“The tools of the interviewer are his questions,” notes the Harvard Business Review, and through expert use of questions, an experienced interviewer sizes up an applicant’s skills, talents, and job suitability.
In case of a job opening for a Selenium Automation Tester, recruiters know that everything from the interview to your everyday job will be circumscribed by the sense of urgency. Contemporary interviews work with limited time and yet the HR team must pick someone who can deliver on a deadline, or else, app releases are at stake.
This is especially so for intermediate and senior-level Selenium testers. For entry-level or junior posts, recruiters may ask basic Selenium interview questions. However, when interviewing someone with 4 or more years of experience, interviewers are not only exhaustive, but also detailed in their approach. As a candidate, you are tested based on the breath of your knowledge as well as your experience in troubleshooting certain finer issues.
To help you prepare for a mid-career Selenium Automation Tester job, here are 7 tricky and nuanced interview questions with appropriate answers.
1. How to handle an Authentication Pop-up using Selenium WebDriver?
As IT is rapidly changing, likewise, applications must be more secure. So, many companies have their own proxy settings for applications. If you open their server in a browser, it will ask you to enter the credentials. Even Selenium needs to handle the same auth pop-up before accessing the server.
Here are 3 ways how you can do that.
– Via the URL
Here, one is passing the username and password via the URL.
The syntax is: http://username:password@URL
For example,
Username: rohit
Password: P@ssword
URL: www.myurl.com
String URL = “http://” + rohit + ”:” + P@ssword + “@” + www.myurl.com;
driver.get(URL);
Alert alert = driver.switchTo().alert();
alert.accept();
– Using AutoIT
Sample AutoIT script,
WinWaitActivate(“Authentication Required”,””)
Send(“rohit{TAB}P@ssword{ENTER}”)
The AutoIT script would be passed within the Java code
– With Alerts
One can handle auth pop-ups with alerts with,
driver.switchTo().alert();
//WebDriver Java Code for entering Username and Password
driver.findElement(By.id(“userID”)).sendKeys(“userName”);
driver.findElement(By.id(“password”)).sendKeys(“myPassword”);
driver.switchTo().alert().accept();
driver.switchTo().defaultContent();
In case passing by URL does not work, one can also obtain credentials by Chrome extensions and driver.
Here are 3 ways how you can do that.
– Via the URL
Here, one is passing the username and password via the URL.
The syntax is: http://username:password@URL
For example,
Username: rohit
Password: P@ssword
URL: www.myurl.com
String URL = “http://” + rohit + ”:” + P@ssword + “@” + www.myurl.com;
driver.get(URL);
Alert alert = driver.switchTo().alert();
alert.accept();
– Using AutoIT
Sample AutoIT script,
WinWaitActivate(“Authentication Required”,””)
Send(“rohit{TAB}P@ssword{ENTER}”)
The AutoIT script would be passed within the Java code
– With Alerts
One can handle auth pop-ups with alerts with,
driver.switchTo().alert();
//WebDriver Java Code for entering Username and Password
driver.findElement(By.id(“userID”)).sendKeys(“userName”);
driver.findElement(By.id(“password”)).sendKeys(“myPassword”);
driver.switchTo().alert().accept();
driver.switchTo().defaultContent();
In case passing by URL does not work, one can also obtain credentials by Chrome extensions and driver.
