fix: file content-type

package.json

@@ -2,9 +2,9 @@
   "name": "img-mom",
   "version": "0.1.0",
   "private": true,
-	"engines": {
-		"node": ">=20.0.0"
-	},
+  "engines": {
+    "node": ">=20.0.0"
+  },
   "scripts": {
     "dev": "wrangler dev src/index.ts",
     "tunnel": "cloudflared tunnel --url http://127.0.0.1:8787",
@@ -18,6 +18,7 @@
   },
   "dependencies": {
     "@aws-sdk/client-s3": "^3.627.0",
+    "file-type": "^19.5.0",
     "grammy": "^1.28.0",
     "hono": "^4.5.4"
   }

src/index.ts

@@ -1,6 +1,7 @@
 import { Hono } from 'hono';
 import { webhookCallback } from 'grammy/web';
 import bot from './bot';
+import { fileTypeFromBuffer } from 'file-type'
 
 const app = new Hono();
 
@@ -37,10 +38,12 @@ app.get('/img/:fileId', async (ctx) => {
   	return ctx.text('404 Not Found. Please visit ImgMom docs (https://github.com/beilunyang/img-mom)', 404);
 	}
 
-	const fileType = file.file_path?.split('.').pop() ?? '';
+	const bf = await res.arrayBuffer()
 
-	return ctx.body(await res.arrayBuffer(), 200, {
-		'Content-Type': `image/${fileType}`
+	const fileType = await fileTypeFromBuffer(bf)
+
+	return ctx.body(bf, 200, {
+		'Content-Type': fileType?.mime ?? '',
 	});
 });