NestJS + TypeScript + GraphQL でファイルをアップロードする

npm i graphql-upload-ts

import { Args, Mutation, Resolver } from '@nestjs/graphql';
import { createWriteStream } from 'fs';
import { FileUpload, GraphQLUpload } from 'graphql-upload-ts';
import { existsSync, mkdirSync } from 'fs';

@Resolver()
export class UploaderResolver {
  @Mutation(() => Boolean)
  async singleUpload(
    @Args({ name: 'file', type: () => GraphQLUpload })
    { createReadStream, filename }: FileUpload,
  ) {
    const writeDirName = './stores';
    if (!existsSync(writeDirName)) {
      mkdirSync(writeDirName);
    }

    return new Promise((resolve, reject) => {
      createReadStream()
        .pipe(createWriteStream(`${writeDirName}/${filename}`))
        .on('finish', () => {
          console.log('完了しました。');
          resolve(true);
        })
        .on('error', (error) => {
          console.error('File write error:', error);
          reject(false);
        });
    });
  }
}

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { ConfigService } from '@nestjs/config';
import { ValidationPipe } from '@nestjs/common';
import { graphqlUploadExpress } from 'graphql-upload-ts';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  const configService = app.get(ConfigService);
  const appPort = configService.get<number>('app.port');
  app.useGlobalPipes(new ValidationPipe());

  app.use(graphqlUploadExpress());
  await app.listen(appPort);

  console.log(`App is running on: ${await app.getUrl()}`);
}
bootstrap();

mutation singleUpload($file: Upload!) {
  singleUpload(file: $file)
}

{"file": Upload}