[Issue]: InputValidationError returns text/plain but should return application/json about wundergraph

[Pagebakers]

Thanks for looking into this @anothermh , I've opened in internal issue to go over this.

[Pagebakers]

Thanks for the elaborate report, this seems to be incorrect indeed. Have you also looked into a possible fix?

[anothermh]

I've tried a number of different fixes where I use w.Header().Set("Content-Type", "application/json") prior to the error response (or any response) being sent but it never seems to stick. For example, I thought this block might be where to set the header but that wasn't it:

wundergraph/pkg/apihandler/errorhandler.go

Lines 101 to 109 in 38c73f9

	var validationError *inputvariables.ValidationError
	if errors.As(err, &validationError) {
	w.WriteHeader(http.StatusBadRequest)
	enc := json.NewEncoder(w)
	if err := enc.Encode(&validationError); err != nil {
	log.Error("error encoding validation error", zap.Error(err))
	}
	return true
	}

api.go and apihandler.go and errorhandler.go and internalapihandler.go combined are over 3k LOC so there's a lot of ground to cover in terms of understanding how it comes together. I don't frequently use Golang so it's possible that I'm missing an obvious fix.

Anybody is welcome to make a PR for this if they can find the right way to set the header in the response for validation errors. Unfortunately I've exhausted the time I can spend on it for now.

[Pagebakers]

Fix: #1337