Nestjs, Firebase, GCloud. TypeScript에서 API 백엔드를 빠르게 설정하는 방법

➜  my pnpm -v
9.6.0
➜  my nvm -v
0.39.2
➜  my npm -v
10.8.1
➜  my nvm ls
->     v20.16.0

...,
scripts: {
  ...,
  "lint": "eslint \"{src,apps,libs,test}/**/*.ts\"",
  "lint:fix": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix"
},
...

pnpm add -D eslint-plugin-simple-import-sort

SA_KEY=path_to_service_file

MINI_APP_URL=domain_to_mini_app # we'll leave this as a placeholder for future use.

# all env files except example
.env*
!.env.example

# google service account file (by firebase)
service-account*.json

# firebase config file
.firebaserc

# tg library local cache file
sessions.json

...
"scripts": {
  ...
  "build:prod": "NODE_ENV=production nest build",
  "start": "NODE_ENV=production nest start",
  "start:dev": "NODE_ENV=development nest start --watch"
  "start:prod": "NODE_ENV=production node dist/main"
  ...
}
...

const ENV = process.env.NODE_ENV

export const isDevelop = ENV === 'development'
export const isProduction = ENV === 'production'

export const getEnvFile = () => {
  if (isDevelop) {
    return '.env.dev'
  }

  return '.env'
}

import { Module } from '@nestjs/common'

import { AppController } from './app.controller'
import { AppService } from './app.service'
import { ConfigModule } from '@nestjs/config'
import { getEnvFile } from './env'

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true,
      envFilePath: getEnvFile(),
    }),
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

import { ConfigService } from '@nestjs/config'
import { NestFactory } from '@nestjs/core'
import * as admin from 'firebase-admin'
import * as fs from 'fs'

import { AppModule } from './app.module'

async function bootstrap() {
  const app = await NestFactory.create(AppModule)
  const configService: ConfigService = app.get(ConfigService)
  // Retrieve the service file name from the env file
  const accountPath = configService.get<string>('SA_KEY')
  // You can refine the type definitions for the service file; as you can see, I haven't focused on that yet
  const serviceAccount: any = JSON.parse(fs.readFileSync(accountPath, 'utf8'))

  const adminConfig: admin.ServiceAccount = {
    projectId: serviceAccount.project_id,
    privateKey: serviceAccount.private_key,
    clientEmail: serviceAccount.client_email,
  }

  admin.initializeApp({
    credential: admin.credential.cert(adminConfig),
    databaseURL: `https://${adminConfig.projectId}.firebaseio.com`,
  })

  // The port value can also be moved to the env file if needed; I’ve skipped this step
  await app.listen(8080)
}

bootstrap()

// firestore.providers.ts
export const FirestoreDatabaseProvider = 'firestoredb'
export const FirestoreOptionsProvider = 'firestoreOptions'
export const FirestoreCollectionProviders: string[] = [/* Next, you will need to add classes for Firestore collection documents.
 */]

// types.ts
// Add a type for typing the module arguments
import { Settings } from '@google-cloud/firestore'

export type FirestoreModuleOptions = {
  imports: any[]
  useFactory: (...args: any[]) => Settings
  inject: any[]
}

// firestore.module.ts
// Here, we are creating our own module provider for Firestore collections
import { Firestore } from '@google-cloud/firestore'
import { DynamicModule, Module } from '@nestjs/common'

import {
  FirestoreCollectionProviders,
  FirestoreDatabaseProvider,
  FirestoreOptionsProvider,
} from './firestore.providers'
import { FirestoreModuleOptions } from './types'

@Module({})
export class FirestoreModule {
  static forRoot(options: FirestoreModuleOptions): DynamicModule {
    const collectionProviders = FirestoreCollectionProviders.map((providerName) => ({
      provide: providerName,
      useFactory: (db) => db.collection(providerName),
      inject: [FirestoreDatabaseProvider],
    }))

    const optionsProvider = {
      provide: FirestoreOptionsProvider,
      useFactory: options.useFactory,
      inject: options.inject,
    }

    const dbProvider = {
      provide: FirestoreDatabaseProvider,
      useFactory: (config) => new Firestore(config),
      inject: [FirestoreOptionsProvider],
    }

    return {
      global: true,
      module: FirestoreModule,
      imports: options.imports,
      providers: [optionsProvider, dbProvider, ...collectionProviders],
      exports: [dbProvider, ...collectionProviders],
    }
  }
}

...
import { ConfigModule, ConfigService } from '@nestjs/config'
...
import { FirestoreModule } from './providers'
...

