launching a browser and executing tests. But then you may like to execute tests on a real browser than something running behind the scenes

Question 8:

What all different element locators are available with Selenium 2.0?

Answer

Selenium 2.0 uses same set of locators which are used by Selenium 1.0 – id, name, css, XPath but how Selenium 2.0 accesses them is different. In case of Selenium 1.0 you don’t have to specify a different method  for each locator while in case of Selenium 2.0 there is a different method available to use a different element locator. Selenium 2.0 uses following method to access elements with id, name, css and XPath locator –

driver.findElement(By.id("HTMLid"));

driver.findElement(By.name("HTMLname"));

driver.findElement(By.cssSelector("cssLocator"));

driver.findElement(By.xpath("XPathLocator));

Question 9:

How do I submit a form using Selenium?

Answer

You can use “submit” method on element to submit form –

element.submit();

Alternatively you can use click method on the element which does form submission.

Question 10:

Can I simulate pressing key board keys using Selenium 2.0?

Answer

You can use “sendKeys” command to simulate key board keys as –

element.sendKeys(" and some", Keys.ARROW_UP);

You can also use “sendKeys” to type in text box as –

HTMLelement.sendKeys("testData");

Question 11

How do I clear content of a text box in Selenium 2.0

Answer

You can use “clear” method on text box element to clear its content –

textBoxElement.clear();

Question 12:

How do I select a drop down value using Selenium2.0?

Answer

To select a drop down value, you first need to get the select element using one of element locator and then you can select element using visible text –

Select selectElement = new Select(driver.findElement(By.cssSelector("cssSelector")));

selectElement.selectByVisibleText("India");

Question 13:

What are offering to deal with popup windows while using Selenium 2.0?

Answer

You can use “switchTo” window method to switch to a window using window name. There is also one method “getWindowHandles” which could be used to find all Window handles and subsequently bring control on desired window using window handle –

webDriver.switchTo().window("windowName");

for (String handle : driver.getWindowHandles()) {

driver.switchTo().window(handle);

}

Question 14:

How about handling frames using Selenium 2.0?

Answer

You can use “switchTo” frame method to bring control on an HTML frame –

driver.switchTo().frame("frameName");

You can also use index number to specify a frame –

driver.switchTo().frame("parentFrame.4.frameName");

This would bring control on frame named – “frameName” of the 4^th sub frame names “parentFrame”

Question 15:

Can I navigate back and forth in a browser in Selenium 2.0?

Answer

You can use Navigate interface to go back and forth in a page. Navigate method of WebDriver interface returns instance of Navigation. Navigate interface has methods to move back, forward as well as to refresh a page –

driver.navigate().forward();

driver.navigate().back();

driver.navigate().refresh();

Question 16:

What is the order of fastest browser implementation for WebDriver?

Answer

HTMLUnitDriver is the fastest browser implementation as it does not involves interaction with a browser, This is followed by Firefox driver and then IE driver which is slower than FF driver and runs only on Windows.

 Question 17:

Is it possible to use Selenium RC API with Selenium 2.0?

Answer

You can emulate Selenium 1.0 API with Selenium 2.0 but not all of Selenium 1.0 methods are supported. To achieve this you need to get Selenium instance from WebDriver and use Selenium methods. Method executions might also be slower while simulating Selenium 1.0 with in Selenium 2.0

 Question 18:

Can you show me one example of using Selenium 1.0 in Selenium 2.0?

Answer

Code Sample:

// Create web driver instance

WebDriver driver = new FirefoxDriver();

// App URL

String appUrl = "http://www.google.com";

// Get Selenium instance

Selenium selenium = new WebDriverBackedSelenium(driver, appUrl);

// Tests using selenium

selenium.open(appURL);

selenium.type("name=q", "testData");

selenium.click("name=btnG");

// Get back the WebDriver instance

WebDriver driverInstance = ((WebDriverBackedSelenium) selenium).getUnderlyingWebDriver();

Question 19:

I had support of lots of browsers while using Selenium 1.0 and it seems lacking with Selenium 2.0, for example how do I use < awesome> browser while using Selenium 2.0?

Answer

There is a class called Capabilities which lets you inject new Capabilities in WebDriver. This class can be used to set testing browser as Safari –

//Instantiate Capabilities

Capabilities capabilities = new DesiredCapabilities()

//Set browser name

capabilities.setBrowserName("this awesome browser");

//Get your browser execution capabilities

CommandExecutor executor = new SeleneseCommandExecutor("http:localhost:4444/", "http://www.google.com/", capabilities);

//Setup driver instance with desired Capabilities

WebDriver driver = new RemoteWebDriver(executor, capabilities);

Question 20:

Are there any limitations while injecting capabilities in WebDriver to perform tests on a browser which is not supported by WebDriver?

