How to import `NodeJS.Timer` type in react-native

Question

I want to use the type NodeJS.Timer as a type annotation in one of my classes:

const interval: NodeJS.Timer = setInterval(this._func, 1000)

How can I import this type? I am using flow.

Answer 1

Flow uses the IntervalID type as the return type from the setInterval/setTimeout functions. You can see the function typedef here in the core defs.

To use it, just type interval with that type:

const interval: IntervalID = setInterval(this._func, 1000)