case design: Be aware of unwanted features

Omission detection is quite common when we design test cases, especially when using a “black box” testing, i.e, we focus on any “missing feature” as in AURS. However, this is not sufficient in some cases, we should also verify if the tested application has implemented “extra features” which may be harmful to customers/application.

Example is shown below:

A function f(x) will change the entry of record x, so the test criteria will be:

(1)              Is the record x changed properly?

(2)              All other records are not modified?