The name
Kalku, the sorcerer
Where the name comes from, what each word of the cast is, and who the condor grinning beside it is.
kalku
In Mapuche belief, a kalku is a sorcerer who works in a hidden cave, the reni, and commands the wekufe, spirits that bring harm.
The tool borrows that cast because it does the same to your code: it casts one small defect into it at a time and sees whether any test notices.
The cast
Four words, and each one names a piece of the tool:
- kalku
- A worker bound to one language, which knows how to break code in that language.
- wekufe
- A mutant: your program with exactly one defect cast into it. The plural is the same word: wekufe.
- kalkutun / spell
- A kind of defect: drop a case clause, shift >= to >, swap and for or. Kalkutun is the harm a kalku works; code and protocol say spell.
- reni
- An isolated workspace where wekufe are cast. Your working tree is never touched.
Reports use plain words (killed, survived, timeout) so a CI log reads without the glossary.
Kalku
Kalku is a sorcerer condor: black, with a red headband and scarf and a grin full of teeth.
He is good, but he likes to look sinister. He breaks your code on purpose, and he does it for your sake: so you know whether your tests notice.
Madu, of the same family
Kalku is the brother of Madu, the pudú machi who is the mascot of Kimün, a tool that measures the health of your code from the terminal. Madu measures the code; Kalku breaks it to learn whether the tests notice.