fix(jupyter): keep running event loop when waiting for messages (#26049)

Closes https://github.com/denoland/deno/issues/24421

cli/tools/jupyter/mod.rs

@@ -357,10 +357,31 @@ pub struct JupyterReplSession {
 
 impl JupyterReplSession {
   pub async fn start(&mut self) {
+    let mut poll_worker = true;
     loop {
-      let Some(msg) = self.rx.recv().await else {
+      tokio::select! {
+        biased;
+
+        maybe_message = self.rx.recv() => {
+          let Some(msg) = maybe_message else {
             break;
           };
+          if self.handle_message(msg).await.is_err() {
+            break;
+          }
+          poll_worker = true;
+        },
+        _ = self.repl_session.run_event_loop(), if poll_worker => {
+          poll_worker = false;
+        }
+      }
+    }
+  }
+
+  async fn handle_message(
+    &mut self,
+    msg: JupyterReplRequest,
+  ) -> Result<(), AnyError> {
     let resp = match msg {
       JupyterReplRequest::LspCompletions {
         line_text,
@@ -401,10 +422,7 @@ impl JupyterReplSession {
       }
     };
 
-      let Ok(()) = self.tx.send(resp) else {
+    self.tx.send(resp).map_err(|e| e.into())
-        break;
-      };
-    }
   }
 
   pub async fn lsp_completions(

tests/integration/jupyter_tests.rs

@@ -628,3 +628,37 @@ async fn jupyter_store_history_false() -> Result<()> {
 
   Ok(())
 }
+
+#[tokio::test]
+async fn jupyter_http_server() -> Result<()> {
+  let (_ctx, client, _process) = setup().await;
+  client
+    .send(
+      Shell,
+      "execute_request",
+      json!({
+        "silent": false,
+        "store_history": false,
+        "code": r#"Deno.serve({ port: 10234 }, (req) => Response.json({ hello: "world" }))"#,
+      }),
+    )
+    .await?;
+
+  let reply = client.recv(Shell).await?;
+  assert_eq!(reply.header.msg_type, "execute_reply");
+  assert_json_subset(
+    reply.content,
+    json!({
+      "status": "ok",
+      "execution_count": 0,
+    }),
+  );
+
+  for _ in 0..3 {
+    let resp = reqwest::get("http://localhost:10234").await.unwrap();
+    let text: serde_json::Value = resp.json().await.unwrap();
+    assert_eq!(text, json!({ "hello": "world" }));
+  }
+
+  Ok(())
+}