用NestJ和ValidationPipe在GraphQL中上传

Question

我试图使用以下策略：https://stephen-knutter.github.io/2020-02-07-nestjs-graphql-file-upload/在我的api中进行文件上传。

如果不使用ValidationPipe，但是当我启用ValidationPipe时，类转换器上会出现这样的错误：

TypeError: Promise resolver undefined is not a function
    at new Promise (<anonymous>)
    at TransformOperationExecutor.transform (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/TransformOperationExecutor.js:117:32)
    at _loop_1 (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/TransformOperationExecutor.js:235:45)
    at TransformOperationExecutor.transform (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/TransformOperationExecutor.js:260:17)
    at ClassTransformer.plainToClass (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/ClassTransformer.js:17:25)
    at Object.plainToClass (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/index.js:20:29)
    at ValidationPipe.transform (/Users/victorassis/Workspace/barreiroclub/api/node_modules/@nestjs/common/pipes/validation.pipe.js:40:39)
    at /Users/victorassis/Workspace/barreiroclub/api/node_modules/@nestjs/core/pipes/pipes-consumer.js:15:33
    at processTicksAndRejections (internal/process/task_queues.js:97:5)

我搜索了很多，但是像类转换器这样的搜索被放弃了，答案是不要在上传的时候使用ValidationPipe。

有人认错了然后找到了解决办法？

Answer 1

我试着遵循您上面发布的示例，然后启用类的转换，正如您所提到的，我没有遇到任何错误。但是，当我试图在解析器中放置错误类型的参数时，我遇到了这个错误。下面是我安装应用程序引导程序的地方：

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.enableCors({
    origin: extractOrigins(app.get(ConfigService).get('CORS_ORIGINS')),
  });
  app.useGlobalPipes(
    new ValidationPipe({
      transform: true,
    }),
  );
  app.use(graphqlUploadExpress());
  await app.listen(app.get(ConfigService).get('PORT') ?? 3000);

  logScaffoldApp(app);
}
bootstrap();

解析程序代码：

@Mutation(() => Boolean, { nullable: true })
  async uploadVocabularies(
    @Args({
      name: 'file',
      type: () => GraphQLUpload,
    })
    { createReadStream, filename }: FileUpload,
  ) {
    console.log('attachment:', filename);

    const stream = createReadStream();
    stream.on('data', (chunk: Buffer) => {
      console.log(chunk);
    });
  }

当我尝试学习另一个教程时，我确实得到了一个错误，并且尝试将这个论点作为一个承诺，所以类转换器得到了同样的错误：

@Mutation(() => Boolean, { nullable: true })
  async uploadVocabularies(
    @Args({
      name: 'file',
      type: () => GraphQLUpload,
    })
    attachment: Promise<FileUpload>,
  ) {
    const { filename, createReadStream } = await attachment;
    console.log('attachment:', filename);

    const stream = createReadStream();
    stream.on('data', (chunk: Buffer) => {
      console.log(chunk);
    });
  }

我希望这能帮助你和其他看过这篇文章的人