Answer

Major limitation of injecting Capabilities is that “fundElement” command may not work as expected. This is because WebDriver uses Selenium Core to make “Capability injection” work which is limited by java script security policies.

Question 21:

Can I change User-Agent while using FF browser? I want to execute my tests with a specific User-Agent setting.

Answer

You can create FF profile and add additional Preferences to it. Then this profile could be passed to Firefox driver while creating instance of Firefox –

FirefoxProfile profile = new FirefoxProfile();

profile.addAdditionalPreference("general.useragent.override", "User Agent String");

WebDriver driver = new FirefoxDriver(profile);

Question 22:

Is there any difference in XPath implementation in different WebDriver implementations?

Answer

Since not all browsers (like IE) have support for native XPath, WebDriver provides its own implementation for XPath for such browsers. In case of HTMLUnitDriver and IEDriver, html tags and attributes names are considered lower cased while in case of FF driver they are considered case in-sensitive.

Question 23:

My application uses ajax highly and my tests are suffering from time outs while using Selenium 2.0L.

Answer

You can state WebDriver to implicitly wait for presence of Element if they are not available instantly. By default this setting is set to 0. Once set, this value stays till the life span of WebDriver object. Following example would wait for 60 seconds before throwing ElementNotFound exception –

WebDriver driver = new FirefoxDriver();

driver.manage().timeouts().implicitlyWait(60, TimeUnit.SECONDS);

WebElement element = driver.findElement(By.id("elementID"));

Question 24:

What if I don’t want to use implicit wait and want to wait only for presence of certain elements?

Answer

You can use explicit wait in this situation to wait for presence of certain element before continuing with test execution. You can use “WebDriverWait” and “ExpectedCondition” to achieve this –

WebDriver driver = new FirefoxDriver();

WebElement myDynamicElement = (new WebDriverWait(driver, 60)).until(new ExpectedCondition<WebElement>(){

@Override

public WebElement apply(WebDriver d) {

return d.findElement(By.id("myDynamicElement"));

}});

This is going to wait up to 60 seconds before throwing ElementNotFound exception.

Question 25:

What is RemoteWebDriver? When would I have to use it?

Answer

RemoteWebDriver is needed when you want to use HTMLUnitDriver. Since HTMLUnitDriver runs in memory, you would not see a browser getting launched –

// Create HTMLUnitDriver instance

WebDriver driver = new HtmlUnitDriver();

// Launch Yahoo.com

driver.get("http://www.yahoo.com");

Question 26:

What all languages available to be used with WebDriver?

Answer

Java and C# are on the forefront of WebDriver languages. Support is also available for Python and Ruby. There is also one java script library available for Friefox.

Question 27:

How do I handle java script alert using WebDriver?

Answer

WebDriver would support handling js alerts using Alert interface.

// Bring control on already opened alert

Alert alert = driver.switchTo().alert();

// Get the text of the alert or prompt

alert.getText();

// Click ok on alert

alert.accept();

Question 28:

Could I safely execute multiple instances of WebDriver implementations?

Answer

As far as HTMLUnitDriver and FF drivers are concerned, each instance would be independent of other. In case of IE driver there could be only one instance of IE driver running on Windows. If you want to execute more than one instance of IE driver then you should consider using RemoteWebDriver and virtual machines.

Question 29:

Is it possible to interact with hidden elements using WebDriver?

Answer

Since WebDriver tries to exercise browser as closely as real users would, hence simple answer is No, But you can use java script execution capabilities to interact with hidden elements.

Question 30:

I have all my tests written in Selenium 1.0 (Selenium RC), why should I migrate to Selenium 2.0 (WebDriver)?

Answer

Because –

·         WebDriver has more compact and object oriented API than Selenium 1.0

·         WebDriver simulates user behaviour more closely than Selenium 1.0, for example if a text box is disabled WebDriver would not be able to type text in it while Selenium 1.0 would be

·         WebDriver is supported by Browser vendor themselves i.e. FF, Opera, Chrome etc

Question 31:

My XPath and CSS locators don’t always work with Selenium 2.0, but they used to with Selenium 1.0L.

