Selenium WebDriver Interview Questions

WebDriver in Selenium is a web automation framework. It allows the developers to execute their tests against different browsers. With this, the developers can also use different programming languages like Java, .net, PHP, Python, Perl, and Ruby in creating the test scripts. Conditional operations like if-else, switch-case, and loop operations like do-while are possible with the WebDriver. The Selenium WebDriver is considered as one of the most important components in the Selenium Tool’s suite.

There are four basic components present in the WebDriver architecture.

1. Bindings
2. JSON Wire Protocol
3. Browser Drivers
4. Real Browsers

Bindings are used by the developers in order to support multiple languages.

JSON Wire Protocol is a transport mechanism to transfer the data between a server and a client.

Browser Driver is specific to each browser to establish a secure connection with the browser without revealing the internal logic of the browser’s functionality.

Real browsers are the browsers supported by the Selenium. They are Mozilla Firefox, Safari, Internet Explorer, and Google Chrome.

Some of the limitations of the Selenium WebDriver are,

• Only support for Web-Based applications
• Takes time to create test cases
• Difficult to set up a test environment
• No support for automation of windows application
• No built-in reporting facility
• Doesn’t have test tool integration for test management
• Difficult to process popups or frames
• Doesn’t have the ability to automate captcha and OTP

The SearchContext is a topmost interface present in the Selenium WebDriver hierarchy. It has two methods that will be the abstract as SearchContext is an interface.

The two methods are the findElement() and findElements().

The findElement() is used to find the first WebElement that matches the current context.

The findElements() method is used to find all elements within the current context. It returns all the elements that match or returns empty if nothing matches.

There are different WebElements present in the Selenium to get the input from the user. They are TextBoxes, Password fields, Checkboxes, Radio buttons, file inputs, Dropdowns, etc. Developers can use any of these WebElements depending upon their needs to get the input from the user.

List some of the WbDriver Selenium commands are,

• get() - It takes a URL as its parameter and launches a new browser as it opens the specified URL in the browser instance.
• getClass() - It is used to retrieve the Class object that represents the runtime class of this object.
• getCurrentUrl() - It is used to retrieve the URL of the webpage that is currently processed by the user.
• getPageSource() - It is used to retrieve the page source of the webpage that is currently accessed by the user.
• getTitle() - It is used to retrieve the title of the webpage that is currently used by the user.
• getText() - It is used to retrieve the inner text of the specified web element.
• getAttribute() - It is used to retrieve the value of the specified attribute.
• getWindowHandle() - It is used to tackle the situation when there is more than one window to deal with.

To install Selenium WebDriver for python,

You need to have python installed on your device. Then, you can use the pip command to install the Selenium as follows.

pip install -U selenium

To check the version of the selenium webdriver installed, you can use the following command in the python shell.

selenium._version_

The WebDriver API gives a more simplistic and compact programming interface for the selenium.

They can be categorized into five types.

1. Domain
2. Synchronization
3. Navigation
4. Interrogation
5. Manipulation.

Some of the mainly used CSS selectors are,

• Tag and ID
• Tag and Class
• Tag and Attribute
• Tag, Class, and Attribute
• Child elements such as Direct child, Sub-child, nth-child
• And, Sub-Strings that matches start with (^), ends with ($) and contains (*)

There are three different types of waits available in Selenium.

They are the Implicit wait, Explicit wait, and Fluent wait.

The implicit wait will wait for all the findElement() and findElements() once it has been defined. The explicit wait is defined for a particular web element and will wait for that single web element. The fluent wait is similar to the explicit wait but we can ignore the exception and define the polling time in it.

The programming languages supported by the Selenium WebDriver are -

• Java
• Python
• Ruby
• C#
• JavaScript
• Perl
• PHP.

Some of the common Exceptions in the Selenium WebDriver are,

ElementNotVisibleException - Here, the element will not be visible even if it is present.

ElementNotSelectableException - Here, the element is disabled.

NoSuchElementException - Here, the WebDriver cannot determine the element during the runtime.

NoSuchFrameException - Here, the switching to an invalid frame by the WebDriver is unavailable.

NoAlertPresentException - Here, the switching to an invalid alert by the WebDriver is unavailable.

NoSuchWindowException - Here, the switching to an invalid window by the WebDriver is unavailable.

WebDriverException - Here, the WebDriver will be acting immediately after closing the browser.

TimeoutException - Here, the command will not be completed in the specified time.

SessionNotFoundException - It occurs when the session is not found in the Selenium WebDriver.

StaleElementReferenceException - Here, the referenced element is longer present on the DOM page.

MSBI stands for (Microsoft Business Intelligence). It is an ETL tool used for database operations. The MSBI in turn composed of different tools that help in providing the best solution for the Business Intelligence and the Data Mining Queries. The tools present in the MSBI are the SSIS, SSAS, and SSRS. The MSBI allows the user to gain access to accurate and up-to-date information for better decision making in the organization. It is a Business Intelligence (BI) solutions tool that uses Visual Studio with the SQL server.

The full form of the SSIS is SQL Server Integration Services.

Some of the advantages of using Selenium WebDriver are,

• Selenium WebDriver has support for all languages and framework
• It is an open-source tool. So it can be publicly accessible with no upfront cost
• The Selenium script is compatible with multiple browsers
• It also has support in the various OS such as Windows, Linux, Mac OS, Unix, etc
• The Selenium tests are reusable so it can be tested across different browsers and operating systems
• It offers great flexibility
• The Selenium automation framework is easy to use with a friendly interface

Some of the alternative tools to the Selenium WebDriver is,

UI.Vision Kantu - An open-source task and test automation tool.

Katalon Studio - A robust API, web, and mobile test automation solutions with continuous integration.

CasperJS - A Javascript-based open-source navigation scripting and testing utility.

Wildfire - A custom automation workflow tool.

TestCafe - A Node JS end-to-end solution for testing web applications.

Puppeteer - A Node JS library that offers a high-level API to control headless Chrome.

Cypress.io - A front end automated testing tool created for the modern web.

Robot framework - A generic test automation framework.

Some of the important components present in the SSIS are the packages, control flow elements, data flow elements, connection managers, variables, event handlers, and log providers.