No Unused Locals Raise an error whenever a variable is declared but not used.

No Unused Parameters Raise an error whenever a function parameter is declared but not used.

No Unreachable Code Raise an error whenever a code path can never be reached.

No Implicit Returns Raise an error whenever some code paths in a function return, but others do not.

No Fallthrough Cases in Switch Raise an error when a non-empty case statement has no break after it.