Use dynamic references when resolving schemas

Author: Nelspike

lib/spec/openapi/utils.js

@@ -305,13 +305,19 @@ function resolveCommonParams (container, parameters, schema, ref, sharedSchemas,
 
 // Keys to references could be different than the name of the $ref,
 // for example `def-0`
-function findReference (definitions, id) {
-  const schemaKey = Object.keys(definitions).find(key => {
-    const schema = definitions[key]
-    return schema.$id === id
-  })
+function findReferenceDescription (rawSchema, ref) {
+  // FIXME: Resolve directly?
+  const resolvedReference = ref.resolve(rawSchema, { externalSchemas: [ref.definitions().definitions] })
+
+  // Ref has format `#/definitions/id`
+  const schemaId = resolvedReference?.$ref?.split('/')[2]
 
-  return definitions[schemaKey] ?? {}
+  if (schemaId === undefined) {
+    return undefined
+  }
+
+  const schema = resolvedReference.definitions[schemaId]
+  return schema?.description
 }
 
 // https://swagger.io/docs/specification/describing-responses/
@@ -324,7 +330,6 @@ function resolveResponse (fastifyResponseJson, produces, ref) {
   const responsesContainer = {}
 
   const statusCodes = Object.keys(fastifyResponseJson)
-  const definitions = ref.definitions().definitions
 
   statusCodes.forEach(statusCode => {
     const rawJsonSchema = fastifyResponseJson[statusCode]
@@ -338,12 +343,10 @@ function resolveResponse (fastifyResponseJson, produces, ref) {
       statusCode = statusCode.toUpperCase()
     }
 
-    const referenceJsonSchema = findReference(definitions, rawJsonSchema.$ref)
-
     const response = {
       description: resolved[xResponseDescription] ||
         rawJsonSchema.description ||
-        referenceJsonSchema.description ||
+        findReferenceDescription(rawJsonSchema, ref) ||
         'Default Response'
     }
 

test/spec/openapi/schema.js

@@ -391,7 +391,7 @@ test('response: description and x-response-description', async () => {
   test('retrieve the response description from its given $ref schema', async t => {
     // Given a /description endpoint that also has a |description| field in its response referenced schema
     const fastify = Fastify()
-    await fastify.addSchema({
+    fastify.addSchema({
       $id: 'my-ref',
       description,
       type: 'string'
@@ -402,7 +402,7 @@ test('response: description and x-response-description', async () => {
       schema: {
         response: {
           200: {
-            $ref: 'my-ref'
+            $ref: 'my-ref#'
           }
         }
       }