fix(dev-server): Fix issue in dev-server where requestListener would return null (#212)

* Fix issue in dev-server where requestListener would return null

* add patch changeset for dev-server fix

* add a test

---------

Co-authored-by: Yusuke Wada <yusuke@kamawada.com>

Author: gobengo

.changeset/long-panthers-decide.md

@@ -0,0 +1,5 @@
+---
+'@hono/vite-dev-server': patch
+---
+
+dev-server plugin getRequestListener fetchCallback now always returns Promise<Response> instead of sometimes returning Promise<null>

packages/dev-server/e2e/e2e.test.ts

@@ -1,4 +1,4 @@
-import { test, expect } from '@playwright/test'
+import { test, expect, request } from '@playwright/test'
 
 test('Should return 200 response', async ({ page }) => {
   const response = await page.goto('/')
@@ -122,3 +122,16 @@ test('Should return files in the public directory', async ({ page }) => {
   const res = await page.goto('/hono-logo.png')
   expect(res?.status()).toBe(200)
 })
+
+test('Should not crash when receiving a HEAD request', async () => {
+  const apiContext = await request.newContext()
+  const response = await apiContext.fetch('/', {
+    method: 'HEAD',
+  })
+
+  expect(response.status()).toBe(200)
+  expect(response.headers()['content-type']).toMatch(/^text\/html/)
+  const body = await response.body()
+  expect(body.length).toBe(0)
+  await apiContext.dispose()
+})

packages/dev-server/src/dev-server.ts

@@ -126,7 +126,7 @@ export function devServer(options?: DevServerOptions): VitePlugin {
           }
 
           getRequestListener(
-            async (request) => {
+            async (request): Promise<Response> => {
               let env: Env = {}
 
               if (options?.env) {
@@ -168,7 +168,7 @@ export function devServer(options?: DevServerOptions): VitePlugin {
                   .get('content-security-policy')
                   ?.match(/'nonce-([^']+)'/)?.[1]
                 const script = `<script${nonce ? ` nonce="${nonce}"` : ''}>import("/@vite/client")</script>`
-                return injectStringToResponse(response, script)
+                return injectStringToResponse(response, script) ?? response
               }
               return response
             },