From 1160af8869221f2fced00778fb31b79da1a6b6bc Mon Sep 17 00:00:00 2001
From: Alexander Galabov <galabovalexandar@gmail.com>
Date: Fri, 6 Dec 2024 13:36:21 +0200
Subject: [PATCH] handle ref objects for responses

---
 spec/custom-components.spec.ts | 46 ++++++++++++++++++++++++++++++++++
 src/openapi-generator.ts       | 20 +++++++++++----
 src/openapi-registry.ts        |  2 +-
 3 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/spec/custom-components.spec.ts b/spec/custom-components.spec.ts
index cd258cf..23a8355 100644
--- a/spec/custom-components.spec.ts
+++ b/spec/custom-components.spec.ts
@@ -93,4 +93,50 @@ describe('Custom components', () => {
       },
     });
   });
+
+  it('can generate responses', () => {
+    const registry = new OpenAPIRegistry();
+
+    const response = registry.registerComponent('responses', 'BadRequest', {
+      description: 'BadRequest',
+      content: {
+        'application/json': {
+          schema: {
+            type: 'object',
+            properties: { name: { type: 'string' } },
+          },
+        },
+      },
+    });
+
+    registry.registerPath({
+      summary: 'Get user of an organization',
+      method: 'get',
+      path: '/test',
+      responses: {
+        '400': response.ref,
+      },
+    });
+
+    const builder = new OpenApiGeneratorV3(registry.definitions);
+    const document = builder.generateDocument(testDocConfig);
+
+    expect(document.paths['/test']?.get?.responses['400']).toEqual({
+      $ref: '#/components/responses/BadRequest',
+    });
+
+    expect(document.components!.responses).toEqual({
+      BadRequest: {
+        description: 'BadRequest',
+        content: {
+          'application/json': {
+            schema: {
+              type: 'object',
+              properties: { name: { type: 'string' } },
+            },
+          },
+        },
+      },
+    });
+  });
 });
diff --git a/src/openapi-generator.ts b/src/openapi-generator.ts
index 66d29d9..596f0c6 100644
--- a/src/openapi-generator.ts
+++ b/src/openapi-generator.ts
@@ -597,11 +597,15 @@ export class OpenAPIGenerator {
     return routeDoc;
   }
 
-  private getResponse({
-    content,
-    headers,
-    ...rest
-  }: ResponseConfig): ResponseObject | ReferenceObject {
+  private getResponse(
+    response: ResponseConfig | ReferenceObject
+  ): ResponseObject | ReferenceObject {
+    if (this.isReferenceObject(response)) {
+      return response;
+    }
+
+    const { content, headers, ...rest } = response;
+
     const responseContent = content
       ? { content: this.getBodyContent(content) }
       : {};
@@ -626,6 +630,12 @@ export class OpenAPIGenerator {
     };
   }
 
+  private isReferenceObject<T extends object>(
+    schema: T | ReferenceObject
+  ): schema is ReferenceObject {
+    return '$ref' in schema;
+  }
+
   private getResponseHeaders(headers: AnyZodObject): HeadersObject {
     const schemaShape = headers._def.shape();
 
diff --git a/src/openapi-registry.ts b/src/openapi-registry.ts
index f92dcb4..5b4df1a 100644
--- a/src/openapi-registry.ts
+++ b/src/openapi-registry.ts
@@ -119,7 +119,7 @@ export type RouteConfig = Omit<OperationObject, 'responses'> & {
     headers?: RouteParameter | ZodType<unknown>[];
   };
   responses: {
-    [statusCode: string]: ResponseConfig;
+    [statusCode: string]: ResponseConfig | ReferenceObject;
   };
 };