feat(zod-openapi): Make context accessible in the doc route (#272)

* feat(zod-openapi): Make context accessible in the doc route

* docs(zod-openapi): Fix typo

* docs(zod-openapi): Add a tips to the README.md on how to access the context in app.doc

.changeset/tough-eels-exist.md

@@ -0,0 +1,5 @@
+---
+'@hono/zod-openapi': minor
+---
+
+Make context accessible in the doc route

packages/zod-openapi/README.md

@@ -231,7 +231,7 @@ You can generate OpenAPI v3.1 spec using the following methods:
 
 ```ts
 app.doc31('/docs', {openapi: '3.1.0'}) // new endpoint
-app.getOpenAPI31Document(, {openapi: '3.1.0'}) // raw json
+app.getOpenAPI31Document({openapi: '3.1.0'}) // raw json
 ```
 
 ### The Registry
@@ -312,7 +312,7 @@ app.openAPIRegistry.registerComponent('securitySchema', {
     type: 'http',
     scheme: 'bearer',
   },
-}
+})
 ```
 
 And setup the security scheme for specific routes:
@@ -328,6 +328,26 @@ const route = createRoute({
 })
 ```
 
+### How to access context in app.doc
+
+You can access the context in `app.doc` as follows:
+
+```ts
+app.doc('/doc', c => ({
+  openapi: '3.0.0',
+  info: {
+    version: '1.0.0',
+    title: 'My API',
+  },
+  servers: [
+    {
+      url: new URL(c.req.url).hostname,
+      description: 'Current environment',
+    },
+  ],
+}))
+```
+
 ## Limitations
 
 ### Combining with `Hono`

packages/zod-openapi/src/index.ts

@@ -185,6 +185,10 @@ export type RouteHook<
   P extends string = ConvertPathType<R['path']>
 > = Hook<I, E, P, OutputType<R>>
 
+export type OpenAPIObjectConfigure<E extends Env, P extends string> =
+  OpenAPIObjectConfig |
+  ((context: Context<E, P>) => OpenAPIObjectConfig)
+
 export class OpenAPIHono<
   E extends Env = Env,
   S extends Schema = {},
@@ -279,9 +283,10 @@ export class OpenAPIHono<
 
   doc = <P extends string>(
     path: P,
-    config: OpenAPIObjectConfig
+    configure: OpenAPIObjectConfigure<E, P>
   ): OpenAPIHono<E, S & ToSchema<'get', P, {}, {}>, BasePath> => {
     return this.get(path, (c) => {
+      const config = typeof configure === 'function' ? configure(c) : configure
       const document = this.getOpenAPIDocument(config)
       return c.json(document)
     }) as any
@@ -289,9 +294,10 @@ export class OpenAPIHono<
 
   doc31 = <P extends string>(
     path: P,
-    config: OpenAPIObjectConfig
+    configure: OpenAPIObjectConfigure<E, P>
   ): OpenAPIHono<E, S & ToSchema<'get', P, {}, {}>, BasePath> => {
     return this.get(path, (c) => {
+      const config = typeof configure === 'function' ? configure(c) : configure
       const document = this.getOpenAPI31Document(config)
       return c.json(document)
     }) as any

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

@@ -1121,3 +1121,57 @@ describe('Path normalization', () => {
     })
   })
 })
+
+describe('Context can be accessible in the doc route', () => {
+  const app = new OpenAPIHono<{ Bindings: { TITLE: string } }>()
+
+  app.openapi(
+    createRoute({
+      method: 'get',
+      path: '/no-content',
+      responses: {
+        204: {
+          description: 'No Content',
+        },
+      },
+    }),
+    (c) => {
+      return c.body(null, 204)
+    }
+  )
+
+  app.doc('/doc', context => ({
+    openapi: '3.0.0',
+    info: {
+      version: '1.0.0',
+      title: context.env.TITLE,
+    },
+  }))
+
+  it('Should return with the title set as specified in env', async () => {
+    const res = await app.request('/doc', null, { TITLE: 'My API' })
+    expect(res.status).toBe(200)
+    expect(await res.json()).toEqual({
+      openapi: '3.0.0',
+      info: {
+        version: '1.0.0',
+        title: 'My API',
+      },
+      components: {
+        schemas: {},
+        parameters: {},
+      },
+      paths: {
+        '/no-content': {
+          get: {
+            responses: {
+              204: {
+                description: 'No Content',
+              },
+            },
+          },
+        },
+      },
+    })
+  })
+})