Incompatibility of ValidationPipe with graphql-upload

[VictorAssis]

Bug Report

Current behavior

When i create a DTO for my mutation having a FileUpload field and binding the ValidationPipe, i get the error:

TypeError: Promise resolver undefined is not a function
    at new Promise (<anonymous>)
    at TransformOperationExecutor.transform (/Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/class-transformer/TransformOperationExecutor.js:117:32)
    at _loop_1 (/Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/class-transformer/TransformOperationExecutor.js:235:45)
    at TransformOperationExecutor.transform (/Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/class-transformer/TransformOperationExecutor.js:260:17)
    at ClassTransformer.plainToClass (/Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/class-transformer/ClassTransformer.js:17:25)
    at Object.plainToClass (/Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/class-transformer/index.js:20:29)
    at ValidationPipe.transform (/Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/@nestjs/common/pipes/validation.pipe.js:41:39)
    at /Users/victorassis/Workspace/barreiroclub/nestjs-graphql-upload-error/node_modules/@nestjs/core/pipes/pipes-consumer.js:16:33
    at processTicksAndRejections (internal/process/task_queues.js:97:5)

Input Code

I created the repo https://github.com/VictorAssis/nestjs-graphql-upload-error with a resolver called CategoriesResolver that demonstrates the upload working witthout ValidationPipe and with ValidationPipe but without DTO and the case when occurs error (with ValidationPipe and with DTO).

// CategoriesResolver
@Mutation(returns => String)
  @UsePipes(ValidationPipe)
  async createWithDtoWithValidation (@Args() newCategory: NewCategoryInput) {
    const file = await newCategory.file
    return `It does not work ${file.filename}`
  }

// NewCategoryInput
@ArgsType()
export class NewCategoryInput {
  @Field()
  @IsString()
  @MinLength(3, { message: 'Name too short.' })
  name: string;

  @Field(type => GraphQLUpload)
  file: FileUpload
}

Expected behavior

Receive the Promise in my resolver as when I'm not using ValidationPipe.

Possible Solution

I tried to set transform: false in the ValidationPipe options but was ignored.

Another attempt was to set @Exclude for the property in the DTO, but the property did not come in the resolver method.

Environment

Nest version: 7.0.0

[kamilmysliwiec]

Please, report this issue here https://github.com/typestack/class-transformer/pulls