类型“Document<any>”不能赋值给类型“Pick<Pick<_LeanDocument<TicketDoc>”

Question

我有一个错误，在我的终端上就像泥巴一样清晰：

TSError：⨯无法编译TypeScript：

订单-depl-9fbcb84ff-ngt2z订单

src/models/ticket.ts(47,5)：错误TS2322:类型'Document‘不可分配给类型'Pick，“

_

id“|”

_

_

v“| "id”|“标题”|“价格”>| QuerySelector<...> |未定义‘。

订单-depl-9fbcb84ff-ngt2z订单

类型'Document‘缺少'Pick’类型的以下属性，“

_

id“|”

_

_

v“| "id”| " title“| " price ">'：标题，价格

它引用了这个模型文件：

import mongoose from 'mongoose';
import { Order, OrderStatus } from './order';

interface TicketAttrs {
  title: string;
  price: number;
}

export interface TicketDoc extends mongoose.Document {
  title: string;
  price: number;
  isReserved(): Promise;
}

interface TicketModel extends mongoose.Model {
  build(attrs: TicketAttrs): TicketDoc;
}

const ticketSchema = new mongoose.Schema({
  title: {
    type: String,
    required: true
  },
  price: {
    type: Number,
    required: true,
    min: 0
  }
}, {
  toJSON: {
    transform(doc, ret) {
      ret.id = ret._id;
      delete ret._id;
    }
  }
});

ticketSchema.statics.build = (attrs: TicketAttrs) => {
  return new Ticket(attrs);
};
// Run query to look at all orders. Find an order where the 
// ticket is the ticket just found *and* the order status is *not* cancelled.
// If we find an order from that means the ticket *is* reserved
ticketSchema.methods.isReserved = async function () {
  // this === the ticket document that I just called 'isReserved' on
  const existingOrder = await Order.findOne({
    ticket: this,
    status: {
      $in: [
        OrderStatus.Created,
        OrderStatus.AwaitingPayment,
        OrderStatus.Complete
      ]
    }
  });

  return !!existingOrder;
};

const Ticket = mongoose.model('Ticket', ticketSchema);

export { Ticket };

我不知道我在哪里犯了语法错误，我也不知道这种类型的

就是。看起来问题是

不是

但应等于

，除了它不是。

Answer 1

哇，这是TypeScript中的一个陷阱，你必须有深刻的知识才能弄清楚。下面是如何消除错误的方法：

// Run query to look at all orders. Find an order where the 
// ticket is the ticket just found *and* the order status is *not* cancelled.
// If we find an order from that means the ticket *is* reserved
ticketSchema.methods.isReserved = async function () {
  // this === the ticket document that I just called 'isReserved' on
  const existingOrder = await Order.findOne({
    //@ts-ignore
    ticket: this,
    status: {
      $in: [
        OrderStatus.Created,
        OrderStatus.AwaitingPayment,
        OrderStatus.Complete
      ]
    }
  });

  return !!existingOrder;
};

我通常不会这样做，因为它绕过了我们所依赖的TS检查，以确保一切都是类型安全的。不过现在，它起作用了，因为这个错误很奇怪，因为从技术上讲，这不是我在开发代码时做错了什么，我猜只是TypeScript的怪癖。