On the other hand an expressive static type system (with emphasis on expressive, because Java's type system doesn't qualify) can save you from countless of accidental bugs happening - and a single bug that's caught by the compiler is a bug that won't reach production.
Plus, static typing approaches the problem from a different perspective than unit testing. Through testing we try to prove that a piece of code conforms to the business logic that is being solved and to guard ourselves against regressions. A static type system on the other hand actually proves that your code has certain characteristics - for example depending on the language we are talking about, it can prove that you won't get any null pointer exceptions, or it can prove that the interface of this component is still the one expected by this other component, etc... for example I have a component modeled as a fairly complex FSM and I fixed a difficult non-deterministic bug by eliminating the possibility of it happening through the type-system - it was quite the eye opener.
Static typing doesn't negate the need for testing of course since they serve a different purpose, but if you find yourself writing tests for things that a compiler could prove, then you probably picked the wrong language.
On the other hand an expressive static type system (with emphasis on expressive, because Java's type system doesn't qualify) can save you from countless of accidental bugs happening - and a single bug that's caught by the compiler is a bug that won't reach production.
Plus, static typing approaches the problem from a different perspective than unit testing. Through testing we try to prove that a piece of code conforms to the business logic that is being solved and to guard ourselves against regressions. A static type system on the other hand actually proves that your code has certain characteristics - for example depending on the language we are talking about, it can prove that you won't get any null pointer exceptions, or it can prove that the interface of this component is still the one expected by this other component, etc... for example I have a component modeled as a fairly complex FSM and I fixed a difficult non-deterministic bug by eliminating the possibility of it happening through the type-system - it was quite the eye opener.
Static typing doesn't negate the need for testing of course since they serve a different purpose, but if you find yourself writing tests for things that a compiler could prove, then you probably picked the wrong language.