articles.002.type-enumeraion-hack.tsx

type ButtonType = 'primary' | 'secondary' | 'link';

// First we will define a Record indexed by ButtonType
//
// Record type is smart enough to spot if we miss a ButtonType
// in its definition, if we leave e.g. the 'link', we will get an error
const butonTypesMap: Record<ButtonType, true> = {
  primary: true,
  secondary: true,
  link: true
};

// Then we take all the keys of our map and cast them to ButtonType
const buttonTypes: ButtonType[] = Object.keys(buttonTypeMap) as ButtonType[];
  
// This hack will only work for string union types though.
// It will not save you any typing and maybe even more importantly
// will intoduce type casting and an extra const.