Test-driven development (TDD) in Software Engineering - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary purpose of writing tests before code in TDD?

In Test-driven development (TDD), developers write tests before writing the actual code. What is the main reason for this practice?

A To reduce the total number of tests needed later

B To avoid writing documentation for the code

C To delay coding until all requirements are finalized

D To ensure the code meets requirements and to guide design decisions

💡 Hint

Think about how tests influence the coding process and design.

Writing tests first helps clarify requirements and guides the design of the code to meet those requirements effectively.

📋 Factual

intermediate

Which of the following best describes the TDD cycle?

Identify the correct sequence of steps in the Test-driven development cycle.

A Write test → Write code → Refactor

B Write test → Refactor → Write code

C Refactor → Write test → Write code

D Write code → Write test → Refactor

💡 Hint

Remember the mantra: Red, Green, Refactor.

The TDD cycle starts by writing a failing test, then writing code to pass the test, and finally refactoring the code.

🔍 Analysis

advanced

What is a common risk if tests are not refactored during TDD?

During TDD, after making tests pass, developers refactor code and tests. What risk arises if tests are not refactored properly?

A The application will run faster

B Code coverage will automatically increase

C Tests may become brittle and fail unnecessarily on minor changes

D Developers will write fewer tests overall

💡 Hint

Consider how test quality affects maintenance.

If tests are not refactored, they can become tightly coupled to implementation details, causing failures when code changes even if behavior is correct.

❓ Comparison

advanced

How does TDD differ from traditional testing approaches?

Compare Test-driven development (TDD) with traditional testing methods. Which statement best highlights a key difference?

A TDD requires no tests, while traditional testing requires many

B TDD integrates testing into the development process by writing tests first, while traditional testing often happens after coding

C Traditional testing focuses on writing tests before code, TDD writes tests after code

D TDD eliminates the need for debugging, traditional testing does not

💡 Hint

Think about when tests are created in each approach.

TDD emphasizes writing tests before code to guide development, whereas traditional testing usually occurs after the code is written.

❓ Reasoning

expert

Why might TDD improve software design quality?

Explain why practicing Test-driven development can lead to better software design.

A Because writing tests first forces developers to think about requirements and design in small, manageable units

B Because TDD removes the need for code reviews

C Because TDD guarantees zero bugs in the final product

D Because TDD allows skipping documentation

💡 Hint

Consider how TDD influences the way developers approach coding tasks.

Writing tests first encourages developers to focus on clear, testable requirements and modular design, improving overall software quality.