Cannot upload files received using multer

[dzkb]

Hi,

first of all thanks for such a great project!

I have a very specific use case where my express.js app receives a file and then forwards it to a GraphQL API. Based on the example from the quickstart, I came up with code like this:

app.post('/endpoint', upload.single('file'), function (req, res, next) {
    let file = req.file
    const mutation = gql`
    mutation($file: Upload!){
        uploadFile(file: $file) {
            responseField
        }
    `

    request("http://localhost:8000/graphql", mutation, {
        file: file
    })
})

The problem is that when I try to run the upload (by sending a request with a file to /endpoint), graphql-request sends a JSON payload of multer's representation of the file, instead of the file itself, and my GraphQL server (Python, strawberry-based) refuses to parse that. I also tried to pass a buffer (file.buffer) instead of a file, but no luck either. Note that replacing the following part:

    request("http://localhost:8000/graphql", mutation, {
        file: file
    })

with

    request("http://localhost:8000/graphql", mutation, {
        file: createReadStream('./file'), // from fs
    })

works just fine.

I believe the underlying issue is that the FormData object, constructed before sending the request, doesn't understand multer's representation of a file. I managed to get around that by constructing my own FormData object and sending it without using graphql-request.

// graphql-multipart-request-spec related
let operations = {
  "query": mutation,
  "variables": {
    "file": null
  }
}
let requestMap = {
  "file": ["variables.file"]
}

let formData = new FormData()
formData.append("operations", JSON.stringify(operations))
formData.append("map", JSON.stringify(requestMap))
formData.append("file", file.buffer, { filename: "file", contentType: "audio/wav" }) // setting the filename and contentType seems to be enough - it's audio/wav in my case

Is this the expected behavior? Or is there any other way to pass a buffer/file to request so that graphql-reqest understand that it's actually a file?

Thanks!

[jasonkuhrt]

#500