feat(zod-openapi): Add 'middleware' property for route (#435)

* feat: Add 'middlewares' property for route

* fix: Rename `middlewares` to `middleware`

* fix: Update README.md

* fix: Fix changeset

.changeset/gentle-plums-worry.md

@@ -0,0 +1,5 @@
+---
+'@hono/zod-openapi': minor
+---
+
+Add 'middleware' property for route

packages/zod-openapi/README.md

@@ -270,6 +270,32 @@ app.use(route.getRoutingPath(), prettyJSON(), cache({ cacheName: 'my-cache' }))
 app.openapi(route, handler)
 ```
 
+Or you can use the `middleware` property in the route definition.
+
+```ts
+const route = createRoute({
+  method: 'get',
+  path: '/users/{id}',
+  request: {
+    params: ParamsSchema,
+  },
+  middleware: [
+    prettyJSON(),
+    cache({ cacheName: 'my-cache' })
+  ],
+  responses: {
+    200: {
+      content: {
+        'application/json': {
+          schema: UserSchema,
+        },
+      },
+      description: 'Retrieve the user',
+    },
+  },
+})
+```
+
 ### RPC Mode
 
 Zod OpenAPI Hono supports Hono's RPC mode. You can define types for the Hono Client as follows:

packages/zod-openapi/src/index.ts

@@ -2,7 +2,7 @@
 /* eslint-disable @typescript-eslint/no-unused-vars */
 import type {
   ResponseConfig,
-  RouteConfig,
+  RouteConfig as RouteConfigBase,
   ZodContentObject,
   ZodMediaTypeObject,
   ZodRequestBody,
@@ -32,6 +32,10 @@ import { mergePath } from 'hono/utils/url'
 import type { AnyZodObject, ZodSchema, ZodError } from 'zod'
 import { z, ZodType } from 'zod'
 
+type RouteConfig = RouteConfigBase & {
+  middleware?: MiddlewareHandler | MiddlewareHandler[]
+}
+
 type RequestTypes = {
   body?: ZodRequestBody
   params?: AnyZodObject
@@ -310,7 +314,9 @@ export class OpenAPIHono<
       }
     }
 
-    this.on([route.method], route.path.replaceAll(/\/{(.+?)}/g, '/:$1'), ...validators, handler)
+    const middleware = route.middleware ? (Array.isArray(route.middleware) ? route.middleware : [route.middleware]) : []
+
+    this.on([route.method], route.path.replaceAll(/\/{(.+?)}/g, '/:$1'), ...middleware, ...validators, handler)
     return this
   }
 

packages/zod-openapi/test/index.test.ts

@@ -1361,3 +1361,29 @@ describe('Handle "Conflicting names for parameter"', () => {
     })
   })
 })
+
+describe('Middleware', () => {
+  const app = new OpenAPIHono()
+  app.openapi(
+    createRoute({
+      method: 'get',
+      path: '/books',
+      middleware: [(c, next) => {
+        c.header('x-foo', 'bar')
+        return next()
+      }],
+      responses: {
+        200: {
+          description: 'response',
+        },
+      },
+    }),
+    (c) => c.text('foo')
+  )
+
+  it('Should have the header set by the middleware', async () => {
+    const res = await app.request('/books')
+    expect(res.status).toBe(200)
+    expect(res.headers.get('x-foo')).toBe('bar')
+  })
+})