The parameter err is not used and could be removed.
This check looks for parameters in functions that are not used in the function
body and are not followed by other parameters which are used inside the function.
If you intend to check if the variable error is declared in the current environment, consider using typeof error === "undefined" instead. This is safe if the variable is not actually declared.
This check looks for parameters in functions that are not used in the function body and are not followed by other parameters which are used inside the function.