Final answer:
Test-first development is a software development practice where tests, often unit tests, are written prior to the actual code to ensure that the code fulfills specified functional requirements. It is a foundational aspect of Test-Driven Development and helps to improve code quality by reinforcing a cycle of writing and testing.
Step-by-step explanation:
Test-first development is a software development approach where tests are written before the actual code. The concept emphasizes that developers first specify how the application should behave through tests, often unit tests, and only then write the code that fulfills these tests. This method is part of larger development methodologies such as Test-Driven Development (TDD) and is known for reinforcing the cycle of writing just enough code to pass the designed tests, thereby ensuring the software being developed is tested thoroughly. By focusing on the tests first, developers are encouraged to consider the requirements and design before writing the application code, which helps to clarify intentions, detect errors early, and improve code quality.
In the context of developing a writing project through multiple drafts, test-first development can be seen metaphorically. Just like a writer creates multiple drafts to shape the best paper possible, utilizing peer review and critical thinking, a developer using test-first approaches refines their code iteratively, responding to the feedback from the tests. Functional requirements of the software serve a similar role to a writer's guidelines, directing the development process to meet the established goals effectively.