Cant use mikro-orm's v6.4 feature of having multiple configs within mikro-orm.config.ts

[yawhide]

Describe the bug
Mikro-orm v6.4 has a new feature where you can define multiple configs within mikro-orm.config.ts and then reference each one using contextName.
This enables great synergy with their cli tool so that you can reference which context you want to use in a single config file (something like this: npx mikro-orm --contextName=super).

When I try to set this up following their example, i get an error:
error: No driver specified, please fill in the `driver` option or use `defineConfig` helper (to define your ORM config) or `MikroORM` class (to call the `init` method) exported from the driver package (e.g. `import { defineConfig } from '@mikro-orm/mysql'; export defineConfig({ ... })`).

This problem is forcing me to have a multi config setup (aka something like mikro-orm.super.config.ts and mikro-orm.mini.config.ts) and makes setting up the cli less dev friendly.

To Reproduce
Steps to reproduce the behavior:

in mikro-orm.config.ts

import { defineConfig } from '@mikro-orm/postgresql';

export default [
  defineConfig({
    contextName: 'mini',
    // other settings
  }),
  defineConfig({
    contextName: 'super',
    // other settings
  }),

In app.module.ts

import mikroOrmConfigfrom "./mikro-orm.config";

MikroOrmModule.forRoot(mikroOrmConfig)

In some.service.ts

import { OnModuleInit } from "@nestjs/common";

@Injectable()
export class SomeService implements OnModuleInit {

constructor(
@InjectEntityManager("super") private readonly em: EntityManager
)

...

When I try to run my app, I get the error I posted above.

Expected behavior
Be able to have all my configs in a single file.

Dependency	Version
node	v20
typescript	5.5
mikro-orm/core	6.4
mikro-orm/nestjs	6.0.2
your-driver	postgresql driver

---

let me know if you cant reproduce this issue and it is an issue on my end. thanks!

[B4nan]

I don't think it can work the way you do it. forRoot needs to have a single confix, and you are feeding it an array. To have multiple ORM instances, you would need multiple forRoot calls.

But I guess we could expand the calls automatically if we see it's an array. Thoughts @boenrobot?

[yawhide]

I don't think it can work the way you do it. forRoot needs to have a single confix, and you are feeding it an array. To have multiple ORM instances, you would need multiple forRoot calls.

But I guess we could expand the calls automatically if we see it's an array. Thoughts @boenrobot?

that explains it. what is nice about mikro-orm supporting multiple configs in a single config file is that it plays well with the rest of their ecosystem. even in nestjs, in my app.module.ts, i could do:

MikroOrmModule.forRoot()

and 'nestjs just magically works' with multiple configs. then i select which context in my services.

[B4nan]

Hmm, I guess we would still need a bit different approach, since forRoot needs to return a nest module, not multiple, just one.

[yawhide]

Hmm, I guess we would still need a bit different approach, since forRoot needs to return a nest module, not multiple, just one.

ah i see.

[B4nan]

I guess we can have two signatures and users would just need to restructure the return value.