如何使用 arrayUnion (TypeScript) 将字符串数组 append 转换为 Firebase 中的数组

Question

I am trying to use arrayUnion inside of a Firebase Cloud Function written in TypeScript. Whenever I add the array tho it adds the name of the variable "items" as well. Not sure why this is or what I'm doing wrong.

Picture of my database after appending 2 strings (This is obviously wrong):

My goal is to add a list of strings to my database. There should not be any duplicate ids in the unioned array.

What I've Tried

Firbase Function is called sucesfully with Array items = ['00000000000009', '00000000000008']

//Defined in class constructor
private firestore: FirebaseFirestore.Firestore


async addItemsToWishlist(uid: string, items: string[]): Promise<boolean> {
    try {
      // Nothing Added Function called for no reason
      if (items.length == 0) {
        return true;
      }

      console.log("Called Successfull with items: ", items);
      console.log("items length: ", items.length);

      // Add the items to the corresponding users Wishlist
      await this.firestore.collection("users").doc(uid).update({
        wishlistedItems: admin.firestore.FieldValue.arrayUnion(items),
      });

      // Return true if successful
      return true;
    } catch (e) {
      // Log the Error on the Console
      console.error(e);
      return false;
    }
}

Also not sure why i cant get the length of my array if items. Console logs:

Answer 1

From the log output it looks like your items is an object that contains an items child array, so you need to unwrap that before passing it to Firestore:

await this.firestore.collection("users").doc(uid).update({   // 👇
  wishlistedItems: admin.firestore.FieldValue.arrayUnion(items.items),
});