Schema that worked in v4 no longer works in v5

[smonn]

Prerequisites

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

Fastify version

4.2.0

Plugin version

5.0.3

Node.js version

16.15.1

Operating system

macOS

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

12.4

Description

I encountered this error after upgrading to Fastify v4.2.0 which included v5 of fast-json-stringify. This error is thrown:

Error: no schema with key or ref "schema#/properties/union/anyOf/0"
    at Ajv.validate (.../node_modules/ajv/lib/core.ts:359:21)
    at anonymous0 (eval at build (.../node_modules/fast-json-stringify/index.js:177:23), <anonymous>:45:20)
    at main (eval at build (.../node_modules/fast-json-stringify/index.js:177:23), <anonymous>:6:15)
    at Object.<anonymous> (.../src/index.ts:80:5)
    at Module._compile (node:internal/modules/cjs/loader:1105:14)
    at Module.m._compile (.../node_modules/ts-node/src/index.ts:1597:23)
    at Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
    at Object.require.extensions.<computed> [as .ts] (.../node_modules/ts-node/src/index.ts:1600:12)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)

For reference, I also reported an issue over in the TypeBox repo: sinclairzx81/typebox#184

Steps to Reproduce

Use the following schema to validate { name: 'foo', union: 'a8f1cc50-5530-5c62-9109-5ba9589a6ae1' } and you should see the error. In v4 there is no error and it stringifies things correctly.

{
  "$id": "schema",
  "type": "object",
  "allOf": [
    {
      "$id": "base",
      "type": "object",
      "properties": {
        "name": {
          "type": "string"
        }
      },
      "required": [
        "name"
      ]
    },
    {
      "$id": "inner_schema",
      "type": "object",
      "properties": {
        "union": {
          "$id": "id",
          "anyOf": [
            {
              "format": "uuid",
              "$id": "guid",
              "type": "string"
            },
            {
              "format": "email",
              "$id": "email",
              "type": "string"
            }
          ]
        }
      },
      "required": [
        "union"
      ]
    }
  ]
}

Expected Behavior

It should work the same as before using v4 of fast-json-stringify.