Answer

In case of XPath, it is because WebDriver uses native browser methods unless it is not available. And this cause complex XPath to be broken. In case of Selenium 1.0 css selectors are implemented using Sizzle Library and not all the capabilities like “contains” are available to be used with Selenium 2.0

Question 32:

How do I execute Java Script in Selenium 2.0?

Answer

You need to use JavaScriptExecutor to execute java script in Selenium 2.0, For example if you want to find tag name of an element using Selenium 2.0 then you can execute java script as following –

WebElement element = driver.findElement(By.id("elementLocator"));

String name = (String) ((JavascriptExecutor) driver).executeScript(

"return arguments[0].tagName", element);

Question 33:

Why does not my java script execution return any value?

Answer

This might happen when you forget to add “return“ keyword while executing java script. Notice the “return” keyword in following statement –

((JavascriptExecutor) driver).executeScript("return window.title;");

Question 34:

Are there any limitations from operating systems while using WebDriver?

Answer

While HTMLUnitDriver, FF Driver and Chrome Driver could be used on all operating systems, IE Driver could be used only with Windows.

Question 35:

Give me architectural overview of WebDriver.

Answer

WebDriver tries to simulate real user interaction as much as possible. This is the reason why WebDriver does not have “fireEvent” method and “getText” returns the text as a real user would see it. WebDriver implementation for a browser is driven by the language which is best to driver it. In case of FF best fit languages are Javascript in an XPCOM component and in IE it is C++ using IE automation. Now the implementation which is available to user is a thin wrapper around the implementation and user need not know about implementation.

Question 36:

What is Remote WebDriver Server?

Answer

Remote WebDriver Server has two components – client and server. Client is WebDriver while Server is java servlet. Once you have downloaded selenium-server-standalone-.jar file you can start it from command line as –

        java -jar selenium-server-standalone-<version-number>.jar

Question 37:

Is there a way to start Remote WebDriver Server from my code?

Answer

First add Remote WebDriver jar in your class path. You also need another server called “Jetty” to use it. You can start sever as following –

WebAppContext context = new WebAppContext();

context.setContextPath("");

context.setWar(new File("."));

server.addHandler(context);

context.addServlet(DriverServlet.class, "/wd/*");

SelectChannelConnector connector = new SelectChannelConnector();

connector.setPort(3001);

server.addConnector(connector);

server.start();

Question 38:

But what are the advantages of using Remote WebDriver over WebDriver?

Answer

You can use Remote WebDriver when –

·         When you want to execute tests on a browser not available to you locally

·         Introduction to extra latency to tests

But there is one disadvantage of using Remote WebDriver that you would need external servlet container.

Question 39:

Can you show me code example of using Remote WebDriver?

Answer

// Any driver could be used for test

DesiredCapabilities capabilities = new DesiredCapabilities();

// Enable javascript support

capabilities.setJavascriptEnabled(true);

// Get driver handle

WebDriver driver = new RemoteWebDriver(capabilities);

// Launch the app

driver.get("http://www.google.com");

Question 40:

What are the modes of Remote WebDriver

Answer

Remote WebDriver has two modes of operations –

Client Mode: This is where language bindings connect to remote instance. FF drive and RemoteWebDriver clients work this way.

Server Mode: In this mode language bindings set up the server. ChromeDriver works this way.

Question 41:

What Design Patterns could be used while using Selenium 2.0?

Answer

These three Design Patterns are very popular while writing Selenium 2.0 tests –

·         Page Objects – which abstracts UI of web page

·         Domain Specific Language – which tries to write tests which could be understood by a normal user having no technical knowledge

·         Bot Style Tests – it follows “command-like” test scripting

Question 42:

So do I need to follow these Design patterns while writing my tests?

Answer

Not at all, these Design Patterns are considered best practices and you can write you tests without following any of those Design Patterns, or you may follow a Design Pattern which suites your needs most.

Question 43:

Is there a way to enable java script while using HTMLUnitDriver?

Answer

Use this –

HtmlUnitDriver driver = new HtmlUnitDriver();

driver.setJavascriptEnabled(true);

or this –

HtmlUnitDriver driver = new HtmlUnitDriver(true);

Question 44:

Is it possible to emulate a browser with HTMLUnitDriver?

