fix: don't crash the server when a streaming response is aborted

ryansolid · cursoragent · ryansolid · commit d1b2ed04b290 · 2026-08-02T22:31:47.000-07:00
The generated SSR handler piped render output straight into the
ReadableStream controller. Enqueueing after the client aborts (page
reload, navigation away) throws ERR_INVALID_STATE — and streamed
fragments write seconds after the shell, so a mid-stream abort took
down the whole Node process from writeTasks. Guard writes behind a
closed flag, absorb the close race in end(), and mark closure on
cancel().

Co-authored-by: Cursor &lt;cursoragent@cursor.com&gt;
diff --git a/.changeset/fix-ssr-stream-abort-crash.md b/.changeset/fix-ssr-stream-abort-crash.md
@@ -0,0 +1,5 @@
+---
+"vite-plugin-solid": patch
+---
+
+The generated SSR handler no longer crashes the server process when a client aborts a streaming response mid-flight. Enqueueing into a closed `ReadableStream` controller throws, and a streamed fragment can land seconds after the shell — an abort (page reload, navigation away) during that window took down the whole Node process with `ERR_INVALID_STATE`. Writes are now dropped once the stream closes or is cancelled.
diff --git a/src/ssr/index.ts b/src/ssr/index.ts
@@ -478,18 +478,19 @@ export function ssrServe(
       `    return new Response('<!DOCTYPE html>' + transform(result), { status, headers });`,
       `  }`,
       `  const encoder = new TextEncoder();`,
+      // Streamed fragments write long after the shell; enqueueing after the
+      // client aborts throws, which would crash the server. Drop late writes.
+      `  let closed = false;`,
       `  const stream = new ReadableStream({`,
       `    start(controller) {`,
-      `      controller.enqueue(encoder.encode('<!DOCTYPE html>'));`,
+      `      const enqueue = v => { if (!closed) try { controller.enqueue(encoder.encode(v)); } catch { closed = true; } };`,
+      `      enqueue('<!DOCTYPE html>');`,
       `      result.pipe({`,
-      `        write(chunk) {`,
-      `          controller.enqueue(encoder.encode(transform(chunk)));`,
-      `        },`,
-      `        end() {`,
-      `          controller.close();`,
-      `        },`,
+      `        write(chunk) { enqueue(transform(chunk)); },`,
+      `        end() { if (!closed) { closed = true; try { controller.close(); } catch {} } },`,
       `      });`,
       `    },`,
+      `    cancel() { closed = true; },`,
       `  });`,
       `  return new Response(stream, { status, headers });`,
       `}`,

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"vite-plugin-solid": patch
 +---
++
 +The generated SSR handler no longer crashes the server process when a client aborts a streaming response mid-flight. Enqueueing into a closed `ReadableStream` controller throws, and a streamed fragment can land seconds after the shell — an abort (page reload, navigation away) during that window took down the whole Node process with `ERR_INVALID_STATE`. Writes are now dropped once the stream closes or is cancelled.