fix: destroy sockets to stop memory leaking when stream errors (#2336)

src/file.ts

@@ -1433,6 +1433,7 @@ class File extends ServiceObject<File, FileMetadata> {
     const tailRequest = options.end! < 0;
 
     let validateStream: HashStreamValidator | undefined = undefined;
+    let request: r.Request | undefined = undefined;
 
     const throughStream = new PassThroughShim();
 
@@ -1464,6 +1465,11 @@ class File extends ServiceObject<File, FileMetadata> {
 
     const onComplete = (err: Error | null) => {
       if (err) {
+        // There is an issue with node-fetch 2.x that if the stream errors the underlying socket connection is not closed.
+        // This causes a memory leak, so cleanup the sockets manually here by destroying the agent.
+        if (request?.agent) {
+          request.agent.destroy();
+        }
         throughStream.destroy(err);
       }
     };
@@ -1492,6 +1498,7 @@ class File extends ServiceObject<File, FileMetadata> {
         return;
       }
 
+      request = (rawResponseStream as r.Response).request;
       const headers = (rawResponseStream as ResponseBody).toJSON().headers;
       const isCompressed = headers['content-encoding'] === 'gzip';
       const hashes: {crc32c?: string; md5?: string} = {};