set content-type when uploading image

app/lib/s3.server.ts

@@ -25,13 +25,15 @@ export const s3 = singleton("s3-client", () => {
 
 export const s3uploadFile = async (
   filename: string,
-  file: PutObjectRequest["Body"] | string | Buffer
+  file: PutObjectRequest["Body"] | string | Buffer,
+  contentType?: string
 ) => {
   await s3.send(
     new PutObjectCommand({
       Bucket: S3_BUCKET_NAME,
       Key: filename,
       Body: file,
+      ContentType: contentType,
     })
   )
 }

app/routes/api/save-avatar.ts

@@ -20,7 +20,7 @@ export const action: ActionFunction = async ({ request }) => {
     }
     const buffer = Buffer.concat(chunks)
     const filename = `${user.id}/${nanoid()}.jpg`
-    await s3uploadFile(filename, buffer)
+    await s3uploadFile(filename, buffer, "image/jpeg")
     return filename
   }
   const formData = await unstable_parseMultipartFormData(request, uploadHandler)