fix: add response object for ping

Signed-off-by: Raymond Feng <[email protected]>

src/controllers/ping.controller.ts

@@ -7,14 +7,41 @@ import {Request, RestBindings} from '@loopback/rest';
 import {get} from '@loopback/openapi-v3';
 import {inject} from '@loopback/context';
 
+const PING_RESPONSE = {
+  description: 'Ping Response',
+  content: {
+    'application/json': {
+      schema: {
+        type: 'object',
+        properties: {
+          greeting: {type: 'string'},
+          date: {type: 'string'},
+          url: {type: 'string'},
+          headers: {
+            type: 'object',
+            patternProperties: {
+              '^.*$': {type: 'string'},
+            },
+            additionalProperties: false,
+          },
+        },
+      },
+    },
+  },
+};
+
 /**
  * A simple controller to bounce back http requests
  */
 export class PingController {
   constructor(@inject(RestBindings.Http.REQUEST) private req: Request) {}
 
   // Map to `GET /ping`
-  @get('/ping')
+  @get('/ping', {
+    responses: {
+      '200': PING_RESPONSE,
+    },
+  })
   ping(): object {
     return {
       greeting: 'Hello from LoopBack',