@Module({
  imports: [
    FirestoreModule.forRoot({
      imports: [ConfigModule],
      useFactory: (configService: ConfigService) => ({
        keyFilename: configService.get<string>('SA_KEY'),
      }),
      inject: [ConfigService],
    }),
  ],
  ...
})

src/modules
  - example
    - repositories
      - example.repository.ts
      - index.ts
    - controllers
      - example.controller.ts
      - index.ts
    - services
      - example.service.ts
      - index.ts
    - entities
      - example.document.ts
      - index.ts
    - dto
      - example.request.ts
      - example.response.ts
      - index.ts
    example.module.ts
helpers
  - time.ts
  - id.ts
  - index.ts

// time.ts
import * as dayjs from 'dayjs'
import * as duration from 'dayjs/plugin/duration'
import * as isToday from 'dayjs/plugin/isToday'
import * as timezone from 'dayjs/plugin/timezone'
import * as utc from 'dayjs/plugin/utc'

// In general, you can do without all of this; it depends on your project. I left it as an example.

dayjs.extend(utc)
dayjs.extend(timezone)
dayjs.extend(isToday)
dayjs.extend(duration)

export const time = dayjs

// id.ts
import { v4 } from 'uuid'

const getUniqueId = (): string => v4()

export { getUniqueId }

// example/entities/example.document.ts
import { Timestamp } from '@google-cloud/firestore'

export class ExampleDocument {
  static collectionName = 'example'

  id: string
  title: string
  text?: string | null
  isPublished: boolean
  createdAt?: Timestamp | null
  updatedAt?: Timestamp | null
}

// example/dto/example.filter.ts
export class ExampleFilter {
  public isPublished?: boolean
}

// example/dto/example.request.ts
export class ExampleRequestBody {
  public title: string
  public text?: string
}

// example/dto/example.response.ts
export class ExampleResponseItem {
  public id: string
  public title: string
  public text?: string | null
  public isPublished: boolean
  public createdAt?: string | null
  public updatedAt?: string | null
}

// example/controllers/example.controller.ts
import { Body, Controller, Get, NotFoundException, Param, Patch, Post, Query } from '@nestjs/common'

import { ExampleFilter, ExampleRequestBody } from '../dto'
import { ExampleDocument } from '../entities'
import { ExampleService } from '../services'

@Controller('v1/example')
export class ExampleController {
  constructor(private readonly exampleService: ExampleService) {}

  @Get('/')
  async getList(@Query() query?: ExampleFilter): Promise<ExampleDocument[]> {
    const response = await this.exampleService.getList(query)

    if (!response?.length) {
      throw new NotFoundException('Examples are not exist')
    }

    return response
  }

  @Get('/:id')
  async get(@Param('id') id: string): Promise<ExampleDocument> {
    const response = await this.exampleService.getItem(id)

    if (!response) {
      throw new NotFoundException('Example does not exist')
    }

    return response
  }

  @Post('/')
  async create(@Body() body: ExampleRequestBody): Promise<ExampleDocument> {
    return this.exampleService.create(body)
  }

  @Patch('/:id')
  async update(@Param('id') id: string, @Body() body: ExampleRequestBody): Promise<ExampleDocument> {
    return this.exampleService.update(id, body)
  }

  @Patch('/publish/:id')
  async togglePublish(@Param('id') id: string): Promise<ExampleDocument> {
    return this.exampleService.togglePublish(id)
  }
}

// example/services/example.service.ts

import { Injectable, NotFoundException } from '@nestjs/common'

import { ExampleFilter, ExampleRequestBody } from '../dto'
import { ExampleRepository } from '../repositories'

@Injectable()
export class ExampleService {
  constructor(private readonly exampleRepository: ExampleRepository) {}

  public async getList(filter: ExampleFilter) {
    return this.exampleRepository.find(filter)
  }

  public async getItem(id: string) {
    return this.exampleRepository.getDataByDocumentId(id)
  }

  public async create(body: ExampleRequestBody) {
    return this.exampleRepository.create(body)
  }

  public async update(id: string, body: ExampleRequestBody) {
    const { doc, data } = await this.exampleRepository.getUpdate(id)

    if (!doc || !data) {
      throw new NotFoundException('Example document does not exist')
    }

