feat: add trailingSlash option

README.md

@@ -70,7 +70,7 @@ export default defineConfig({
 
 A server entry file is required. The file is should be placed at `app/server.ts`. This file is first called by the Vite during the development or build phase.
 
-In the entry file, simply initialize your app using the `createApp()` function. `app` will be an instance of Hono, so you can use Hono's middleware and the `showRoutes()`in`hono/dev`.
+In the entry file, simply initialize your app using the `createApp()` function. `app` will be an instance of Hono, so you can use Hono's middleware and the `showRoutes()` in `hono/dev`.
 
 ```ts
 // app/server.ts
@@ -545,6 +545,24 @@ export default createRoute(zValidator('form', schema), ...<more-middleware>)
 
 Note that is some scenarios, auto-complete for the request body within the route may be lost depending on how the middleware was written.
 
+### Trailing Slash
+
+By default, trailing slashes are removed if the root file is an index file such as `index.tsx` or `index.mdx`.
+However, if you set the `trailingSlash` option to `true` as the following, the trailing slash is not removed.
+
+```ts
+import { createApp } from 'honox/server'
+
+const app = createApp({
+  trailingSlash: true,
+})
+```
+
+Like the followings:
+
+- `trailingSlash` is `false` (default): `app/routes/path/index.mdx` => `/path`
+- `trailingSlash` is `true`: `app/routes/path/index.mdx` => `/path/`
+
 ### Using Tailwind CSS
 
 Given that HonoX is Vite-centric, if you wish to utilize [Tailwind CSS](https://tailwindcss.com/), simply adhere to the official instructions.

src/server/server.ts

@@ -43,6 +43,11 @@ type BaseServerOptions<E extends Env = Env> = {
   root: string
   app?: Hono<E>
   init?: InitFunction<E>
+  /**
+   * Appends a trailing slash to URL if the route file is an index file, e.g., `index.tsx` or `index.mdx`.
+   * @default false
+   */
+  trailingSlash?: boolean
 }
 
 export type ServerOptions<E extends Env = Env> = Partial<BaseServerOptions<E>>
@@ -53,6 +58,7 @@ export const createApp = <E extends Env>(options: BaseServerOptions<E>): Hono<E>
   const root = options.root
   const rootRegExp = new RegExp(`^${root}`)
   const app = options.app ?? new Hono()
+  const trailingSlash = options.trailingSlash ?? false
 
   if (options.init) {
     options.init(app)
@@ -178,6 +184,11 @@ export const createApp = <E extends Env>(options: BaseServerOptions<E>): Hono<E>
       applyNotFound(subApp, dir, notFoundMap)
       // Error
       applyError(subApp, dir, errorMap)
+
+      if (trailingSlash) {
+        rootPath = /\/$/.test(rootPath) ? rootPath : rootPath + '/'
+      }
+
       app.route(rootPath, subApp)
     }
   }

src/server/with-defaults.ts

@@ -7,6 +7,7 @@ export const createApp = <E extends Env>(options?: ServerOptions<E>) => {
     root: options?.root ?? '/app/routes',
     app: options?.app,
     init: options?.init,
+    trailingSlash: options?.trailingSlash,
     NOT_FOUND:
       options?.NOT_FOUND ??
       import.meta.glob('/app/routes/**/_404.(ts|tsx)', {

test/hono-jsx/app-nested/routes/top.tsx

@@ -0,0 +1,3 @@
+export default function Top() {
+  return <h1>Top</h1>
+}

test/hono-jsx/integration.test.ts

@@ -579,3 +579,36 @@ describe('Island Components with Preserved Files', () => {
     )
   })
 })
+
+describe('Trailing Slash', () => {
+  const ROUTES = import.meta.glob('./app-nested/routes/**/[a-z[-][a-z-_[]*.(tsx|ts)', {
+    eager: true,
+  })
+
+  const app = createApp({
+    root: './app-nested/routes',
+    ROUTES: ROUTES as any,
+    trailingSlash: true,
+  })
+
+  const paths = ['/nested', '/nested/foo', '/nested/foo/bar', '/nested/foo/bar/baz']
+  for (const path of paths) {
+    it(`Should return 404 response - ${path}`, async () => {
+      const res = await app.request(path)
+      expect(res.status).toBe(404)
+    })
+    it(`Should return 200 response - ${path}/`, async () => {
+      const res = await app.request(`${path}/`)
+      expect(res.status).toBe(200)
+    })
+  }
+
+  it('Should return 200 response - /top', async () => {
+    const res = await app.request('/top')
+    expect(res.status).toBe(200)
+  })
+  it('Should return 404 response - /top/', async () => {
+    const res = await app.request('/top/')
+    expect(res.status).toBe(404)
+  })
+})