TDD Interview Questions (2024)

1. What is TDD?

2. What are the different steps involved in TDD?

3. What are the advantages of TDD?

4. What are the disadvantages of TDD?

5. Do you use TDD in your work, and if so, why?

6. How is BDD different from TDD (Test-Driven Development)?

7. What is the difference between Acceptance TDD and Developer TDD?

8. What is Agile Model Driven Development (AMDD) in TDD?

9. What is the difference between TDD and AMDD?

10. What is accessibility Testing?

11. What is TDDD?

12. How do you write a test case for SQL queries?

13. Why is sanity check required in TDD?

14. When should regression testing be done and why in TDD?

15. What is CTDD?

16. What is the difference between unit testing and TDD?

17. What is CI with TDD?

18. What are different types of tests in Test Driven Development (TDD)?

19. What are different types of Automated Tests?

20. What Mockito in TDD?

21. What are the common testing tools used in DevOps for TDD?

Q: What is TDD?
Ans:

Test-driven development (TDD), also known as test-driven design, is a way of performing software programming that combines unit testing, programming, and refactoring on source code. Test-driven development was developed as part of the Extreme Programming (XP) software design paradigm, which is part of the Agile software development approach.

Q: What are the different steps involved in TDD?
Ans:

The main component of test-driven development is regular or quick cycles of testing, coding, and reworking, with testing coming first. These cycles move at such a rapid pace that manual operation is not an option.
Following are the steps in TDD:

1. Examine and create test cases.
2. Red - Create a failing unit test
3. Green - Complete the code and pass the new test case.
4. Green -Verify that all previous test cases have passed.
5. Clean up the code by refactoring it.
6. Continue this cycle.

Q: What are the advantages of TDD?
Ans:

1. Quality: With test-driven development, applications of better quality can be created faster than with traditional development techniques.
2. Detect issues earlier, and facilitate quicker solution.
3. High test coverage : Compared to traditional phased code > test > repair > retest cycles, TDD's methodical approach assures substantially higher coverage and first-time quality.
4. Less debugging: Testing is done early on in the design cycle, which reduces the lot of time and cost needed for debugging later on.

Q: What are the disadvantages of TDD?
Ans:

1. To be effective with TDD, especially at the unit level, need a skills.
2. Since many legacy systems were not designed with unit testing in mind, it is difficult to isolate components for testing.
3. When considering TDD, a business will need to put time and slow down initially in order to accelerate afterwards.

Q: Do you use TDD in your work, and if so, why?
Ans:

1. I create system behavior tests, not implementation tests, for my unit tests.
2. I make an effort to write my tests in a way that makes refactoring simple and doesn't break them.
3. Since it is hard to provide 100% test coverage in the event of specific issues, such as legacy systems that are incompatible.
4. I believe it is essential to verify that crucial system components produce the appropriate results for a variety of typical

Q: How is BDD different from TDD (Test-Driven Development)?
Ans:

Behaviour Driven Development (BDD) is intended to test an application's behaviour from the perspective of the end user, whereas TDD is intended to test smaller parts of functionality in isolation.

BDD is the next step in the evolution of TDD.
TDD requires developers to

1. write unit tests and observe them fail,
2. construct the feature to allow the tests to pass,
3. rewrite the code to make it stronger, and
4. continue the cycle. In BDD, teams do the same loop with feature tests (also known as "acceptance" or "black-box" tests) and unit tests.

Moreover, BDD incorporates shift left approaches such as Example Mapping and Specification by Example to ensure that teams understand what they are doing and concentrate on producing the right things.

Q: What is the difference between Acceptance TDD and Developer TDD?
Ans:

There are two TDD levels.

1. Acceptance TDD (ATDD)

   With ATDD, only one acceptance test needs to be written. This test validates the system's behavior or satisfies the specification's requirement. Create just enough production/functionality code to pass the acceptance test after that. The system's general behavior is the main focus of the acceptance test. A second name for ATDD was Behavioral Driven Development (BDD).

2. Developer TDD

   With Developer TDD, user create only required for production code to satisfy a single developer test, or unit test. The system's smallest features are the focus of the unit test. Developer TDD is referred to simply as TDD. The basic objective of ATDD and TDD is to just-in-time (JIT) describe specific, executable criteria for your solution.

Q: What is Agile Model Driven Development (AMDD) in TDD?
Ans:

AMDD, as its name suggests, is a agile manner of model driven development (MDD). In the MDD technique of software development, detailed models are made before any source code is produced. The Model Driven Architecture (MDA) standard of the Object Management Group (OMG) is a perfect example of MDD.