2. The Selenium script runs in Chrome but not in IE. What can be done?
HTML DOM rendering and CSSOM construction differs from one browser to the next. So, there may be multiple reasons for a script not working on IE. One can attempt to troubleshoot the problem by:
1. Using the updated Selenium IE Driver
2. Verifying that the IE driver and working environment are compatible
3. Configuring the IE driver with the setProperty method and by importing dependencies
4. Setting the same value for the ‘Enable Protected Mode’ option for all zones from the Security tab
5. Turning off the internet security settings in IE when running the script
6.Using CSS Selectors to minimise exceptions
7. Setting a registry entry
8. Avoiding declaring the driver instance as static for running scripts on browsers parallelly
9. Using the latest Selenium jars
10. Enabling Javascript on the IE browser
11. Using JavaScriptExecutor instead of native click when clicking elements
1. Using the updated Selenium IE Driver
2. Verifying that the IE driver and working environment are compatible
3. Configuring the IE driver with the setProperty method and by importing dependencies
4. Setting the same value for the ‘Enable Protected Mode’ option for all zones from the Security tab
5. Turning off the internet security settings in IE when running the script
6.Using CSS Selectors to minimise exceptions
7. Setting a registry entry
8. Avoiding declaring the driver instance as static for running scripts on browsers parallelly
9. Using the latest Selenium jars
10. Enabling Javascript on the IE browser
11. Using JavaScriptExecutor instead of native click when clicking elements
3. What is the difference between ChromeOptions and DesiredCapabilities?
ChromeOptions is a class that can be used to manipulate capabilities specific to ChromeDriver. For instance, you can disable Chrome extensions with:
ChromeOptions options = new ChromeOptions()
options.addArgument(“disable-extensions”);
ChromeDriver driver = new ChromeDriver(options);
DesiredCapabilities can also be used to manipulate a ChromeDriver session. To change individual web driver properties, DesiredCapabilities class provides key-value pairs.
But, ChromeOptions supports limited clients whereas DesiredCapabilities supports a vast number of clients. ChromeOptions is supported by Java and other languages. DesiredCapabilities is available in Java, but its use is deprecated. When working with a client library, like Selenium Ruby Client, the ChromeOption class will not be available and DesiredCapabilities will have to be used.
DesiredCapabilities are commonly used with Selenium Grid, for parallel execution of test cases on different browsers. However, one can use both DesiredCapabilities and ChromeOptions using merge:
DesiredCapabilities capabilities = new DesiredCapabilities();
options = new ChromeOptions();
options.merge(capabilities);
driver = new ChromeDriver(options);
ChromeOptions options = new ChromeOptions()
options.addArgument(“disable-extensions”);
ChromeDriver driver = new ChromeDriver(options);
DesiredCapabilities can also be used to manipulate a ChromeDriver session. To change individual web driver properties, DesiredCapabilities class provides key-value pairs.
But, ChromeOptions supports limited clients whereas DesiredCapabilities supports a vast number of clients. ChromeOptions is supported by Java and other languages. DesiredCapabilities is available in Java, but its use is deprecated. When working with a client library, like Selenium Ruby Client, the ChromeOption class will not be available and DesiredCapabilities will have to be used.
DesiredCapabilities are commonly used with Selenium Grid, for parallel execution of test cases on different browsers. However, one can use both DesiredCapabilities and ChromeOptions using merge:
DesiredCapabilities capabilities = new DesiredCapabilities();
options = new ChromeOptions();
options.merge(capabilities);
driver = new ChromeDriver(options);
4. Is it possible to do responsive web design testing using Selenium?
Responsive web design testing is important, since many users use smartphones or tabs, and not just laptops, to access applications. Manually testing the application across all the platforms would entail a cumbersome and time-consuming task, which could potentially delay releases. To automate RWD testing one can use the Galen Framework. This add-on runs in Selenium Grid and with it one can run parallel tests as well as have the tests run in a cloud.
For visual validations, one can do RWD testing with Ocular library. Similarly, WAVE Evaluator can be used for check compliance with accessibility standards automatically.
For visual validations, one can do RWD testing with Ocular library. Similarly, WAVE Evaluator can be used for check compliance with accessibility standards automatically.
5. What is the need of database automation testing? Is it possible to perform database testing with Selenium?
Currently, the amount of data being generated and used is increasing by the day. Moreover, with advanced front ends, back ends need to be more robust and detailed. Databases play a major role in storing and sequencing data.
