Constants vs Enums in TypeScript

Playground link

Using an object as a collection of constants:

const ERROR_TYPES = {
  NAME_VALIDATION: 'name_validation',
  LENGTH_VALIDATION: 'length_validation',
  UNKNOWN: 'unknown'
} as const

// this creates: 'name_validation' | 'length_validation' | 'unknown'
type ERROR_STRINGS = typeof ERROR_TYPES[keyof typeof ERROR_TYPES] 

interface ErrorHandlersArgs {
   errorTypes: ERROR_STRINGS
}

function errorHandler({ errorTypes }: ErrorHandlersArgs) {}

// call it
errorHandler({ errorTypes: ERROR_TYPES.NAME_VALIDATION })

or using enums

// compiles to an object at runtime
enum ERROR_TYPES {
  NAME_VALIDATION = 'name_validation',
  LENGTH_VALIDATION = 'length_validation',
  UNKNOWN = 'unknown'
}


interface ErrorHandlersArgs {
    // this creates: 'name_validation' | 'length_validation' | 'unknown'
   errorTypes: ERROR_TYPES
}

function errorHandler({ errorTypes }: ErrorHandlersArgs) {}

// call it
errorHandler({ errorTypes: ERROR_TYPES.NAME_VALIDATION })