$refs inside additionalProperties are not converted from definitions to components/schema

[jldmn]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Fastify version

5.0.0

Plugin version

9.0.0

Node.js version

20.17.0

Operating system

Windows

Operating system version (i.e. 20.04, 11.3, 10)

22H2

Description

When using $ref inside patternProperties the relative path is not adjusted to reference components/schema instead of definitions, thus resulting in a broken reference.

So this basic example:

server
  .addSchema({
    $id: 'FileVariant',
    title: 'FileVariant',
    type: 'object',
    properties: {
     ...
    }
  })
  .addSchema({
    $id: 'File',
    title: 'File',
    type: 'object',
    properties: {
      variants: {
        type: 'object',
        patternProperties: {
          '^[A-z0-9-]{1,50}$': {
            $ref: 'FileVariant#'
          }
        }
      }
    }
  })

results in this broken spec:

{
  "openapi": "3.0.0",
  "components": {
    "schemas": {
      "def-0": {
        "title": "FileVariant",
        "description": "",
        "type": "object",
        "properties": {
         
        },
        "additionalProperties": false
      },
      "def-1": {
        "title": "File",
        "type": "object",
        "properties": {
          "variants": {
            "type": "object",
            "additionalProperties": {
              "$ref": "#/definitions/def-0"
            }
          }
        },
        "required": [],
        "additionalProperties": false
      }
    }
  }
}

instead of the correct:

"additionalProperties": {
  "$ref": "#/components/schmemas/def-0"
}

Link to code that reproduces the bug

No response

Expected Behavior

The expected behavior would be to correctly reference other schemas trough $ref inside the patterProperties as described in the upper example.