Dynamic module promises in the exports array is broken

[micalevisk]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

Since the commit be6d90a#diff-10d05a74883d097e0c5b94c8564bd68b26cfcc9c57b32e3e0c0024c9e91c3e88 (nestjs v6), the following is supposed to work but it doesn't:

const whenDynamicModule: Promise<DynamicModule> = Promise.resolve({
  module: class MyModule {},
})

@Module({
  imports: [whenDynamicModule],
  exports: [whenDynamicModule],
})
export class AppModule {}

it crashes with the following error:

Error: Nest cannot export a provider/module that is not a part of the currently processed module (Bar). Please verify whether the exported [object Promise] is available in this particular context.

Possible Solutions:
- Is [object Promise] part of the relevant providers/imports within Bar?

we can easily see that this is either a missing feature or a regression.

Minimum reproduction code

https://gitlab.com/micalevisk/nestjs-issue-13733

Steps to reproduce

git clone https://gitlab.com/micalevisk/nestjs-issue-13733
cd nestjs-issue-13733
npm ci
npm start
## se the error

Expected behavior

I tested it with nestjs v6, v7 (with a different error), v8, v9, v10 so I'm pretty sure that this was never supported besides what the type definition says.

I found that after testing the ConditionalModule feature with dynamic modules returning promises. I never saw anyone reporting this error before so I'd say that this is not common pattern at all.

I tried to fix this but due to the async nature I didn't managed to fix it easily.

So instead of starting supporting it now in v10, I'd rather prefer to drop the Promise<DynamicModule> type from exports in NestJS v11. Or just drop it now in v10 because it doesn't seem to be used anyway.

If anyone starting asking for such fix in <=v10, we could suggest them to use
exports: [YourDynamicModule] instead and tell them that this is not a feature but a wrong type definition.

Package

• I don't know. Or some 3rd-party package
• @nestjs/common
• @nestjs/core
• @nestjs/microservices
• @nestjs/platform-express
• @nestjs/platform-fastify
• @nestjs/platform-socket.io
• @nestjs/platform-ws
• @nestjs/testing
• @nestjs/websockets
• Other (see below)

Other package

No response

NestJS version

10.3.9

Packages versions

N/A

Node.js version

No response

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[Kelvin-ui-hub]

Hey, let me try and work on it

[micalevisk]

@Kelvin-ui-hub go ahead. PRs are more than welcomed

[kelvin-go-get]

Okay thanks

[micalevisk]

@kamilmysliwiec can we just drop this feature in the next major release as it never worked anyway?

[kamilmysliwiec]

Sounds good @micalevisk. Would you like to create a PR for this?

[kamilmysliwiec]

#14114