– Defect-free data processing
– ACID properties validation (ACID means Atomicity, Consistency, Isolation and Durability)
– Accurate storage and retrieval of values in and from the database
– Data integrity and proper data mapping
– Bugs that cannot be found in front-end testing are brought to light
Yes, it’s possible to do database testing with Selenium. First you need to make a connection between the server and the database. To do so you need a JDBC connection. JDBC is an SQL-based Java API that allows for connectivity between the Java programming language and various databases. With JDBC it is possible to connect with the database and execute queries. Once these two steps are done, one can process the results. Key components of JDBC are:
1. Driver manager
2. Driver
3. Connection
The syntax to connect with the database is:
DriverManager.getConnection(URL, “userid”, “password” )
Similarly, the code to load the JDBC driver is:
Class.forName(“com.mysql.jdbc.Driver”);
To send queries to the database one can use the Statement object. Similarly, to process the data one can use a getXXX() method.
– Defect-free data processing
– ACID properties validation (ACID means Atomicity, Consistency, Isolation and Durability)
– Accurate storage and retrieval of values in and from the database
– Data integrity and proper data mapping
– Bugs that cannot be found in front-end testing are brought to light
Yes, it’s possible to do database testing with Selenium. First you need to make a connection between the server and the database. To do so you need a JDBC connection. JDBC is an SQL-based Java API that allows for connectivity between the Java programming language and various databases. With JDBC it is possible to connect with the database and execute queries. Once these two steps are done, one can process the results. Key components of JDBC are:
1. Driver manager
2. Driver
3. Connection
The syntax to connect with the database is:
DriverManager.getConnection(URL, “userid”, “password” )
Similarly, the code to load the JDBC driver is:
Class.forName(“com.mysql.jdbc.Driver”);
To send queries to the database one can use the Statement object. Similarly, to process the data one can use a getXXX() method.
6. Why are assertions important in Selenium? What are different types of assertions?
Assertions are important for validation. They clearly state whether or not a test case is behaving as expected. As a regression suite or sanity suite, for instance, runs for a long duration, it is not always possible to sit in front of the system and look at the execution. Assertions help testers mark test cases as passed or failed.
There are 2 types of assertions:
1. Soft assert
This type of assertion will just verify the condition and give the result, but it won’t abort the test case execution when the test case fails.
2. Hard Assert
This type of assertion checks for the expected result, and if the condition fails to match, it will abort execution and throw the “java.lang.AssertionError” exception.
The different types of hard assertions in Selenium are:
assertEquals()
assertNotEquals()
assertNull()
assertNotNull()
assertTrue()
assertFalse()
There are 2 types of assertions:
1. Soft assert
This type of assertion will just verify the condition and give the result, but it won’t abort the test case execution when the test case fails.
2. Hard Assert
This type of assertion checks for the expected result, and if the condition fails to match, it will abort execution and throw the “java.lang.AssertionError” exception.
The different types of hard assertions in Selenium are:
assertEquals()
assertNotEquals()
assertNull()
assertNotNull()
assertTrue()
assertFalse()
7. What is a data-driven framework? How does dataProvider help in data driven testing?
Data driven framework is a test automation framework in which the data feed for the test cases can take the form of databases, tables, or spreadsheets, as in the case of xlsx, xls, and csv files. With a single automation script, one can run tests for all the test data available in the files as the data sets are now separate from the test cases.
The @dataProvider annotation in TestNG, a testing framework, helps testers automate test cases and thereby achieve data-driven testing.
The annotation is:
@DataProvider(name= “searchProvider”)
The return type of the @dataProvider annotation is a 2D array. So, if the array is 3*4 objects, there will be 3 test cases, each having 4 parameters.
The @dataProvider annotation in TestNG, a testing framework, helps testers automate test cases and thereby achieve data-driven testing.
The annotation is:
@DataProvider(name= “searchProvider”)
The return type of the @dataProvider annotation is a 2D array. So, if the array is 3*4 objects, there will be 3 test cases, each having 4 parameters.
These 7 tricky and nuanced Selenium interview questions are sure to leave you wanting to delve deeper into core concepts and explore further the practical issues that may arise when testing. As you whet your appetite for more, have our dynamic skill assessment and machine learning algorithms vet your profile and pave the way for an automation tester job at a Fortune 500 company.
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