如何在 mongoose 中更新嵌套数组值？

问：

我对 nodejs/express 相当陌生，我正在用 devchallenges.io 练习全栈开发，我正在做 shoppingify 挑战。我正在尝试更新我在 items 数组中定位的项目的数量。我知道我下面的尝试很糟糕，我真的很难理解能够这样做的逻辑。

// @route    PUT api/list/item/quantity/:id
// @desc     Increase or decrease quantity
// @access   Private
router.put('/item/quantity/:id', auth, async (req, res) => {
  const { action } = req.body;
  try {
    let list = await List.findOne({ user: req.user.id });

    const item = list.items.find(
      (item) => item._id.toString() === req.params.id
    );
    list = list.updateOne(
      { 'items._id': req.params.id },
      { $set: { 'items.quantity': item.quantity + 1 } }
    );

    await list.save();
    return res.json(list);
  } catch (error) {
    console.error(error.message);
    res.status(500).send('Server Error');
  }
});

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const ListSchema = new Schema({
  user: {
    type: Schema.Types.ObjectId,
  },
  name: {
    type: String,
    default: 'Shopping List',
  },
  items: [
    {
      name: {
        type: String,
        default: '',
      },
      note: {
        type: String,
        default: '',
      },
      image: {
        type: String,
        default: '',
      },
      category: {
        type: String,
        default: '',
      },
      quantity: {
        type: Number,
        default: 1,
      },
    },
  ],
  date: {
    type: Date,
    default: Date.now,
  },
});

module.exports = List = mongoose.model('list', ListSchema);