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Potential Difficulties with Test-First Development

publish date: 2026/06/04 22:55:38.417471 UTC

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Although test-first development is a powerful innovation, it faces potential difficulties in practice. Which of the following are recognised difficulties? Select all that apply.

Automated test frameworks are too expensive for most organisations to afford

It is difficult to judge the completeness of a test set — crucial parts of the system may not be executed by the tests and so remain untested despite a large number of tests existing

Programmers sometimes take shortcuts when writing tests — for example writing incomplete tests that do not check all possible exceptions — because they prefer programming to testing

Test-first development always slows delivery so dramatically that it is impractical for commercial projects

Some functionality is difficult to test incrementally — for example, in a complex user interface it is often difficult to write unit tests for the display logic and workflow between screens

Correct Answer

(1) Programmers sometimes take shortcuts when writing tests — for example writing incomplete tests that do not check all possible exceptions — because they prefer programming to testing

(2) Some functionality is difficult to test incrementally — for example, in a complex user interface it is often difficult to write unit tests for the display logic and workflow between screens

(3) It is difficult to judge the completeness of a test set — crucial parts of the system may not be executed by the tests and so remain untested despite a large number of tests existing

Explanation

Three recognised difficulties with test-first development: (1) programmer shortcuts — programmers prefer programming to testing and may write incomplete tests that miss exceptions; (2) some tests are hard to write incrementally — particularly for complex UI display logic and screen workflows; (3) completeness is hard to judge — a large test set may still leave crucial parts of the system unexecuted and untested. Delivery speed and tool cost are not stated as difficulties.

Reference

Software Engineering, Ian Sommerville, 9th edition

Quizzes you can take where this question appears

Exercises: Applied Agile Development