    const response = this.exampleRepository.getValidProperties({ ...data, ...body }, true)
    const changedKeys = Object.keys(body)
    const valuesToUpdate: Partial<ExampleRequestBody> = {}

    for (const key of changedKeys) {
      const newValue = response?.[key]
      const currentValue = doc?.[key]

      if (newValue !== currentValue) {
        valuesToUpdate[key] = newValue
      }
    }

    if (Object.keys(valuesToUpdate).length > 0) {
      await doc.update({ ...valuesToUpdate, updatedAt: response?.updatedAt })
    }

    return response
  }

  public async togglePublish(id: string) {
    const { doc, data } = await this.exampleRepository.getUpdate(id)

    if (!doc || !data) {
      throw new NotFoundException('Example document does not exist')
    }

    const newPublishedState = !data?.isPublished

    const response = this.exampleRepository.getValidProperties({ ...data, isPublished: newPublishedState }, true)

    await doc.update({ isPublished: newPublishedState, updatedAt: response?.updatedAt })

    return response
  }
}

// example/repositories/example.repository.ts

import { CollectionReference, Query, Timestamp } from '@google-cloud/firestore'
import { Inject, Injectable, Logger } from '@nestjs/common'
import { getUniqueId, time } from 'src/helpers'

import { ExampleFilter } from '../dto'
import { ExampleDocument } from '../entities'

@Injectable()
export class ExampleRepository {
  private logger: Logger = new Logger(ExampleRepository.name)

  constructor(
    @Inject(ExampleDocument.collectionName)
    private collection: CollectionReference<ExampleDocument>,
  ) {}

  async getDataByDocumentId(id: string): Promise<ExampleDocument | null> {
    const snapshot = await this.collection.doc(id).get()

    if (!snapshot.exists) {
      return null
    } else {
      return snapshot.data()
    }
  }

  /**
  * The method returns the document value and additional methods for working with the collection document, with a particular focus on the .update(...props) method.
  **/
  async getUpdate(id: string) {
    const doc = await this.collection.doc(id)
    const snapshot = await doc.get()

    if (!snapshot.exists) {
      return { doc: null, data: null }
    } else {
      return { doc, data: snapshot.data() }
    }
  }

  /**
  * Essentially, this method will handle adding new filters to the collection query.
  * At the moment, it only uses the `isPublished` flag.
  **/
  private findGenerator(filter: ExampleFilter) {
    const collectionRef = this.collection
    let query: Query<ExampleDocument> = collectionRef

    if (typeof filter?.isPublished === 'boolean') {
      query = query.where('isPublished', '==', filter.isPublished)
    }

    return query
  }

  async find(filter: ExampleFilter): Promise<ExampleDocument[]> {
    const list: ExampleDocument[] = []
    const query = this.findGenerator(filter)

    const snapshot = await query.get()

    snapshot.forEach((doc) => list.push(doc.data()))

    return list
  }

  async create(payload: Pick<ExampleDocument, 'title'> & Partial<ExampleDocument>) {
    const validPayload = this.getValidProperties(payload)
    const document = await this.collection.doc(validPayload.id)
    await document.set(validPayload)

    return validPayload
  }

  /**
  * This method is needed to prepare data before writing to Firestore.
  * The input document may be missing an ID and other fields, so we provide fallback values and set document timestamps.
  * The `newUpdatedAt` flag is used to set the current date in the `updatedAt` field.
  **/
  public getValidProperties(
    document: Omit<ExampleDocument, 'id' | 'isPublished'> & { id?: string; isPublished?: boolean | null },
    newUpdatedAt = false,
  ) {
    const dueDateMillis = time().valueOf()
    const createdAt = Timestamp.fromMillis(dueDateMillis)

    return {
      id: document.id || getUniqueId(),
      title: document.title,
      text: document.text ?? null,
      isPublished: document.isPublished ?? false,
      createdAt: document.createdAt ?? createdAt,
      updatedAt: newUpdatedAt ? createdAt : (document.updatedAt ?? null),
    }
  }
}

// example/index.ts
export * from './entities'
export * from './example.module'

// firebase.provider.ts
import { ExampleDocument } from 'src/modules/example'

...

// In this way, we add the document to the list of Firestore collections for working with `ExampleDocument`.
// In the future, you will need to add other new Firestore collections here.
export const FirestoreCollectionProviders: string[] = [ExampleDocument.collectionName]

...
import { ExampleModule } from './modules/example'
...

