未处理的错误TypeError：无法读取Array.forEach（本机）在/user_code/lib/index.js:1352:24处未定义的属性“ forEach”

Question

你好，我正在创建一个可调用的Firebase云函数，该函数将返回一个数组。但是它什么也不会返回，所以我检查了功能控制台并显示了一个错误：

Unhandled error TypeError: Cannot read property 'forEach' of undefined
    at /user_code/lib/index.js:1352:24
    at Array.forEach (native)
    at Object.<anonymous> (/user_code/lib/index.js:1346:42)
    at next (native)
    at fulfilled (/user_code/lib/index.js:4:58)
    at process._tickDomainCallback (internal/process/next_tick.js:135:7)

我让您键入强制转换所有数组，但仍然显示错误。这是该功能的代码

export const getRelatedItems = functions.https.onCall(async (data, context)=>{
    const searchItemCategory:string = data.item_category;
    const relateItemUids:string[] = [];
    let uniqueWordArray:string[] = [];
    let wordCountArray:number[] = [];
    const relatedItemMap = [];
    const user_uid = data.current_user_uid;

    const userItemProfileQuery = await admin.firestore()
        .doc('User_Item_Profile/'+user_uid+'/user_item_profile/'+searchItemCategory)
        .get();

    if (userItemProfileQuery.exists){
        console.log('User has an existing User Item Profile');

        const userItemProfileDoc = userItemProfileQuery.data();
        uniqueWordArray = userItemProfileDoc['user_item_profile_attributes'];
        wordCountArray = userItemProfileDoc['user_item_profile_count'];

    }

    console.log("Looking for items that belong to the "+searchItemCategory+" category");
    //get items with the same item category
    const querySnapshot = await admin.firestore().collection('Item_Profile')
        .where("item_profile_item_category", "==", searchItemCategory).get();

    const resultDocs = querySnapshot.docs;
    console.log('There are '+resultDocs.length+' in the '+searchItemCategory);

    const readPromise = await resultDocs.forEach(async function (doc) {
        const itemProfile = doc.data();
        const itemUid = itemProfile['item_profile_item_uid'];
        const itemProfileAttributeWords:string[] = itemProfile['item_profile_attribute_words'];
        const itemProfileAttributeWeight:number[] = itemProfile['item_profile_attribute_weights'];
        let itemScore:number = 0;

        uniqueWordArray.forEach(function (attributeWord) {
            console.log(itemProfileAttributeWords);
            console.log(attributeWord);
            if (arrayContains(itemProfileAttributeWords, attributeWord)){
                const indexOfAttributeWord = itemProfileAttributeWords.indexOf(attributeWord);
                const indexOfUniqueWord = uniqueWordArray.indexOf(attributeWord);
                const weight = itemProfileAttributeWeight[indexOfAttributeWord];
                const wordCount = wordCountArray[indexOfUniqueWord];

                console.log("The word "+attributeWord+" is in the query and has a score of "+(weight*wordCount));

                itemScore+=(weight*wordCount);
            }
        });

        console.log("Stored the item "+itemUid+" with a score of "+itemScore+" to the Map");
        relatedItemMap.push([itemUid, itemScore]);
    });

    console.log("Started Sorting the Map");
    //sort the map based on the score for each item in ascending order
    const sortedArray = relatedItemMap.sort(function (a,b) {
        return a[1]<b[1]? 1:a[1]>b[1]?-1:0;
    });

    console.log("Finished Sorting the Map");

    sortedArray.forEach(function (item) {
        relateItemUids.push(item[0]);
    });

    relateItemUids.forEach(function (item) {
        console.log("Recommended Item UID: "+item);
    });

    console.log("Array of related item uids has been sent");
    return {
        itemUids: relateItemUids
    }
});

过去三天我一直在尝试解决此问题，但似乎无法解决