Usage

Mark provider services

Use @FactoryProvider(factoryName, providerName) on any injectable service you want to resolve through the factory.

providers/csv.service.ts

import { Injectable } from '@nestjs/common';
import { FactoryProvider } from 'nestjs-factory-pattern-module';

@Injectable()
@FactoryProvider('EXPORT_SERVICE', 'csv')
export class CsvProviderService {
  // ...
}

Inject the factory

The module exports an InjectFactory helper, which is an alias over @Inject(factoryName).

my.service.ts

import { Injectable } from '@nestjs/common';
import {
  FactoryService,
  InjectFactory,
} from 'nestjs-factory-pattern-module';

@Injectable()
export class MyService {
  constructor(
    @InjectFactory('EXPORT_SERVICE')
    private readonly factory: FactoryService<any>,
  ) {}

  async getProvider(type: string) {
    return this.factory.getProviderServiceAsync(type);
  }
}

Notes

• Provider discovery happens when FactoryService is constructed.
• If a provider is not found for a type, getProviderServiceAsync throws.