@Module({
  imports: [
    ...,
    ExampleModule,
  ],
  ...
})
export class AppModule {}

":{"code":403,"message":"Read access to project 'nestjs-boilerplate-example' was denied: please check billing account associated and retry","status":"PERMISSION_DENIED"}}
[2024-07-28T18:40:19.841Z] error getting database typeHTTP Error: 403, Read access to project 'nestjs-boilerplate-example' was denied: please check billing account associated and retry {"name":"FirebaseError","children":[],"context":{"body":{"error":{"code":403,"message":"Read access to project 'nestjs-boilerplate-example' was denied: please check billing account associated and retry","status":"PERMISSION_DENIED"}},"response":{"statusCode":403}},"exit":1,"message":"HTTP Error: 403, Read access to project 'nestjs-boilerplate-example' was denied: please check billing account associated and retry","status":403}
[2024-07-28T18:40:19.842Z] database_type: undefined

...
"scripts": {
  ...,
  "prepare": "node .husky/install.mjs"
}

// Skip Husky install in production and CI
if (process.env.NODE_ENV === 'production' || process.env.CI === 'true') {
  process.exit(0)
}
const husky = (await import('husky')).default
console.log(husky())

pnpm run lint-staged && pnpm run lint:fix

...
"scripts": {
  ...,
  "lint-staged": "lint-staged --allow-empty",
},
"lint-staged": {
  "*.{js,jsx,ts,tsx}": [
    "pnpm lint --fix"
  ]
}
...

{ isPublished: 'false' }

// Instead of
if (typeof filter?.isPublished === 'boolean') {
  query = query.where('isPublished', '==', filter.isPublished)
}

// Something like this
if (filter?.isPublished) {
  const isPublished = filter?.isPublished === 'true' ? true : false
  query = query.where('isPublished', '==', isPublished)
}

// example/controllers/example.controller.ts
import {
  ...,
  ParseBoolPipe,
  ...,
} from '@nestjs/common'
...
  @Get('/')
  async getList(@Query('isPublished', ParseBoolPipe) isPublished?: boolean): Promise<ExampleDocument[]> {
    const response = await this.exampleService.getList({ isPublished })
    // ...
  }
...

// repositories/example.repository.ts

...
  async find(filter: ExampleFilter): Promise<ExampleDocument[]> {
    ...
    let query = this.findGenerator(filter)

    query = query.orderBy('createdAt', 'desc')
    ...
  }
...

9 FAILED_PRECONDITION: The query requires an index. You can create it here: <url>

// firestore.indexes.json
{
  "indexes": [
    {
      "collectionGroup": "example",
      "queryScope": "COLLECTION",
      "fields": [
        {
          "fieldPath": "isPublished",
          "order": "ASCENDING"
        },
        {
          "fieldPath": "createdAt",
          "order": "DESCENDING"
        }
      ]
    }
  ],
  "fieldOverrides": []
}

src/providers
  - bucket
    - providers
      default.bucket.ts
      index.ts
    bucket.constants.ts
    bucket.module.ts
    bucket.providers.ts
    bucket.shared.service.ts
    bucket.types.ts
    index.ts
    utils.ts

// default.bucket.ts
export class DefaultBucketProvider {
  static bucketName = 'default'
}

// bucket.constants.ts
export const getDefaultOptions = (role: string) => ({
  entity: 'allUsers',
  role: role,
})

// bucket.providers.ts
import { DefaultBucketProvider } from './providers'

export const StorageBucketsProvider = 'StorageBucketsProvider'
export const StorageOptionsProvider = 'StorageOptionsProvider'

export const StorageBucketProviders: string[] = [DefaultBucketProvider.bucketName]

// bucket.types.ts
import { Bucket, Storage } from '@google-cloud/storage'

export type StorageProps = {
  keyFilename: string
}

export type FirestoreModuleOptions = {
  imports: any[]
  useFactory: (...args: any[]) => StorageProps
  inject: any[]
}

export type BucketProvider = {
  bucket: Bucket
  storage: Storage
}

// bucket.shared.service.ts
import { Bucket } from '@google-cloud/storage'
import { Logger } from '@nestjs/common'
import { extname } from 'path'

export class BucketSharedService {
  private bucket: Bucket
  private logger: Logger

  constructor(bucket: Bucket, logName?: string) {
    this.bucket = bucket
    this.logger = new Logger(`${BucketSharedService.name}_${logName}`)
  }

  public async isFileExists(name: string) {
    try {
      const fileName = name
      const file = this.bucket.file(fileName)

