How do you type object keys in TypeScript?

Return type is a Record (generic) object. Where they keys can be a string, and the value can be a string.

const getDeviceInfo = (): Record<string,string> => {
	return {
		browserName: globals.device?.browserName,
		deviceType: globals.device?.deviceType
	}
}

If you want to type a method or nested object you can do this:

  items: <Set<string>>new Set(),