`isEnum` typeguard

isEnum.ts

export const isEnum = <T extends string | number, TEnumValue extends string>(enumVariable: { [key in T]: TEnumValue }) => {
  const enumValues = Object.values(enumVariable);

  return (value: unknown): value is TEnumValue => (typeof value === 'string' || typeof value === 'number') && enumValues.includes(value);
};

// with number indexes not allowed
export const isEnum = <T extends string, TEnumValue extends string>(enumVariable: { [key in T]: TEnumValue }) => {
  const enumValues = Object.values(enumVariable);

  return (value: unknown): value is TEnumValue => typeof value === 'string'  && enumValues.includes(value);
};