You need to provide explicit type for 'file' of 'InputType' class. | Type-graphql

Question

I try to create a GraphQL endpoint, where I can upload a file.

In my resolver I get as arguments context and data with a custom type

import { ReturnType, InputType } from '@pkg/schemas'
import { Context } from '@pkg/types'
import { GraphQLUpload } from 'graphql-upload'

...
  @Mutation(() => ReturnType)
  uploadFileAndData(
    @Ctx() ctx: Context,
    @Arg('data', () => GraphQLUpload, { description: 'File Upload' }) data: InputType,
  ): Promise<ReturnType> {
    return functionWithMagic({ ctx, data })
  }

My input type looks like:

import { FileUpload } from 'graphql-upload'

...
@InputType({ description: 'Upload data input' })
export class InputType {
  @Field({
    nullable: true,
    description: 'File upload',
  })
  @Joiful.any()
  file: FileUpload
}

But when I try to run my code I get an error message:

Error: Unable to infer GraphQL type from TypeScript reflection system. You need to provide explicit type for 'file' of 'InputType' class.

Answer 1

To fix this issue I changed following

  @Mutation(() => ReturnType)
  uploadFileAndData(
    @Ctx() ctx: Context,
    @Arg('data', { description: 'File Upload' }) data: InputType,
  ): Promise<ReturnType> {
    return functionWithMagic({ ctx, data })
  }

and in my ReturnType I added

import { FileUpload, GraphQLUpload } from 'graphql-upload'

...
@InputType({ description: 'Upload data input' })
export class InputType {
  @Field(() => GraphQLUpload)
  @Joiful.any()
  file: FileUpload
}