vm.createContext()

vm.createContext([sandbox])

If given a sandbox object, will "contextify" that sandbox so that it can be used in calls to vm.runInContext() or script.runInContext(). Inside scripts run as such, sandbox will be the global object, retaining all its existing properties but also having the built-in objects and functions any standard global object has. Outside of scripts run by the vm module, sandbox will be unchanged.

If not given a sandbox object, returns a new, empty contextified sandbox object you can use.

This function is useful for creating a sandbox that can be used to run multiple scripts, e.g. if you were emulating a web browser it could be used to create a single sandbox representing a window's global object, then run all <script> tags together inside that sandbox.