[hiker]

No suite of tests is complete enough to replace a proof. Unless the domain is finite and the tests exhaust all values in it.

[melling]

Out of curiosity, are there any studies that compare error rates among languages? How much is gained by going from say, Java to Haskell, or from Haskell to Coq?

[fiddlerwoaroof]

There's this, according to which Clojure does nearly as well as Haskell or Scala: https://jaxenter.com/programming-languages-defect-prone-repo...