Bundling with JSON components no longer works

[FollowTheProcess]

Issue

BundleBytesComposed no longer hoists JSON $ref targets into components/schemas. It looks like it's started from 0.33.1 onwards (I noticed test failures when doing a bump and dug into it)

Repro

Tiny openapi spec with a User schema, the Go code simply prints the bundled spec.

Try swapping $ref: "User.json" for $ref: "User.yaml" and you should see the yaml one get correctly hoisted into components, while the JSON one does not.

main.go

package main

import (
	"fmt"
	"os"

	"github.com/pb33f/libopenapi/bundler"
	"github.com/pb33f/libopenapi/datamodel"
)

func main() {
	specBytes, err := os.ReadFile("openapi.yaml")
	if err != nil {
		panic(err)
	}

	out, err := bundler.BundleBytesComposed(specBytes, &datamodel.DocumentConfiguration{
		AllowFileReferences: true,
		BasePath:            ".",
		SpecFilePath:        "openapi.yaml",
	}, &bundler.BundleCompositionConfig{
		StrictValidation: true,
	})
	if err != nil {
		panic(err)
	}

	fmt.Println(string(out))
}

openapi.yaml

openapi: 3.0.3
info:
  title: t
  version: '1'
paths:
  /x:
    get:
      responses:
        '200':
          description: ok
          content:
            application/json:
              schema:
                $ref: "User.json" # <- Swap this for User.yaml and magically components/schemas starts to work

User.json

{
  "type": "object",
  "properties": {
    "id": {
      "type": "string"
    }
  }
}

User.yaml

type: object
properties:
  id:
    type: string

Digging

I think it has something to do with this bit:

libopenapi/bundler/detect_type.go

Lines 165 to 167 in e15ee6d

	// Skip quoted keys - they should not be treated as OpenAPI keywords
	if keyNode.Style == yaml.SingleQuotedStyle || keyNode.Style == yaml.DoubleQuotedStyle {
	continue

My guess is that JSON keys (because they are obviously quoted) get parsed here as yaml.DoubleQuotedStyle and are therefore skipped?