我的快递电话出了什么问题？我需要一个 ID 数组，但它返回一个空数组

正如@jabaa在他们的评论中指出的那样Promise，您的getIdsToDecline函数中存在错误链接的问题。

目前，该函数初始化一个名为 的数组tempArray，开始执行交易报价查询，然后返回该数组（当前仍为空），因为该查询尚未完成。

虽然你可以扔在await之前tradeOfferQuery.get()，这不会解决你的问题，因为它只会等待tradeOfferQuery执行和一批充满项，同时还不会等待任何的offerRef.get()呼叫完成填补tempArray。

为了解决这个问题，我们需要确保所有的offerRef.get()调用都先完成。要获取所有这些文档，您将使用以下代码获取每个文档，等待所有文档完成，然后提取快照：

const itemsToFetch = [ /* ... */ ];
const getAllItemsPromise = Promise.all(
  itemsToFetch.map(item => item.get())
);

const fetchedItemSnapshots = await getAllItemsPromise;

对于基于查询的文档，您可以将其调整为：

const querySnapshot = /* ... */;

const getSenderDocPromises = [];
querySnapshot.forEach((doc) => {
  const senderID = doc.get("senderID");
  const senderRef = db.collection("users").doc(senderID);

  getSenderDocPromises.push(senderRef.get());
}

const getAllSenderDocPromise = Promise.all(getSenderDocPromises);

const fetchedSenderDataSnapshots = await getAllSenderDocPromise;

然而，这两种方法都不是必需的，因为您使用这些offerRef.get()调用请求的文档已经在您的查询中返回，所以我们甚至不需要在get()这里使用！

(doc) => {
  let offerRef = db.collection("tradeOffers").doc(doc.id);
  //Change the status to declined
  batch.update(offerRef, { status: "declined" });
  //Get the data from the trade offer because I want to send an email 
  //to the  who just got their trade offer declined.
  const offerGet = offerRef.get().then((offer) => {
    const offerData = offer.data();
    //Check the items that the receiving person had in this trade offer
    const receiverItemIds = Array.from(
      offerData.receiversItems
        .reduce((set, { itemID }) => set.add(itemID), new Set())
        .values()
    );
    //if the receiver item id's array includes this item that just sold, I know that
    //I can get the sender ID (users can be sender or receiver, so i need to check which person is which)
    if (receiverItemIds.includes(listingID)) {
      tempArray.push(offerData.senderID);
    }
  });
}

可以替换为

(doc) => {
  // Change the status to declined
  batch.update(doc.ref, { status: "declined" });

  // Fetch the IDs of items that the receiving person had in this trade offer
  const receiverItemIds = Array.from(
    doc.get("receiversItems") // <-- this is the efficient form of doc.data().receiversItems
      .reduce((set, { itemID }) => set.add(itemID), new Set())
      .values()
  );

  // If the received item IDs includes the listed item, add the
  // sender's ID to the array
  if (receiverItemIds.includes(listingID)) {
    tempArray.push(doc.get("senderID"));
  }
}

可以简化为

(doc) => {
  //Change the status to declined
  batch.update(doc.ref, { status: "declined" });

  // Check if any items that the receiving person had in this trade offer
  // include the listing ID.
  const receiversItemsHasListingID = doc.get("receiversItems")
    .some(item => item.itemID === listingID);

  // If the listing ID was found, add the sender's ID to the array
  if (receiversItemsHasListingID) {
    tempArray.push(doc.get("senderID"));
  }
}

基于此，getIdsToDecline实际上排队拒绝无效交易并返回受影响的发件人的 ID。与其使用函数外部的batch和tradeOfferQuery对象使这变得更加不清楚，您应该将它们滚动到函数中并将其从 express 处理程序中拉出。我也会将其重命名为declineInvalidTradesAndReturnAffectedSenders.

async function declineInvalidTradesAndReturnAffectedSenders(listingID) {
  const tradeOfferQuery = db
    .collection("tradeOffers")
    .where("status", "==", "pending")
    .where("itemIds", "array-contains", listingID);

  const batch = db.batch();
  const affectedSenderIDs = [];
  
  const querySnapshot = await tradeOfferQuery.get();

  querySnapshot.forEach((offerDoc) => {
    batch.update(offerDoc.ref, { status: "declined" });

    const receiversItemsHasListingID = offerDoc.get("receiversItems")
      .some(item => item.itemID === listingID);

    if (receiversItemsHasListingID) {
      affectedSenderIDs.push(offerDoc.get("senderID"));
    }
  }

  await batch.commit(); // generally, the return value of this isn't useful

  return affectedSenderIDs;
}

然后这会将您的路由处理程序更改为：

app.post("/declineTrades", async (request, response) => {
  
  const listingID = request.body.listingID;
  
  const peopleToDeclineArray = await declineInvalidTradesAndReturnAffectedSenders(listingID);

  response.status(201).send({
    success: true,
    result: result,
    idArray: peopleToDeclineArray,
  });
});

然后添加适当的错误处理，换出HTTP 201 Createdfor的错误使用HTTP 200 OK，并使用json()代替send(); 你现在得到：

app.post("/declineTrades", async (request, response) => {
  try {
    const listingID = request.body.listingID;
  
    const affectedSenderIDs = await declineInvalidTradesAndReturnAffectedSenders(listingID);

    response.status(200).json({
      success: true,
      idArray: affectedSenderIDs, // consider renaming to affectedSenderIDs
    });
  } catch (error) {
    console.error(`Failed to decline invalid trades for listing ${listingID}`, error);

    if (!response.headersSent) {
      response.status(500).json({
        success: false,
        errorCode: error.code || "unknown"
      });
    } else {
      response.end(); // forcefully end corrupt response
    }
  }
});

注意：即使进行了所有这些更改，您仍然缺少任何形式的身份验证。考虑将 HTTPS 事件函数替换为可调用函数，该函数为您处理但需要使用 Firebase 客户端 SDK。