Generate-and-validate approaches compile and test each candidate patch to collect all validated patches that produce expected outputs for all inputs in the test suite.<ref name="genprog2009" /><ref name="kali" /> Such a technique typically starts with a test suite of the program, i.e., a set of [[test casescase (software)|test case]]s, at least one of which exposes the bug.<ref name="genprog2009" /><ref name="prophet" /><ref name="rsrepair">{{Cite book |last1=Qi |first1=Yuhua |title=Proceedings of the 36th International Conference on Software Engineering |last2=Mao |first2=Xiaoguang |last3=Lei |first3=Yan |last4=Dai |first4=Ziying |last5=Wang |first5=Chengsong |date=2014 |publisher=ACM |isbn=978-1-4503-2756-5 |series=ICSE 2014 |___location=Austin, Texas |pages=254–265 |chapter=The Strength of Random Search on Automated Program Repair |doi=10.1145/2568225.2568254 |s2cid=14976851}}</ref><ref name="spr">{{Cite book |last1=Long |first1=Fan |title=Proceedings of the 2015 10th Joint Meeting on Foundations of Software Engineering |last2=Rinard |first2=Martin |date=2015 |publisher=ACM |isbn=978-1-4503-3675-8 |series=ESEC/FSE 2015 |___location=Bergamo, Italy |pages=166–178 |chapter=Staged Program Repair with Condition Synthesis |citeseerx=10.1.1.696.9059 |doi=10.1145/2786805.2786811 |s2cid=5987616}}</ref> An early generate-and-validate bug-fixing systems is GenProg.<ref name="genprog2009" /> The effectiveness of generate-and-validate techniques remains controversial, because they typically do not provide [[#Limitations of automatic bug-fixing|patch correctness guarantees]].<ref name="kali" /> Nevertheless, the reported results of recent state-of-the-art techniques are generally promising. For example, on systematically collected 69 real world bugs in eight large [[C (programming language)|C software programs]], the state-of-the-art bug-fixing system Prophet generates correct patches for 18 out of the 69 bugs.<ref name="prophet" />
