Astro request.signal abort event not called for SSE

[mihaiandrei97]

Astro Info

Astro                    v5.1.1
Node                     v20.9.0
System                   macOS (arm64)
Package Manager          npm
Output                   server
Adapter                  @astrojs/node
Integrations             none

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

While trying to implement SSE with node adapter in Astro, it seems the abort event is not triggered on request.signal when the connection is closed.

export const clients = new Set() as Set<(message: string) => void>;

export const GET: APIRoute = ({ request }) => {
  const responseHeaders = {
    "Content-Type": "text/event-stream",
    "Cache-Control": "no-cache",
    Connection: "keep-alive",
  };

  const stream = new ReadableStream({
    start(controller) {
      const encoder = new TextEncoder();

      // Function to send messages to this client
      const send = (message: string) => {
        controller.enqueue(encoder.encode(`data: ${message}\n\n`));
      };

      // Add the send function to the set of clients
      clients.add(send);

      // Send an initial message
      send("Connected to SSE");

      request.signal.addEventListener("abort", () => {
        console.log("Client disconnected ");
        clients.delete(send);
        controller.close();
      });

    },
  });

  return new Response(stream, { headers: responseHeaders });
};

What's the expected result?

The following callback should be called when the client disconnects.

request.signal.addEventListener("abort", () => {
  console.log("Client disconnected ");
});

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-yi4swteg?file=src%2Fpages%2Fsse.ts

Participation

• I am willing to submit a pull request for this issue.

[ematipico]

Can tell us how to reproduce the issue and how this signal/SSE is supposed to work?