Avoid dev TrackerHub poll gateway timeouts

src/shared/signalr/connection.ts

@@ -224,6 +224,8 @@ export function _resetSharedConnections(): void {
 
 // ---- Default builder (dynamic import) ----
 
+const DEV_TRACKER_LONG_POLL_TIMEOUT_MS = 10000;
+
 export function _shouldUseLongPollingForDevTrackerProxy(url: string): boolean {
   try {
     const parsed = new URL(url, "http://localhost");
@@ -241,15 +243,39 @@ async function defaultBuildConnection(
   url: string,
   delays: number[],
 ): Promise<HubConnectionLike> {
-  const { HubConnectionBuilder, HttpTransportType, LogLevel } = await import(
-    "@microsoft/signalr"
-  );
+  const {
+    DefaultHttpClient,
+    HttpClient,
+    HubConnectionBuilder,
+    HttpTransportType,
+    LogLevel,
+    NullLogger,
+  } = await import("@microsoft/signalr");
   const builder = new HubConnectionBuilder();
-  const withUrlOptions = _shouldUseLongPollingForDevTrackerProxy(url)
-    ? { transport: HttpTransportType.LongPolling }
+  const useDevTrackerLongPolling = _shouldUseLongPollingForDevTrackerProxy(url);
+  const withUrlOptions = useDevTrackerLongPolling
+    ? {
+        transport: HttpTransportType.LongPolling,
+        httpClient: new (class extends HttpClient {
+          private readonly inner = new DefaultHttpClient(NullLogger.instance);
+
+          send(request: Parameters<InstanceType<typeof HttpClient>["send"]>[0]) {
+            if (request.method !== "GET") {
+              return this.inner.send(request);
+            }
+
+            return this.inner.send({
+              ...request,
+              timeout: DEV_TRACKER_LONG_POLL_TIMEOUT_MS,
+            });
+          }
+        })(),
+      }
     : undefined;
 
-  return (withUrlOptions ? builder.withUrl(url, withUrlOptions) : builder.withUrl(url))
+  return (withUrlOptions
+    ? builder.withUrl(url, withUrlOptions)
+    : builder.withUrl(url))
     .withAutomaticReconnect(delays)
     // Suppress SignalR's internal console logging. The hub is optional
     // (failures degrade to polling) and we already handle status via