/**
 * 将 DTO 类型函数转换为可选版本
 * 返回 T | undefined，在 dto.Object()  dto.Array() 中会被识别为可选字段
 */
export function toOptional<T extends (...a: any) => any>(
    dtoFunc: T
): ReplaceReturnType<T, ReturnType<T> | undefined> {
    let optionalFunc = (...args: any[]) => {
        let dto = (dtoFunc as any)(...args)
        dto.isOptional = true
        return dto
    }
    return optionalFunc as any
}

/**
 * 将 DTO 类型函数转换为可空版本
 * 返回 T | null，在 dto.Object() dto.Array() 中会被识别为可选字段
 */
export function toNullable<T extends (...a: any) => any>(
    dtoFunc: T
): ReplaceReturnType<T, ReturnType<T> | null> {
    let optionalFunc = (...args: any[]) => {
        let dto = (dtoFunc as any)(...args)
        dto.isNullable = true
        return dto
    }
    return optionalFunc as any
}

type ReplaceReturnType<T extends (...a: any) => any, TNewReturn> = (...a: Parameters<T>) => TNewReturn