$ref in allOf in query/headers causes Fastify to crash

[HiiiiD]

Prerequisites

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

Fastify version

3.29.0

Plugin version

6.1.0

Node.js version

16.13.0

Operating system

Windows

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

10 Build 19044.1706

Description

allOf keyword put in query or headers schema causes Fastify to crash with this error

/app/node_modules/@fastify/swagger/lib/util/common.js:187
  return resolveLocalRef(externalSchemas[localRef], externalSchemas)
                                        ^

TypeError: Cannot read properties of undefined (reading 'schemas')
    at resolveLocalRef (/app/node_modules/@fastify/swagger/lib/util/common.js:187:41)
    at /app/node_modules/@fastify/swagger/lib/util/common.js:180:20
    at Array.reduce (<anonymous>)
    at resolveLocalRef (/app/node_modules/@fastify/swagger/lib/util/common.js:179:20)
    at plainJsonObjectToOpenapi3 (/app/node_modules/@fastify/swagger/lib/spec/openapi/utils.js:133:41)
    at resolveCommonParams (/app/node_modules/@fastify/swagger/lib/spec/openapi/utils.js:237:15)
    at prepareOpenapiMethod (/app/node_modules/@fastify/swagger/lib/spec/openapi/utils.js:339:29)
    at Object.swagger (/app/node_modules/@fastify/swagger/lib/spec/openapi/index.js:46:29)
    at prepare (/app/index.js:44:13)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)

Steps to Reproduce

const fastify = require('fastify')()

await fastify.register(require('@fastify/swagger'), {
    exposeRoute: true,
    routePrefix: '/docs',
    openapi: {
        info: { title: `Test OpenAPI`, version: '1.0.0' }
    }
})

fastify.addSchema({
    $id: 'test',
    type: 'object',
    properties: {
        field1: { type: 'integer' }
    }
})

fastify.put('/test-route', {
  schema: {
    query: {
        allOf: [{
            $ref: 'test'
        }, {
            type: 'object',
            properties: {
                field2: { type: 'string' }
            }
        }]
    },
    response: {
      200: {
          type: 'object',
          properties: {
              result: { type: 'string' }
          }
      }
    }
  }
}, (req, reply) => ({ result: 'OK' }))

await fastify.ready()
fastify.swagger()

Expected Behavior

No error should occur.

[mcollina]

Would you like to send a Pull Request to address this issue? Remember to add unit tests.

[HiiiiD]

Of course. I'll create it asap

[HiiiiD]

@mcollina Should I create the pull-request even though the CI is currently failing?