Property 'updateDescription' does not exist on type 'Document<unknown, any

[dong-lufei]

Prerequisites

• I have written a descriptive issue title

Mongoose version

6.8

Node.js version

18.13.0

MongoDB version

6.0.4

Operating system

Windows

Operating system version (i.e. 20.04, 11.3, 10)

10.0.22000

Issue

import { model, Schema } from "npm:mongoose@^6.8";

// Define schema.
const dinosaurSchema = new Schema({
  name: { type: String, unique: true },
  description: String,
  createdAt: { type: Date, default: Date.now },
  updatedAt: { type: Date, default: Date.now },
});

// Validations
dinosaurSchema.path("name").required(true, "Dinosaur name cannot be blank.");
dinosaurSchema.path("description").required(
  true,
  "Dinosaur description cannot be blank.",
);

// Methods.
dinosaurSchema.methods = {
  // Update description.
  updateDescription: async function (description: string) {
    this.description = description;
    return await this.save();
  },
};

// Export model.
export default model("Dinosaur", dinosaurSchema);

import mongoose from "npm:mongoose@^6.8";
import Dinosaur from "./model/Dinosaur.ts";

await mongoose.connect("mongodb://localhost:27017");

// Check to see connection status.
console.log(mongoose.connection.readyState);

// Create a new Dinosaur.
const deno = new Dinosaur({
  name: "Deno",
  description: "The fastest dinosaur ever lived.",
});

// // Insert deno.
await deno.save();

// Find Deno by name.
const denoFromMongoDb = await Dinosaur.findOne({ name: "Deno" });
console.log(
  `Finding Deno in MongoDB -- \n  ${denoFromMongoDb?.name}: ${denoFromMongoDb?.description}`,
);

// Update description for Deno and save it.
await denoFromMongoDb?.updateDescription(
  "The fastest and most secure dinosaur ever lived.",
);

The last method above updateDescription code hints that the type is wrong：

Property 'updateDescription' does not exist on type 'Document<unknown, any, { createdAt: Date; updatedAt: Date; description?: string | undefined; name?: string | undefined; }> & { createdAt: Date; updatedAt: Date; description?: string | undefined; name?: string | undefined; } & { ...; }'.deno-ts(2339)

[IslandRhythms]

Am able to reproduce

[r3wt]

nasty but works:

type T1=any;
type AccountMethods = { checkPassword: (candidatePassword: string)=>Promise<boolean>; };
const AccountSchema = new Schema<T1,Model<T1, any, AccountMethods, any>,AccountMethods>({});

[vkarpov15]

Does this issue just show up in VS Code highlighting, or is there an actual failure when you run tsc?

[IslandRhythms]

@vkarpov15 failure when running tsc

import * as mongoose from "mongoose";

// Define schema.
const dinosaurSchema = new mongoose.Schema({
  name: { type: String, unique: true },
  description: String,
  createdAt: { type: Date, default: Date.now },
  updatedAt: { type: Date, default: Date.now },
});

// Validations
dinosaurSchema.path("name").required(true, "Dinosaur name cannot be blank.");
dinosaurSchema.path("description").required(
  true,
  "Dinosaur description cannot be blank.",
);

// Methods.
dinosaurSchema.methods = {
  // Update description.
  updateDescription: async function (description: string) {
    this.description = description;
    return await this.save();
  },
};

const Dinosaur = mongoose.model('Dinosaur', dinosaurSchema);

async function run() {
  await mongoose.connect('mongodb://localhost:27017');
  await mongoose.connection.dropDatabase();

  // Check to see connection status.
console.log(mongoose.connection.readyState);

// Create a new Dinosaur.
const deno = new Dinosaur({
  name: "Deno",
  description: "The fastest dinosaur ever lived.",
});

// // Insert deno.
await deno.save();

// Find Deno by name.
const denoFromMongoDb = await Dinosaur.findOne({ name: "Deno" });
console.log(
  `Finding Deno in MongoDB -- \n  ${denoFromMongoDb?.name}: ${denoFromMongoDb?.description}`,
);

// Update description for Deno and save it.
await denoFromMongoDb?.updateDescription(
  "The fastest and most secure dinosaur ever lived.",
);
}

run();

[vkarpov15]

If you don't want to mess with generics, the preferred approach is to define your methods directly in your call to the Mongoose Schema() constructor using the methods option as follows. This allows Mongoose's automatic type inference to pick up your methods:

// Define schema.
const dinosaurSchema = new mongoose.Schema({
  name: { type: String, unique: true },
  description: String,
  createdAt: { type: Date, default: Date.now },
  updatedAt: { type: Date, default: Date.now },
}, {
  methods: {
    updateDescription: async function (description: string) {
      this.description = description;
      return await this.save();
    }
  }
});

If you can't use that approach, you can pass generics to your Schema constructor as follows:

interface DinosaurType {
  name?: string;
  description?: string;
  createdAt: Date;
  updatedAt: Date;
}

// Define schema.
const dinosaurSchema = new mongoose.Schema<DinosaurType, mongoose.Model<DinosaurType>, { updateDescription: Function }>({
  name: { type: String, unique: true },
  description: String,
  createdAt: { type: Date, default: Date.now },
  updatedAt: { type: Date, default: Date.now },
});

We'll add some notes to the Mongoose docs about this.