Improving software delivery in every organisation

Well-designed tests

An Engineer with this core skill must be able to demonstrate good Test Design.

  • Avoid tight coupling between test code and production code
  • Conciseness of test suite
    • Maximizing behaviours tested by 1 suite
    • Minimizing audiences that a test suite speaks to


Something about conciseness.

Coupling between Test Cases and Production Code

Engineers that consider coupling avoid causing unnecessary code churn induced by too much tight coupling.

If there is one call-site to a particular function then that function is easy to change

It is desirable to ensure that the public interface of production code can evolve at a different rate to the test cases.

Conversely it is not desirable to need to update all your test cases to change the public interface

Reading Material

Marking scheme

  • Can identify smells within code they have written.
  • Can identify smells within somebody else’s code.
  • Can explain the balancing act of achieving conciseness of a test suite