NestJS Standalone app can't inject Sequelize instance using connection token - dependency-injection

Question

I'm still quite new to NestJS. I'm trying to implement a standalone app that connect to both external/remote source DB and the app DB.
Now I got stuck at Nest can't resolve dependencies of the SourceDbQueryService (ModuleRef, ?). Please make sure that the argument {{token}} at index [1] is available in the EtlModule context.
The {{token}} here is supposedly a string returned from getConnectionToken(connectionName), ex.: sourceDbConnection when connectionName = sourceDb
Here are my modules setup example:
/src/db/source-db-module.ts
#Module({
imports: [
ConfigModule,
LoggingModule,
SequelizeModule.forRootAsync({
imports: [ConfigModule],
inject: [SourceDbConfig],
useFactory: (config: SourceDbConfig) => {
return {
...config,
name: SourceDbConfig.DefaultConnectionName,
autoLoadModels: false,
}
},
}),
],
exports: [SequelizeModule],
})
export class SourceDbModule {}
/src/jobs/etl-module.ts
#Module({
imports: [
ConfigModule,
LocalDbModule,
/** Contains Local repositories with decorated Models, using connection from LocalDbModule */
RepositoryModule,
SourceDbModule,
SequelizeModule.forFeature([], SourceDbConfig.DefaultConnectionName),
],
providers: [
{
provide: SourceDbQueryService,
inject: [ModuleRef, getConnectionToken(SourceDbConfig.DefaultConnectionName)],
useFactory(moduleRef: ModuleRef, sequelize: Sequelize) {
return new SourceDbQueryService(moduleRef, sequelize)
},
},
],
exports: [SourceDbQueryService],
})
export class EtlModule {}
/src/jobs/test-query-source-db.ts
async function bootstrap(): Promise<void> {
try {
const appContext = await NestFactory.createApplicationContext(EtlModule)
appContext.init()
const sourceDb = appContext.get(SourceDbQueryService)
const totalRecordsCount = await sourceDb.count({
// ...filters,
})
console.log(
`retrieved source DB results: (total items: ${totalItemsCount})`
)
appContext.close()
} catch (err) {
console.error(err)
process.exit(-1)
}
}
bootstrap()
Please help, what am I missing here?
Thanks!

Answer 1

Update: Workaround
For now I'm using a workaround by providing Sequelize instance directly from my own factory like this:
/src/db/source-db-module.ts
#Module({
imports: [
ConfigModule,
LoggingModule,
],
providers: [
// WORKAROUND: For SequelizeModule.forRootAsync() injection by connection token not working
{
provide: getConnectionToken(SourceDbConfig.DefaultConnectionName),
inject: [SourceDbConfig],
useFactory(config: SourceDbConfig) {
const { host, port, username, password, database, dialect } = config
return new Sequelize({
host,
port,
username,
password,
database,
dialect,
})
},
},
{
provide: SourceDbQueryService,
inject: [ModuleRef, SourceDbConfig, getConnectionToken(SourceDbConfig.DefaultConnectionName)],
useFactory(moduleRef: ModuleRef, config: SourceDbConfig, sequelize: Sequelize) {
const { schema, viewName } = config
return new SourceDbQueryService(moduleRef, sequelize, { schema, viewName })
},
},
],
exports: [
getConnectionToken(SourceDbConfig.DefaultConnectionName),
SourceDbQueryService,
],
})
export class SourceDbModule {}
/src/jobs/etl-module.ts
#Module({
imports: [
ConfigModule,
LocalDbModule,
/** Contains Local repositories with decorated Models, using connection from LocalDbModule */
RepositoryModule,
SourceDbModule,
],
})
export class EtlModule {}