[Do you want a spanish version of this page? Follow this link].
Suppose you are the head of a publishing house, and that you need to hire a style and spelling checker. If you have a set of candidates, a possible way for selecting the best one is to give them a text (such as that on the left side, which is the first paragraph of
The Catcher in the Ray novel, by J.D. Salinger) with some errors, and then hiring that one who find more typos.
If you realy want to hear about it, the first thing you'll probably want know is where I was born, an what my lousy child hood was like, and how my parents where occupied and all be fore they had me, and all that David Coperfield kind of crap, but I don't feel like going in it, if you want to know the true.
If we're not in a mistake, there are the following nine typos in it:
If you really want to hear about it, the first thing you'll probably want to know is where I was born, and what my lousy childhood was like, and how my parents were occupied and all before they had me, and all that David Copperfield kind of crap, but I don't feel like going into it, if you want to know the truth.
When mutation was proposed more than 30 years ago, the basic idea behind it was the same: to evaluate the quality of test suites as a function of the number of faults detected by the cases in the test suite, when are executed against the SUT. As more faults are detected, higher is the test suite quality.
As well as we have "injected" artificial typos in the original Salinger's text, mutation relies on the insertion of artificial faults in the code of the system under test (the SUT). These artificial faults are inserted by means of "mutation operators", which introduce some kind of syntactic change in the SUT.
In next chapter we'll talk about mutation operators :)
