feat: add custom headers option to serve static

src/middleware/serve-static/index.test.ts

@@ -18,6 +18,9 @@ describe('Serve Static Middleware', () => {
     isDir: (path) => {
       return path === 'static/hello.world'
     },
+    headers: (c) => ({
+      'Cache-Control': c.req.path === '/static/hello.html' ? 'public, max-age=31536000' : undefined,
+    }),
   })
 
   app.get('/static/*', serveStatic)
@@ -30,6 +33,7 @@ describe('Serve Static Middleware', () => {
     const res = await app.request('/static/hello.html')
     expect(res.status).toBe(200)
     expect(res.headers.get('Content-Type')).toMatch(/^text\/html/)
+    expect(res.headers.get('Cache-Control')).toBe('public, max-age=31536000')
     expect(await res.text()).toBe('Hello in ./static/hello.html')
   })
 
@@ -52,6 +56,7 @@ describe('Serve Static Middleware', () => {
     expect(res.status).toBe(200)
     expect(res.headers.get('Content-Type')).toMatch(/^text\/html/)
     expect(await res.text()).toBe('Hello in ./static/hello.world/index.html')
+    expect(res.headers.get('Cache-Control')).toBe(null)
   })
 
   it('Should decode URI strings - /static/%E7%82%8E.txt', async () => {
@@ -65,6 +70,7 @@ describe('Serve Static Middleware', () => {
     expect(res.status).toBe(404)
     expect(await res.text()).toBe('404 Not Found')
     expect(getContent).toBeCalledTimes(1)
+    expect(res.headers.get('Cache-Control')).toBe(null)
   })
 
   it('Should not allow a directory traversal - /static/%2e%2e/static/hello.html', async () => {

src/middleware/serve-static/index.ts

@@ -12,6 +12,7 @@ export type ServeStaticOptions<E extends Env = Env> = {
   root?: string
   path?: string
   mimes?: Record<string, string>
+  headers?: (c: Context) => Record<string, string | undefined>
   rewriteRequestPath?: (path: string) => string
   onNotFound?: (path: string, c: Context<E>) => void | Promise<void>
 }
@@ -85,6 +86,15 @@ export const serveStatic = <E extends Env = Env>(
       }
     }
 
+    const headers = options.headers?.(c)
+    if (headers) {
+      for (const [key, value] of Object.entries(headers)) {
+        if (value) {
+          c.header(key, value)
+        }
+      }
+    }
+
     if (content instanceof Response) {
       return c.newResponse(content.body, content)
     }