Drupal Testing Tips: Boundary Value analysis

Boundary Value analysis is one of the techniques used in software testing which involves designing of test cases to contain values at the edges, or in other words, it includes values in the minimum and maximum conditions. For testing a Drupal site, these conditions are addressed in the test cases so that we can capture and resolve them earlier, since such extreme ends commonly cause software faults. Boundary value analysis is a black box testing technique.

For example consider a program in which the system accepts values between 1 and 100.

The values to be checked in this scenario are:

1. Lower value - 1
2. Lower value
3. Lower value + 1
4. Upper value - 1
5. Upper value
6. Upper value + 1

So in this case we will check 0, 1, 2, 99, 100, 101. Here Lower value - 1 and upper value + 1 fails.

Common limitations of BVA:

1. Logical variables and boolean values cause problems for Boundary Value Analysis.
2. Boundary Value Analysis assumes that the variables should be truly independent which is not possible always.
3. Since the test cases obtained are with very little insight and imagination, BVA test cases have been found to be limited.