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Guide: Third Law of Test-Driven Development (TDD)

What is the Third Law of TDD?
The Third Law of TDD states: 'You cannot write any production code until you have first written a failing unit test.'

Why is It Important?
It ensures that each piece of production code is sufficiently tested before it is implemented, leading to fewer defects and stronger, more reliable software. This approach minimizes the risk of regression.

How Does It Work?
The developer writes a test that fails, then writes minimum production code to pass the test and refactors the code.

Exam Tips: Answering Questions on Third Law of TDD
1. Understand the fundamental principle: You can't write production code until a test fails.
2. Be able to explain why it's essential: It safeguards against poor code quality and unnecessary features.
3. Be prepared to provide examples of how it is done: Writing a failing test, then production code to pass it.
4. Know the potential outcomes and benefits: This includes fewer bugs, simpler code, and improved design integrity.

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Third Law of TDD practice test

According to the Third Law of TDD, you cannot write more production code than is sufficient to pass the currently failing test. The key principle here is writing the simplest code possible to make the test pass. This emphasizes the importance of simplicity in coding. It ensures that the codebase remains maintainable and helps prevent over-engineering of the solution. It also helps the developer to focus better on the task at hand.

Time: 5 minutes   Questions: 5

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  • 4442 Superior-grade PMI Agile Certified Practitioner practice questions.
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  • 100% Satisfaction Guaranteed: Full refund with no questions if unsatisfied.
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  • Risk-Free Decision: Start with a 7-day free trial - get premium features at no cost!