is-in-enum.ts

/**
 * A typeguard to check if a value is valid entry in an Enum.
 * If it passes, the value will be typed as the enum
 * @param value value to check
 * @param enumType Enum to check against
 * @returns boolean and assigns type to value
 * @example
 * ```ts
 * enum TestEnum {
 *   Value1 = 'Value1',
 *   Value2 = 'Value2',
 * }
 *
 * const result = isInEnum('Value1', TestEnum);
 * // result is true
 *
 * const value = 'Value1'; // value is of type string
 * if(isInEnum(value, TestEnum)) {
 *  doSomething(value); // value is of type TestEnum now. You're welcome.
 * }
 * ```
 */
export function isInEnum<T>(value: unknown, enumType: T): value is T[keyof T] {
    return Object.values(enumType).includes(value);
}