rc-js-util/src/array/impl/array-normalize-empty-to-undefined.ts

A collection of TS and C++ utilities to help writing performant and correct applications, achieved through strict typing and (removable) invariant checking.

/**
 * @public
 * Replaces length 0 `ArrayLike` with `undefined`.
 * @returns `array` if it's an `ArrayLike` of length greater than 0, otherwise `undefined`.
 *
 * @remarks
 * See {@link arrayNormalizeEmptyToUndefined}.
 */
export function arrayNormalizeEmptyToUndefined<TArray extends ArrayLike<unknown>>
(
    array: TArray | null | undefined
)
    : TArray | undefined
{
    if (array == null || array.length === 0)
    {
        return undefined;
    }

    return array;
}