ZCCADCDEDB567ABAE643E15DCF0974E503Z 和 TypeScript - 返回的 _id 格式奇怪

Question

Have some strange response when querying MongoDB (via Mongoose) from TypeScript.

Having these two intrfaces:

import { Document, Types } from "mongoose";

export interface IModule extends Document {
  _id: Types.ObjectId;
  name: string;
  owner: number;
  isMain: boolean;
  url: string;
}

export interface IProject extends Document {
  _id: Types.ObjectId;
  name: string;
  description: string;
  owner: number;
  modules: IModule[];
}

And these are Mongoose schemas and models:

import { IModule, IProject } from "../interfaces/mongo";

export const ModuleSchema = new mongoose.Schema({
  name: { type: String, required: true },
  owner: { type: String, required: false },
  isMain: { type: Boolean, required: true },
  url: { type: String, required: false },
});

export const ModuleModel = mongoose.model<IModule>("Module", ModuleSchema);

export const ProjectSchema = new mongoose.Schema({
  name: { type: String, required: true },
  description: { type: String, required: false },
  owner: { type: Number, required: true },
  modules: [ModuleSchema],
});

export const ProjectModel = mongoose.model<IProject>("Project", ProjectSchema);

Using model.find to return all documents where the owner is equal to 13

await ProjectModel.find({ owner: 13 })
  .select("-__v")
  .lean()
  .exec();

And this is what im getting in Postman as response. Not sure why _id is back in such format. I've tried to change the type of _id in the interface but it always comes back like this

    {
        "_id": {
            "_bsontype": "ObjectID",
            "id": {
                "type": "Buffer",
                "data": [
                    96,
                    173,
                    237,
                    68,
                    72,
                    243,
                    160,
                    124,
                    92,
                    93,
                    142,
                    242
                ]
            }
        },
        "name": "whatever-repo",
        "description": "",
        "owner": 13,
        "modules": [
            {
                "_id": {
                    "_bsontype": "ObjectID",
                    "id": {
                        "type": "Buffer",
                        "data": [
                            96,
                            174,
                            108,
                            154,
                            204,
                            174,
                            125,
                            138,
                            184,
                            56,
                            58,
                            227
                        ]
                    }
                },
                "owner": "13",
                "isMain": false,
                "name": "whatever-repo-module4",
                "url": "test/whatever-repo-module4"
            },
...

Answer 1

The interface in TypeScript is not checked in runtime - it is only checked in compile time. Thus, you can't simply change the runtime structure directly in interface .

For this case, you can use .map(val => val.id =...) if it returns an array, or .id =... if it returns simply an object. To ensure not modifying the original object, it is better to deep copy your object first.