fix: memory leak in entry.server (#14200)

Author: jacob-ebey

.changeset/rotten-parents-care.md

@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+fix: memory leak in default entry.server

packages/react-router-dev/config/defaults/entry.server.node.tsx

@@ -14,7 +14,7 @@ export default function handleRequest(
   responseStatusCode: number,
   responseHeaders: Headers,
   routerContext: EntryContext,
-  loadContext: AppLoadContext,
+  loadContext: AppLoadContext
   // If you have middleware enabled:
   // loadContext: unstable_RouterContextProvider
 ) {
@@ -29,24 +29,38 @@ export default function handleRequest(
         ? "onAllReady"
         : "onShellReady";
 
+    // Abort the rendering stream after the `streamTimeout` so it has time to
+    // flush down the rejected boundaries
+    let timeoutId: ReturnType<typeof setTimeout> | undefined = setTimeout(
+      () => abort(),
+      streamTimeout + 1000
+    );
+
     const { pipe, abort } = renderToPipeableStream(
       <ServerRouter context={routerContext} url={request.url} />,
       {
         [readyOption]() {
           shellRendered = true;
-          const body = new PassThrough();
+          const body = new PassThrough({
+            final(callback) {
+              // Clear the timeout to prevent retaining the closure and memory leak
+              clearTimeout(timeoutId);
+              timeoutId = undefined;
+              callback();
+            },
+          });
           const stream = createReadableStreamFromReadable(body);
 
           responseHeaders.set("Content-Type", "text/html");
 
+          pipe(body);
+
           resolve(
             new Response(stream, {
               headers: responseHeaders,
               status: responseStatusCode,
-            }),
+            })
           );
-
-          pipe(body);
         },
         onShellError(error: unknown) {
           reject(error);
@@ -60,11 +74,7 @@ export default function handleRequest(
             console.error(error);
           }
         },
-      },
+      }
     );
-
-    // Abort the rendering stream after the `streamTimeout` so it has time to
-    // flush down the rejected boundaries
-    setTimeout(abort, streamTimeout + 1000);
   });
 }