Strong Typed Switch Functional

switch.ts

const executeIfFunction =
	<Wrapped extends Unwrapped | (() => Unwrapped), Unwrapped>(f: Wrapped): Unwrapped =>
    	typeof f === 'function' ? f() : f;
  
 const switchf =
     <ValueType>(cases: { [key: PropertyKey]: ValueType }) =>
     (defaultCase: ValueType) =>
     (key: PropertyKey) =>
         cases.hasOwnProperty(key) ? cases[key] : defaultCase;
		 
 export const switchCase =
     <KeyType extends PropertyKey, ValueType>(cases: { [key in KeyType]?: ValueType }) =>
     (defaultCase: ValueType) =>
     (key: KeyType) =>
         executeIfFunction<ValueType | (() => ValueType), ValueType>(switchf<ValueType>(cases)(defaultCase)(key));