JarCastingDeprecated
Is npm bugging you about this module being deprecated? You are probably depending on this module via the source-map-resolve package. For example:
nanomatch > snapdragon > source-map-resolve > urix
The solution is to make your dependency chain update to source-map-resolve version 0.6.0 or later, or switch to dependencies not using source-map-resolve at all.
If you are looking for a way to normalize between Windows and Unix paths, just do it in whatever way makes sense for your project. This module is just weird.
Overview 
Makes Windows-style paths more unix and URI friendly. Useful if you work with paths that eventually will be used in URLs.
var urix = require("urix")
// On Windows:
urix("c:\\users\\you\\foo")
// /users/you/foo
// On unix-like systems:
urix("c:\\users\\you\\foo")
// c:\users\you\foo
Installation
npm install urix
var urix = require("urix")
Usage
urix(path)
On Windows, replaces all backslashes with slashes and uses a slash instead of a drive letter and a colon for absolute paths.
On unix-like systems it is a no-op.