fastify#462 Allow nested $ref to resolve for OpenAPI

 implementation

lib/spec/openapi/index.js

@@ -23,7 +23,17 @@ module.exports = function (opts, cache, routes, Ref, done) {
     openapiObject.components.schemas = prepareOpenapiSchemas({
       ...openapiObject.components.schemas,
       ...(ref.definitions().definitions)
-    },ref)
+    }, ref)
+
+    // Swagger doesn't accept $id on /definitions schemas.
+    // The $ids are needed by Ref() to check the URI so we need
+    // to remove them at the end of the process
+    // definitions are added by resolve but they are replace by components.schemas
+    Object.values(openapiObject.components.schemas)
+      .forEach((_) => {
+        delete _.$id
+        delete _.definitions
+      })
 
     for (const route of routes) {
       const schema = defOpts.transform

test/spec/openapi/refs.js

@@ -53,11 +53,9 @@ test('support nested $ref schema', (t) => {
     t.equal(typeof openapiObject, 'object')
     t.match(Object.keys(openapiObject.components.schemas), ['def-0', 'def-1'])
 
-    // OrderItem ref is not prefixed by '#/components/schemas/'
+    // OrderItem ref must be prefixed by '#/components/schemas/'
     t.equal(openapiObject.components.schemas['def-1'].properties.products.items.$ref, '#/components/schemas/def-0')
 
-    // open api validation failed
-    // ENOENT: no such file or directory ${cwd}/OrderItem
     Swagger.validate(openapiObject)
       .then(function (api) {
         t.pass('valid swagger object')