jenny is tool for generating regression tests. Any time exhaustive testing looks painful due to the combinatorial explosion of features interactions to be tested, consider using jenny. It will cover most of the interactions with far fewer testcases. It can guarantee pairwise testing of all features that can be used together, and it can avoid those feature combinations that cannot.
Learn more about combinatorial testing.
Let's imagine we have a program with three features and various values for each feature:
- Sex (2): ♀️, ♂️
- Weather (3): 🌧, ☀️, 🌥
- Mood (3): 🤒, 😧, 😴
Jenny can generate combinations:
$ ./jenny -n3 2 3 3
1a 2a 3a
1b 2b 3b
1b 2c 3c
1a 2b 3c
1b 2a 3c
1a 2c 3b
1b 2b 3a
1b 2a 3b
1a 2c 3a
1a 2a 3b
1a 2c 3c
1b 2a 3a
1a 2b 3b
1b 2c 3a
1a 2b 3a
1b 2b 3c
1a 2a 3c
1b 2c 3b
where 3 is a number of features in combination, 2, 3 and 3 are numbers of possible values for the appropriate feature. Total number of possible unique combinations is 18.
$ cat jenny.sed
# number the testcases
=
# Dimension 1
s/ 1a / ♀️ /g
s/ 1b / ♂️ /g
# Dimension 2
s/ 2a / 🌧 /g
s/ 2b / ☀️ /g
s/ 2c / 🌥 /g
# Dimension 3
s/ 3a / 🤒 /g
s/ 3b / 😧 /g
s/ 3c / 😴 /g
$ ./jenny -n3 2 3 3 | sed -f jenny.sed
1 ♀️ 🌧 🤒
2 ♂️ ☀️ 😧
3 ♂️ 🌥 😴
4 ♀️ ☀️ 😴
5 ♂️ 🌧 😴
6 ♀️ 🌥 😧
7 ♂️ ☀️ 🤒
8 ♂️ 🌧 😧
9 ♀️ 🌥 🤒
10 ♀️ 🌧 😧
11 ♀️ 🌥 😴
12 ♂️ 🌧 🤒
13 ♀️ ☀️ 😧
14 ♂️ 🌥 🤒
15 ♀️ ☀️ 🤒
16 ♂️ ☀️ 😴
17 ♀️ 🌧 😴
18 ♂️ 🌥 😧