custom-repository.ts

import { BaseFirestoreRepository, CustomRepository } from 'fireorm';
import Band from './models/Band';

@CustomRepository(Band)
class BandRepository extends BaseFirestoreRepository<Band> {
  async getProgressiveRockBands(): Promise<Band[]> {
    return this.whereArrayCointain('genres', 'progressive-rock').find();
  }
}

const bandRepository = getRepository(Band);
const bands = await bandRepository.getProgressiveRockBands();