express-openapi: Allow reference in schema property of response object

express-openapi/express-openapi-tests.ts

@@ -40,6 +40,10 @@ get.apiDoc = {
         }
     ],
     responses: {
+        200: {
+            description: "valid user object",
+            schema: {$ref: '#/definitions/user'}
+        },
         default: {$ref: '#/definitions/error'}
     },
     "x-some-vendor-property": {}

express-openapi/express-openapi.d.ts

@@ -128,7 +128,7 @@ declare module "express-openapi" {
 
         export interface ResponseObject {
             description: string
-            schema?: SchemaObject
+            schema?: Schema
             headers?: HeadersObject
             examples?: ExampleObject
         }
@@ -209,7 +209,7 @@ declare module "express-openapi" {
         }
 
         export interface InBodyParameterObject extends ParameterObject {
-            schema: SchemaObject
+            schema: Schema
         }
 
         export interface GeneralParameterObject extends ParameterObject, ItemsObject {
@@ -226,6 +226,8 @@ declare module "express-openapi" {
             url: string
         }
 
+        type Schema = SchemaObject | ReferenceObject
+
         export interface SchemaObject extends IJsonSchema {
             [index: string]: any
             discriminator?: string