Ujanibishaji wa mabadiliko unatathmini ubora wa mkusanyiko wa majaribio kwa kuanzisha makosa machache yanayokusudiana ("mutants") kwenye nambari na kuangalia kama majaribio yanayayapiga. Inapima jinsi majaribio yanavyofanya kazi katika kubaini kasoro — inakwenda zaidi ya mfumo wa uendeshaji, ambao hupima uendeshaji tu.
Jinsi ujanibishaji wa mabadiliko unavyofanya kazi
1. A tool makes small changes (MUTATIONS) to the code, e.g.:
→ change + to -, > to >=, true to false, remove a statement, change a constant
→ each mutation = a deliberate "bug" (a MUTANT version of the code)
2. Run the TEST SUITE against each mutant:
→ tests FAIL → the mutant is "KILLED" (good — tests caught the bug) ✓
→ tests PASS → the mutant "SURVIVED" (bad — tests DIDN'T catch the bug) ✗
3. MUTATION SCORE = % of mutants killed → measures how good the tests are at catching bugs
