Trouble with "OverwriteModelError: Cannot overwrite … model once compiled"

[theDanielJLewis]

Please help! I feel like I'm going crazy trying to figure this one out.

I'm getting the error "OverwriteModelError: Cannot overwrite 'Platform' model once compiled" on my project.

I'm using Typegoose 11.2.0, Mongoose 7.2.2, and Next.js 13.4.4.

Here's my Platforms model file:

import { getModelForClass, prop, modelOptions } from '@typegoose/typegoose';
import { Base } from '@typegoose/typegoose/lib/defaultClasses';

export interface PlatformClass extends Base {}
@modelOptions({
	options: { customName: 'Platform' },
})
export class PlatformClass {
	@prop()
	public name!: string;

	@prop()
	public slug?: string;

	@prop()
	public icon?: string;

	@prop({ type: () => [String] })
	public os?: string[];

	@prop()
	public accessToken?: string;

	@prop()
	public configurable?: boolean;
}

const Platform = getModelForClass(PlatformClass);

export default Platform;

I don't call this model in many places. But I keep getting the above error after some page refreshes.

contollers.platforms.ts:

import Platform, { PlatformClass } from '@/models/platforms';
import * as db from '@/utils/db';

export async function getPlatforms(query?: object): Promise<PlatformClass[]> {
	db.init();

	const platforms = await Platform.find(query);
	return platforms;
}

export async function getOnePlatform(query?: object): Promise<PlatformClass> {
	db.init();

	const platform = await Platform.findOne(query);
	return platform!;
}

services/platforms/app1.ts:

export async function getData(apId: number) {
	try {
		await db.init();
		const platform = await getOnePlatform({ name: 'Podchaser' });
		const { accessToken } = platform;
		// other stuff
	} catch (error) {
		console.error('Castbox get:', error);
		return;
	}
}

What am I doing wrong?

[theDanielJLewis]

Here's the full error stack:

error OverwriteModelError: Cannot overwrite `Platform` model once compiled.
    at eval (./src/models/platforms.ts:50:88)
    at (sc_server)/./src/models/platforms.ts (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5433:1)
    at __webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at eval (./src/controllers/platforms.ts:6:75)
    at (sc_server)/./src/controllers/platforms.ts (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5279:1)
    at __webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at eval (./src/services/platforms/app1.ts:9:80)
    at (sc_server)/./src/services/platforms/app1.ts (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5532:1)
    at __webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at eval (./src/services/platforms/index.ts:18:68)
    at (sc_server)/./src/services/platforms/index.ts (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5510:1)
    at __webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at eval (./src/controllers/podcasts/addPodcasts.ts:7:77)
    at (sc_server)/./src/controllers/podcasts/addPodcasts.ts (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5290:1)
    at __webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at eval (./src/controllers/podcasts/index.ts:10:70)
    at (sc_server)/./src/controllers/podcasts/index.ts (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5345:1)
    at __webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at eval (podcasts/[id]/layout.tsx:8:79)
    at (sc_server)/./src/app/(memberPages)/podcasts/[id]/layout.tsx (PROJECT_FOLDER/.next/server/app/(memberPages)/podcasts/[id]/reviews/page.js:5075:1)
    at Function.__webpack_require__ (PROJECT_FOLDER/.next/server/webpack-runtime.js:33:43)
    at async Promise.all (index 0)
    at async Promise.all (index 0)
    at async Promise.all (index 0)
digest: "3684533008"

[theDanielJLewis]

Maybe I found the solution from https://nesin.io/blog/fix-mongoose-cannot-overwrite-model-once-compiled-error?

I replaced my this statement:

const Platform = getModelForClass(PlatformClass);

export default Platform;

with this:

export const Platform =
	mongoose.models.Platform || getModelForClass(PlatformClass);

And I think it's working as expected now!

[RohitLakh]

From what I have seen and tried to solve, while using this is fine but this does not get the types that we want from using Typegoose over Mongoose.

If I use the Platform Model I won't be getting any type checks now.

[hasezoey]

@RohitLakh if your issue is that because of the const Model = Existing || New your types of Model are weird, you could force them to the proper type like const Model: ReturnModelType<typeof YourClass> = (and if any value conflicts, just cast it in this case)

[RohitLakh]

@hasezoey

This is what I am doing:

export const TriggerModel: ReturnModelType<typeof Trigger> = mongoose.models.Trigger || getModelForClass(Trigger);

This is what I am getting:

Type 'Model<any, {}, {}, {}, any, any>' is not assignable to type 'ReturnModelType<typeof Trigger>'.
  The types returned by 'findById(...)' are incompatible between these types.
    Type 'Query<(FlattenMaps<any> & Required<{ _id: unknown; }>)[] | (FlattenMaps<any> & Required<{ _id: unknown; }>) | null, any, {}, any, "findOne", {}>' is not assignable to type 'QueryWithHelpers<(FlattenMaps<Trigger> & { _id: ObjectId; }) | null, any, BeAnObject, Trigger, "findOne", IObjectWithTypegooseFunction>'.
      Type 'Query<(FlattenMaps<any> & Required<{ _id: unknown; }>)[] | (FlattenMaps<any> & Required<{ _id: unknown; }>) | null, any, {}, any, "findOne", {}>' is not assignable to type 'Query<(FlattenMaps<Trigger> & { _id: ObjectId; }) | null, any, BeAnObject, Trigger, "findOne", IObjectWithTypegooseFunction>'.
        The types returned by 'exec()' are incompatible between these types.
          Type 'Promise<(FlattenMaps<any> & Required<{ _id: unknown; }>)[] | (FlattenMaps<any> & Required<{ _id: unknown; }>) | null>' is not assignable to type 'Promise<(FlattenMaps<Trigger> & { _id: ObjectId; }) | null>'.
            Type '(FlattenMaps<any> & Required<{ _id: unknown; }>)[] | (FlattenMaps<any> & Required<{ _id: unknown; }>) | null' is not assignable to type '(FlattenMaps<Trigger> & { _id: ObjectId; }) | null'.

Am I doing something wrong here?

[hasezoey]

Am I doing something wrong here?

like i said, any incompatible value should be casted for this case: export const TriggerModel: ReturnModelType<typeof Trigger> = mongoose.models.Trigger as unknown || getModelForClass(Trigger); (this should work, if not try casting as any instead)

[RohitLakh]

@hasezoey

any worked. Been trying this for some time and didn't think of casting.

Appreciate the help!

[hasezoey]

from what i can tell, it looks like some kind of "hot-reloading" is the problem, it reloads the model file and wants to re-create the model, but does not reload the actual mongoose module (and so its already created models) and wants to add a model with the same name on the same connection / mongoose instance, which mongoose does not support

workarounds would be:

• just re-use the already existing model, like in Trouble with "OverwriteModelError: Cannot overwrite … model once compiled" #847 (comment), just note that changes to the model file will not be available via hot-reloading
• manually delete the model if it already exists before
• use something like nestjs-typegoose (links to a actually maintained version) - i dont know if it works correctly with hot-reloading (at least it wont complain)
• disable hot-reloading (or somehow add mongoose to it)