Upload scalar return empty object as resolver argument

[mittalyashu]

Schema

scalar Upload

type Mutation {
  uploadImage(image: Upload): Image
}

Resolver

This is the resolver to import Upload scalar

const { GraphQLUpload } = require('graphql-upload');

module.exports = {
  Upload: GraphQLUpload
}

Resolver to handle image upload

const uploadImage = input => {
  const data = { ...input }
  console.log(data)

  // upload to image server
}

module.exports = {
  uploadImage
}

The Data variable return { image: {} }

[jaydenseric]

First, make sure the client is sending a valid GraphQL multipart request to the server. Use the Chrome dev tools network inspector to verify this.

Secondly, make sure the graphqlUploadKoa or graphqlUploadExpress middleware is setup correctly.

Make sure no other middleware is parsing the multipart request, particularly before the graphql-upload middleware.

[mittalyashu]

I believe the issue is not from GraphQL server instead from the resolver itself.

Though, I did check all the things you have mentioned add made the required changes for graphqlUploadExpress.

And, the problem seems still persistent.

[jaydenseric]

If in the server project you run npm ls graphql-upload, is there only one version installed? If not, you need to make sure that only one version is being used so that the middleware and scalar can work together properly.

[mittalyashu]

└── graphql-upload@11.0.0

Yup, using latest version.

Does it request to install this package in frontend (react.js project) where we use the mutation.

const mutationUploadImage = gql`
  mutation UploadImage(
    $image: Upload!
  ) {
    uploadImage(image: $image) {
      publicLink
    }
  }
`

My guess would be, when I pass the $image as variable it doesn't get sent and that's why it shows empty object in the resolver.

[jaydenseric]

You should have already verified that the front end is sending a valid GraphQL multipart request, so it is irrelevant at this point.

[mittalyashu]

I have double checked the mutation query in the frontend and there seems nothing wrong with that.

But, after inspecting the network tab, it seems it is not able to add the File blob as a variable.

[jaydenseric]

That doesn't look like a multipart request; your problem is on the client. Setup your client to send the right requests; here are a list of client implementations to choose from:

https://github.com/jaydenseric/graphql-multipart-request-spec#client