Answer

You can emulate browser while using HTMLUnitDriver but it is not recommended as applications are coded irrespective of browser you use. You could emulate Firefox 3 browser with HTMLUnitDriver as –

HtmlUnitDriver driver = new HtmlUnitDriver(BrowserVersion.FIREFOX_3);

Or you can inject desired capabilities while instantiating HTMLUnitDriver as –

HtmlUnitDriver driver = new HtmlUnitDriver(capabilities);

Question 45:

How do I use iPhone Driver?

Answer

You should start iPhone SDK and build iPhone driver. Down load iPhone development tools and provision profile. Now iPhone driver can connect through HTTP to the iphone simulator. You can also run simulator on another machine in your network and WebDriver could connect to it remotely.

Question 46:

Is it possible to convert Selenium IDE test to WebDriver test?

Answer

For now there is no formatter available to convert Selenium IDE tests to corresponding WebDriver tests, hence simple answer is No. Yes WebDriver style of code can be generated from Selenium IDE

Question 47:

Can WebDriver handle UntrustedSSLCertificates?

Answer

This feature is currently supported in Firefox browser and is awaiting implementation in IE and Chrome drivers.

Question 48:

Can I carry out multiple operations at once while using WebDriver?

Answer

You can use Builder pattern to achieve this. For example if you want to move an element from one place to another you can use this –

Actions builder = new Actions(driver);

Action dragAndDrop = builder.clickAndHold(element)

.moveToElement(otherElement)

.release(otherElement)

.build();

dragAndDrop.perform();

Question 49:

How do I simulate keyboard keys using WebDriver?

Answer

There is a KeyBoard interface which has three methods to support keyboard interaction –

• sendKeys(CharSequence)- Sends character sequence
• pressKey(Keys keyToPress) - Sends a key press without releasing it.
• releaseKey(Keys keyToRelease) - Releases a modifier key

Question 50:

What about Mouse Interaction?

Answer

Mouse interface lets you carry out following operations –

• click(WebElement element) – Clicks an element
• doubleClick(WebElement element) - Double-clicks an element.
• void mouseDown(WebElement element) - Holds down the left mouse button on an element.
• mouseUp(WebElement element) - Releases the mouse button on an element.
• mouseMove(WebElement element) - Moves element form current location to another element.
• contextClick(WebElement element) - Performs a context-click (right click) on an element.

Question 51:

How does Android Webdriver works?

Answer

Android WebDriver uses Remote WebDriver. Client Side is test code and Server side is application installed on android emulator or actual device. Here client and server communicate using JSON wire protocol consisting of Rest requests.

Question 52:

What are the advantages of using Android WebDriver?

Answer

Android web driver runs on Android browser which is best real user interaction. It also uses native touch events to emulated user interaction.

But there are some drawbacks also like, it is slower than headless WebKit driver. XPath is not natively supported in Android web view.

Question 53:

Is there a built-in DSL (domain specific language) support available in WebDriver?

Answer

There is not, but you can easily build your own DSL, for example instead of using –

webDriver.findElement(By.name("q")).sendKeys("Test");

You can create a more composite method and use it –

public static void findElementAndType(WebDriver webDriver, String elementLocator, String testData) {

webDriver.findElement(By.name(elementLocator)).sendKeys(testData);

}

And now you just need to call method findElementAndType to do type operation.

Question 54:

What is grid2?

Answer

Grid2 is Selenium grid for Selenium 1 as well as WebDriver, This allows to –

·         Execute tests on parallel on different machines

·         Managing multiple environments from one point

Question 55:

How do I start hub and slaves machines in grid 2?

Answer

Navigate to you selenium server standalone jar download and execute following command –

java -jar selenium-server-standalone-.jar -role hub

And you start Slave machine by executing following command –

Java –jar selenium-server-.jar –role webdriver  -hub http://localhost:4444/grid/register -port 6666

Question 56:

And how do I run tests on grid?

Answer

You need to use the RemoteWebDriver and the DesiredCapabilities object to define browser, version and platform for testing. Create Targeted browser capabilities as –

DesiredCapabilities capability = DesiredCapabilities.firefox();

Now pass capabilities to Remote WebDriver object –

WebDriver driver = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), capability);

Following this, hub will take care of assigning tests to a slave machine

Question 57:

What parameters can be passed to grid2?

Answer

You can pass following parameters to grid 2 –

• -port 4444 (default 4444)
• -nodeTimeout (default 30) the timeout in seconds before the hub automatically releases a node that hasn't received any requests for more than the specified number of seconds.
• -maxConcurrent 5 (5 is default) The maximum number of browsers that can run in parallel on the node.