项目不想被推入数组

Question

我正在开发一个 discord 机器人，它允许您挖掘资源，但我无法让代码工作。 它正在记录实际项目，但它只是不将项目添加到数组中，这就是为什么我不能将它 map 转换为字符串。

代码：

module.exports.addItem = async (client, user, item, amount, interaction) => {
    if(!client instanceof Client) throw new Error("Client is not an instance of Discord.js Client");
    if(!user instanceof User) throw new Error("User is not an instance of Discord.js User");
    if(!item) throw new Error("Item is not defined");
    if(!amount) throw new Error("Amount is not defined");
    if(typeof amount !== "number") throw new Error("Amount is not a number");
    if(!interaction) throw new Error("Interaction is not defined");
    if(!interaction instanceof Interaction) throw new Error("Interaction is not an instance of Discord.js Interaction");

    const userFound = await client.database.user.findOne({ userID: user.id });
    if(!userFound) return interaction.followUp({ content: `You haven't started your journey yet!` });

    const itemFound = userFound.inventory.find(i => i.name === item.name);
        if(!itemFound) {
            await client.database.user.findOneAndUpdate(
                {
                    userID: user.id,
                }, {
                    userID: user.id,
                    $push: {
                        inventory: {
                            name: item.name,
                            amount,
                            category: item.category
                        }
                    }
                } , {
                    upsert: true,
            });
        } else {
            await client.database.user.findOneAndUpdate(
                {
                    userID: user.id,
                }, {
                    userID: user.id,
                    $pull: {
                        inventory: {
                            name: item.name
                        }
                    } 
                } , {
                    upsert: true,
            });
                
            await client.database.user.findOneAndUpdate(
                {
                    userID: user.id,
                }, {
                    userID: user.id,
                    $push: {
                       inventory: {
                            name: item.name,
                            amount: item.amount + amount,
                            category: item.category
                        }
                    }
                } , {
            upsert: true,
        });
    }
    return { name: item.name, amount, category: item.category };
}

module.exports.dropItem = async (client, user, category, interaction) => {
    if(!client instanceof Client) throw new Error("Client is not an instance of Discord.js Client");
    if(!user instanceof User) throw new Error("User is not an instance of Discord.js User");
    if(!category) throw new Error("Category is not defined");
    if(typeof category !== "string") throw new Error("Category is not a string");

    let droppedItems = [];
    
    for (const item of client.items) {
        for(let i = 0; i < client.items.length; i++) {
            if(!client.items[i].category === category) return;
        }

        const dropAmount = Math.floor((Math.random() * 3) + 1);
        const dropChance = Math.floor(Math.random() * 100);
        if(dropChance > item.dropChance) return;

        const itemDropped = await this.addItem(client, user, item, dropAmount, interaction)
        console.log(itemDropped); // This logs the item correctly

        droppedItems.push(itemDropped);
    }

    return droppedItems; // This always returns "undefined"
}

预期结果：一个包含对象的数组，每个 object 包含名称、数量和类别值；

实际结果：控制台记录数组返回“未定义”

我已经尝试等待推送，使数组成为常量和更多类似的小东西。 难道是因为数组不在循环中？

Answer 1

问题可能是您的 dropItem function 中有几个 return 语句返回undefined 。

例如if(dropChance > item.dropChance) return;

一个简单的 function 来说明这一点是：

const doSomething = () => {
    const arr = [1, 2, 3]
    for (const num of arr) {
        if (num !== 10) return
  }
    return 'done'
}

您是说您希望上面的 function 返回“完成”，但它实际上会返回undefined 。

我想也许您想使用break而不是return ，但不确定您期望的行为到底是什么。 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/break

Answer 2

由于您正在等待 for 循环中的调用，因此您还需要等待整个循环。 您可以使用await Promise.all(<<ARRAY OF PROMISES>>)执行此操作。

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all

所以你会做类似的事情

let droppedItems = [];
await Promise.all(client.items.map(async (item) => {
        for(let i = 0; i < client.items.length; i++) {
            if(!client.items[i].category === category) return;
        }

        const dropAmount = Math.floor((Math.random() * 3) + 1);
        const dropChance = Math.floor(Math.random() * 100);
        if(dropChance > item.dropChance) return;

        const itemDropped = await this.addItem(client, user, item, dropAmount, interaction)
        console.log(itemDropped); // This logs the item correctly

        droppedItems.push(itemDropped);
    }));