Q: What is the difference between TDD and AMDD?
Ans:

TDD is a method of software development that involves creating test cases before the software is completed and updating as needed in response to test findings. Model Driven Development (MDD), also known as MDA (Model Driven Architecture), is an agile variation of MDA in which detailed models are developed before source code is written.

Q: What is accessibility Testing?
Ans:

Making your web and mobile applications useful for as many users as possible involves the process of accessibility testing. It makes apps useful for people with impairments, such as those who suffer from hearing loss, vision impairment, or other physical or mental issues.

Q: What is TDDD?
Ans:

Test-driven database development, or TDDD, is a technique that utilizes unit tests to direct the database development process. As opposed to database development being first and SQL unit testing coming after, it is essentially SQL unit testing after database development.

Q: How do you write a test case for SQL queries?
Ans:

The following describes a common SQL unit testing scenario:

1. Create a database entity to satisfy a certain business need.
2. To validate the database object, create a SQL unit test.
3. Run a SQL unit test to see whether the database connection is up and running.
4. Continue to the following SQL unit test if the test is successful.

Q: Why is sanity check required in TDD?
Ans:

Sanity testing is done to make sure that the code changes are functioning as intended. Sanity testing is a pause that determines whether or not testing for the build may continue. During the sanity testing phase, the team's main goal is to verify the application's functionality rather than do in-depth testing.

Q: When should regression testing be done and why in TDD?
Ans:

After functional testing is complete, regression testing is carried out to ensure that the other functionalities are working. Regression testing is typically carried out by a software quality assurance team after the development team has finished their job.

As part of test-driven development (TDD), a test suite is run repeatedly, giving developers the confidence to make code modifications. However, running an entire test suite for each little code change is not always cost-effective. Because of this, regression test selection (RTS) methodologies are critical for TDD. TDD makes it especially challenging to select a small group of tests that are most likely to detect a regression flaw in a specific code update.

Q: What is CTDD?
Ans:

Continuous test-driven development (CTDD) is a software development approach that extends test-driven development (TDD) by doing automated tests in the background, also known as continuous testing.

Q: What is the difference between unit testing and TDD?
Ans:

Once we have completed our code development, then writing automated tests of code, it, is known as unit testing. In test-driven development (TDD), you write your unit tests before users write the production code and then run those tests repeatedly as users add new code.

While TDD also emphasizes design and testability, unit testing focuses on the functioning of the individual units. Writing unit test methods is part of TDD, though.

Q: What is CI with TDD?
Ans:

Continuous integration (CI) means build the application code when anything changes. Users have the option of running the test suite at that moment.

Q: What are different types of tests in Test Driven Development (TDD)?
Ans:

In Test Driven Development (TDD), there are five types of tests:

1. Unit tests

   A small section of code (typically a class or a method) is tested using replacements such as fake objects or method stubs.

2. Integration tests

   Individual software components are merged and tested as a group.

3. Functional tests

   Functional tests are a type of quality assurance test that assesses the entire functioning of the code and compares the actual results to the expected outcomes.

4. Regression testing

   Regression testing confirms that the new changes to the code have not resulted in any errors.

5. End-To-End Testing

   This is a comprehensive test that covers unit tests, functional tests, and integration tests, among other things.

Q: What are different types of Automated Tests?
Ans:

Automated tests are typically separated into below categories.

1. Unit tests

   Unit tests are run by developers first, and in some circumstances before they commit their modifications to the repository. Unit tests are typically used to test particular classes or functions. When those classes or functions require access to external resources, those resources are frequently impersonated as "mocks" or "stubs."

2. Integration tests

   Integration tests are the next step of testing after unit tests. Integration tests ensure that the elements that make up an application communicate correctly with one another. Integration tests should ideally be performed in situations similar to the production environment.

3. System tests

   The complete system should be tested in an environment as near to the real production environment as possible.

Q: What Mockito in TDD?
Ans:

Mockito enables programmers to build and test identical objects (mock objects) in automated unit tests for TDD . Mockito, in a nutshell, is a framework that developers use to efficiently write certain types of tests.

Q: What are the common testing tools used in DevOps for TDD?
Ans:

The following are some common testing tools used in DevOps:

1. Selenium
2. JUnit
3. TestNG
4. Cucumber
5. Qunit
6. Appium