TypeScript Type: String matching pattern

Question

I am querying a system API (Linux' DBus API) that expects 3 string s:

• service
• path
• name

So I could write the signature of the TypeScript methods that calls the interface like so:

getInterface(service: string, path: string, name: string): DBusInterface;

But I know, service , path and name each follow specific string patterns:

• service = /^org\.bluez/
• path = /(\/[a-zA-Z]*)+/
• name = /([a-zA-Z]+\.)+/

(Regex not 100% correct, but here for comprehensibility)

I am wondering if it is possible to type guard the 3 parameters to match these patterns, like

type ServiceName: /^org\.bluez/

Answer 1

Currently as of 11/2019 this is not possible, there is an open suggestion for this for a while now that you can keep track of here https://github.com/Microsoft/TypeScript/issues/6579

You can read the comments and maybe find something useful