TypeScript better enums

ts-better-enums.ts

//
// Thanks to Matt Pocock's video "Enums considered harmful"
// https://www.youtube.com/watch?v=jjMbPt_H3RQ
//
// Please note that enums per se are great in any language,
// but TypeScript's enums are implemented in a convoluted and verbose way (as of version 4.9)
// since JavaScript (as of ES2022) does not natively support enums
//

// This can be moved elsewhere
type EnumLike<T> = T[keyof T];

// "as const" turns this into a readonly, "real" constant
const LOG_LEVEL = {
  DEBUG: 'DEBUG',
  WARNING: 'WARNING',
  ERROR: 'ERROR',
} as const;

// This is the associated type of the readonly constant
// In case you want to use it as a type
type LogLevel = EnumLike<typeof LOG_LEVEL>

// Example function using the LogLevel associated type
function logMe(level: LogLevel, message: string): void {
  // ...
}

// Example usage of the example function
logMe('DEBUG', 'It works with literals');
logMe(LOG_LEVEL.DEBUG, 'As well as enum-like access');