      const [isExists] = await file.exists()

      return isExists
    } catch (error) {
      throw error
    }
  }

  public async deleteFileByName(path: string, folderPath: string) {
    return new Promise(async (resolve, reject) => {
      const pathes = path?.includes('%2F') ? path?.split('%2F') : path?.split('/')
      const fileName = pathes?.[pathes?.length - 1]
      const file = this.bucket.file(`${folderPath ? `${folderPath}/` : ''}${fileName}`)

      const [isExists] = await file.exists()

      if (!isExists) {
        reject(new Error('File does not exist'))
      }

      /**
       * There are no guarantees that it definitely deletes, but it seems that files become inaccessible for search by their links
       */
      file
        .delete()
        .then((res) => {
          resolve(res)
        })
        .catch((err) => {
          this.logger.error('Error with file bucket removing', err?.message)
          reject(err)
        })
    })
  }

  /**
   * Using with internal upload folders
   */
  public async saveFileByUploadsFolder(definedFile: Express.Multer.File, folderPath?: string): Promise<string> {
    const uniqueSuffix = `${folderPath || 'main'}/${Date.now()}-${Math.round(Math.random() * 1e9)}`
    const fileName = `${uniqueSuffix}${extname(definedFile.path)}`

    return new Promise((resolve, reject) => {
      this.bucket
        .upload(definedFile.path, {
          destination: fileName,
        })
        .then((response) => {
          const [uploadedFile] = response || []
          const file = this.bucket.file(uploadedFile?.metadata?.name)

          file.makePublic(async (err) => {
            if (err) {
              this.logger.error(`Error making file public: ${err}`)
              reject(err)
            } else {
              this.logger.log(`File ${file.name} is now public.`)
              const publicUrl = file.publicUrl()
              this.logger.log(`Public URL for ${file.name}: ${publicUrl}`)
              resolve(publicUrl)
            }
          })

          return true
        })
        .catch((err) => {
          reject(err)
        })
    })
  }

  /**
   * Using without multer storage option, only memory buffer
   */
  public async saveFileByUrlAndBuffer(path: string, folderPath: string, buffer: Buffer): Promise<string> {
    return new Promise(async (resolve, reject) => {
      const uniqueSuffix = `${folderPath || 'main'}/${Date.now()}-${Math.round(Math.random() * 1e9)}`
      const fileName = `${uniqueSuffix}${extname(path)}`
      const file = this.bucket.file(fileName)
      await file.save(buffer)

      file.makePublic(async (err) => {
        if (err) {
          this.logger.error(`Error making file public: ${err}`)
          reject(err)
        } else {
          this.logger.log(`File ${file.name} is now public.`)
          const publicUrl = file.publicUrl()
          this.logger.log(`Public URL for ${file.name}: ${publicUrl}`)
          resolve(publicUrl)
        }
      })
    })
  }
}

// bucket.module.ts
import { Storage } from '@google-cloud/storage'
import { DynamicModule, Module } from '@nestjs/common'
import * as fs from 'fs'

import { getDefaultOptions } from './bucket.constants'
import { StorageBucketProviders, StorageBucketsProvider, StorageOptionsProvider } from './bucket.providers'
import { FirestoreModuleOptions, StorageProps } from './bucket.types'

@Module({})
export class BucketModule {
  static forRoot(options: FirestoreModuleOptions): DynamicModule {
    const bucketProviders = StorageBucketProviders.map((providerName) => ({
      provide: providerName,
      useFactory: async (storage: Storage) => {
        console.log(storage, 'storage')
        /**
         * Use default bucket name
         */
        const bucket = storage.bucket(providerName === 'default' ? `${storage.projectId}.appspot.com` : providerName)

        const [isExist] = await bucket.exists()

        /**
         * Basic steps to create public bucket with writer rules, available only for BLAZE price
         */
        if (!isExist) {
          const options = getDefaultOptions(storage.acl.WRITER_ROLE)

          await bucket.create().catch((err) => console.error(`bucket ${providerName} creation get error`, err))

          console.info(`bucket ${providerName} created successfully`)

          bucket.acl.add(options, (err) => {
            if (!err) {
              console.info(`acl added successfully to ${providerName} bucket`)
            } else {
              console.error(`bucket ${providerName} error`, err)
            }
          })
        }

        return { bucket, storage }
      },
      inject: [StorageBucketsProvider],
    }))

    const optionsProvider = {
      provide: StorageOptionsProvider,
      useFactory: options.useFactory,
      inject: options.inject,
    }

    const provider = {
      provide: StorageBucketsProvider,
      useFactory: (config: StorageProps) => {
        const serviceAccount: { project_id?: string } = JSON.parse(fs.readFileSync(config.keyFilename, 'utf8'))

        return new Storage({ ...config, projectId: serviceAccount.project_id ?? '' })
      },
      inject: [StorageOptionsProvider],
    }

    return {
      global: true,
      module: BucketModule,
      imports: options.imports,
      providers: [optionsProvider, provider, ...bucketProviders],
      exports: [provider, ...bucketProviders],
    }
  }
}

