Make Angular modules easily exchangeable

Assume there are 2 feature modules "sql-connector" and "nosql-connector", which can be imported in the root module:

...
import { SqlConnectorModule } from './sql-connector/sql-connector.module';
@NgModule({ 
  ...
  imports: [ ..., SqlConnectorModule ]
  ...})
export class AppModule { }

Both feature modules are exported a connector class, that managed connection and transactions. The connector classes have similar structure, comparable to if both would implement the same interface. To apply connector class in any consumer class, we have to import the connector. The import path depends on the module .../sql-connector/connector or .../nosql-connector/connector.

Is it possible to organize code in that way, no matter if sql- or nosql-connector module is imported in app.modules.ts file, then you don't have to exchange every import directive of any consumer?

If not, is there a other pattern to make connector exchangeable with min effort and control the exchange from main/root/config file?

Provider overriding is usually used for that.

First of all, don't use modules, but services only (you shouldn't need a module if I get what the connectors are used for).

Next, declare an interface or a super class that will be common to both connectors :

declare interface IConnector {
  connect(): void;
  disconnect(): void;
}

export class ConnectorBase {
  connect() {}
  disconnect() {}
}

Implement this interface into both services :

export class SqlConnector implements IConnector {}
export class NoSqlConnector implements IConnector {}

export class SqlConnector extends ConnectorBase {
  override connect() {}
  override disconnect() {}
}
export class NoSqlConnector extends ConnectorBase {
  override connect() {}
  override disconnect() {}
}

Finally, when you want to switch, in your module, override the provider :

providers: [
  {
    provide: IConnector // ConnectorBase if it does not work with interfaces
    useClass: SqlConnector
  }
],

You can use the overriding on a per-module basis, so each module can have its own connector. If you don't provide one, then the one from app module will be used.

The other solution is to use file replacements, but it implies that a connector will be used in the whole application, and to change it, you build your application with a specific environment (ng build -c nosql-dev)

You can try making path alias for that:

// tsconfig.json
{
    "paths": {
        "@db/*": ["path/to/[sql-connector|nosql-connector]/*"]
    }
}

and

import { SqlConnectorModule } from '@db/sql-connector.module';

with that alias all you need to do is change path of alias in configuration file (dynamically or statically)