Yeah the compiler guarantees that a certain class of errors can never happen and thus you don't need to go through significant effort to cover things like error

Yeah the compiler guarantees that a certain class of errors can never happen and thus you don't need to go through significant effort to cover things like error returns. Additionally with a dynamic language where the codebase has less than a 100% test coverage I would find it very hard to refactor anything without sweating bullets. The compiler is giving you a free test suite.