Fix: add not found response

src/app.service.ts

@@ -6,6 +6,8 @@ import {
   S3ClientConfig,
   GetObjectCommand,
   GetObjectCommandInput,
+  GetObjectCommandOutput,
+  NoSuchKey,
 } from '@aws-sdk/client-s3';
 
 @Injectable()
@@ -28,14 +30,22 @@ export class AppService {
     return 'OK';
   }
 
-  async getObject(getObjectConfig: GetObjectCommandInput): Promise<Readable> {
+  async getObject(getObjectConfig: GetObjectCommandInput): Promise<Readable | null> {
     const command = new GetObjectCommand(getObjectConfig);
-    const res = await this.s3Client.send(command);
+    let res: GetObjectCommandOutput;
+    try {
+      res = await this.s3Client.send(command);
+    } catch (err: unknown) {
+      if (err instanceof NoSuchKey)
+        return null;
+      throw err;
+    }
     if (!res.Body)
       throw new HttpException(
         's3 get object failed',
         HttpStatus.INTERNAL_SERVER_ERROR,
       );
+
     return res.Body as Readable;
   }
 }