Keys

See source on Github 

A type helper that returns an array of keys for the properties of a given object type T. Useful in conjunction with Object.keys when one needs to preserve the types of the keys.

Example

const breakpoints = {
  xs: 500,
  md: 1000,
}
 
const keys = Object.keys(breakpoints) as Keys<typeof breakpoints>
 
for (const key of keys) {
  console.log(key) // Typed as: "xs" | "md"
}