// utils.ts
import { diskStorage } from 'multer'
import { extname } from 'path'

export const storage = diskStorage({
  destination: './uploads',
  filename: (_, file, cb) => {
    // Proposed file name regeneration
    const uniqueSuffix = `${Date.now()}-${Math.round(Math.random() * 1e9)}`
    cb(null, `${uniqueSuffix}${extname(file.originalname)}`)
  },
})

// index.ts - for short imports
export * from './bucket.module'
export * from './bucket.shared.service'
export * from './bucket.types'
export * from './providers'
export * from './utils'

// app.module.ts
...

@Module({
  imports: [
    ...
    BucketModule.forRoot({
      imports: [ConfigModule],
      useFactory: (configService: ConfigService) => ({
        keyFilename: configService.get<string>('SA_KEY'),
      }),
      inject: [ConfigService],
    }),
  ],
  ...
})
export class AppModule {}

- helpers
  ...
  - fileValidation
    constants.ts
    utils.ts
    index.ts

// constants.ts
export const listDefaultImageExt = 'image/png,image/jpeg,image/webp'

export const listPngAndJpegImageExt = 'image/png,image/jpeg'

export const IMG_MAX_SIZE_IN_BYTE = 716800 // 700kb

export const IMG_MAX_1MB_SIZE_IN_BYTE = 1048576 // 1mb

export const IMG_MAX_5MB_SIZE_IN_BYTE = 1048576 * 5 // 1mb

// utils.ts
import { reduce } from 'lodash'

export const getFileTypesRegexp = (ext: string): string => reduce(ext.split(','), (acc, key) => `${acc}|${key}`)

// example/controllers/example.controller.ts
...

@Post('/:id/image')
@UseInterceptors(FileInterceptor('file', { storage, limits: { files: 1 } }))
async updateExampleImage(
  @UploadedFile(
    new ParseFilePipe({
      validators: [
        new MaxFileSizeValidator({ maxSize: IMG_MAX_1MB_SIZE_IN_BYTE }),
        new FileTypeValidator({ fileType: getFileTypesRegexp(listPngAndJpegImageExt) }),
      ],
    }),
  )
  file: Express.Multer.File,
  @Param('id') id: string,
): Promise<ExampleDocument> {
  return this.exampleService.updateImage(id, file)
}
...

// example/services/example.service.ts
...
export class ExampleService {
  private bucketService: BucketSharedService

  constructor(
    private readonly exampleRepository: ExampleRepository,
    @Inject(DefaultBucketProvider.bucketName)
    private readonly bucketProvider: BucketProvider,
  ) {
    this.bucketService = new BucketSharedService(this.bucketProvider.bucket, ExampleService.name)
  }
...
  public async updateImage(id: string, file: Express.Multer.File) {
    try {
      const { doc, data } = await this.exampleRepository.getUpdate(id)

      if (!doc || !data) {
        throw new NotFoundException('Example document does not exist')
      }

      const imageUrl = await this.bucketService.saveFileByUploadsFolder(file, `example/${data?.id}`)

      // It is possible to add deletion through an additional check if (data?.imageUrl, but in general this is not necessary, for the case when the file is missing, we definitely wrap the delete method call in a try-catch block)
      try {
        /**
         * Try to remove previously file
         */
        await this.bucketService.deleteFileByName(data?.imageUrl, `example/${data?.id}`)
      } catch {}

      const response = this.exampleRepository.getValidProperties({ ...data, imageUrl }, true)

      await doc.update({ imageUrl, updatedAt: response?.updatedAt })

      /**
       * Need for deletion uploads file by file.path
       */
      fs.unlinkSync(file.path)

      return response
    } catch (error) {
      /**
       * Need for deletion uploads/ file path
       */
      fs.unlinkSync(file.path)

      throw error
    }
  }
...
}