Question

I have a simple task to display a fruit object based on certain conditions. For example, if I need to show a banana I need to make sure the other fruits don’t display.

For simplicity’s sake, let’s say they are 4 possible fruits. Do I need to test all the possible combinations?

Test1 if banana not strawberry
Test2 if banana not apple
Etc.

Answer 1

You need to test as many combinations as there are code paths, for sure. If there’s no strawberry-specific or apple-specific code, then you don’t need to test both banana v. strawberry and banana v. apple. But if there’s different code for a given fruit, you need to test it, as well as one of the others; and if there’s different code based on the number of fruits, then you need to test 0, 1, 2, N-1, N, and N+1, whatever the largest value of N is. In general, you need to test enough to convince yourself additional tests wouldn’t help.