Upload scalar support for the schema wrapping

[mikeconley12]

Is your feature request related to a problem? Please describe.

I'm using @graphql-tools/wrap@7.0.5 package with graphql-upload@9.0.0. And I have code similar to this:

const wrappedSchema = wrapSchema({
  schema,
  transforms: [
    new RenameTypes(name => {
      // ...
    }),
  ],
})

The schema has the Upload scalar from the graphql-upload package. When I run my code I have the following error: Error: ‘Upload’ scalar serialization unsupported.. The serialize method is called by the wrapSchema function.

Please see the links:

1. graphql-tools/packages/utils/src/transformInputValue.ts

   Line 44 in 75fe51f

   return transformInputValue(type, value, (t, v) => t.serialize(v));

2. graphql-tools/packages/delegate/src/createRequest.ts

   Line 110 in 75fe51f

   const serializedValue = serializeInputValue(varType, variableValues[varName]);

Describe the solution you'd like

Is it possible to avoid calling the serialize method when using the wrapSchema function? Or is there another solution?

Describe alternatives you've considered

I defined my own version of the Upload scalar:

const GraphQLUpload = new GraphQLScalarType({
  name: 'Upload',
  description: 'The `Upload` scalar type represents a file upload.',
  parseValue: (value: any) => value,
  parseLiteral () {
    throw new Error('‘Upload’ scalar literal unsupported.')
  },
  serialize (value) {
    return value
  },
})

This solved the error, but it doesn't seem safe

Additional context

My Node.js version is v14.16.0 and I'm using Ubuntu 20.04

[ardatan]

@mikeconley12 Maybe this helps you?
https://github.com/ardatan/graphql-tools/blob/master/packages/links/src/GraphQLUpload.ts

[mikeconley12]

@ardatan thanks for your answer! But is it safe to just return the value from the serialize method? Original GraphQLUpload throws an error in the serialize method

[ardatan]

@mikeconley12 It is passed internally to the subschema so I don't think it is unsafe. @yaacovCR What do you think?

[yaacovCR]

jaydenseric/graphql-upload#194

@jaydenseric has some valid reasons for not changing the scalar. He suggests a workaround over there for us to avoid “serializing” the scalar using the normal method, which I don’t find terribly appealing.

I think this might relate to a broader graphql discussion about whether there could be a way to mark a scalar (or enum) as only valid for input (or output).

Our present options are to take up his extensions suggestion or just encourage users to use our version of the scalar without the serialize check. Its perfectly safe, you just have to remember on your own to not use the upload scalar as output.

[mikeconley12]

Thank you for the answers!