Handle dev TrackerHub poll timeouts in proxy

scripts/dev-server.mjs

@@ -10,7 +10,7 @@
  *   /*          → localhost:8081 (Modern.js SSR + HMR)
  */
 import express from "express";
-import { createProxyMiddleware } from "http-proxy-middleware";
+import { createProxyMiddleware, responseInterceptor } from "http-proxy-middleware";
 import { HttpsProxyAgent } from "https-proxy-agent";
 import { execFile, spawn } from "node:child_process";
 import { resolve } from "node:path";
@@ -159,6 +159,25 @@ function normalizeTrackerCookie(cookie) {
   return [...parts, "Path=/tracker/hub", "SameSite=Lax"].join("; ");
 }
 
+function applyTrackerCookieHeaders(proxyRes, res) {
+  const setCookie = proxyRes.headers["set-cookie"];
+  if (Array.isArray(setCookie)) {
+    res.setHeader("set-cookie", setCookie.map(normalizeTrackerCookie));
+  } else if (typeof setCookie === "string") {
+    res.setHeader("set-cookie", normalizeTrackerCookie(setCookie));
+  }
+}
+
+function isTrackerLongPollTimeout(proxyRes, req) {
+  const requestUrl = req.originalUrl ?? req.url ?? "";
+  return (
+    req.method === "GET" &&
+    (requestUrl.startsWith("/tracker/hub?id=") ||
+      requestUrl.startsWith("/hub?id=")) &&
+    proxyRes.statusCode === 504
+  );
+}
+
 // --- SignalR TrackerHub proxy ---
 // Browser-direct localhost → platform.test.aeroflot.ru fails CORS. Keep the
 // hub same-origin in development and let proxy-helper / gost route the
@@ -170,15 +189,21 @@ const trackerProxy = createProxyMiddleware({
   ws: true,
   logLevel: "warn",
   pathRewrite: (path) => `/tracker${path}`,
+  selfHandleResponse: true,
   on: {
-    proxyRes(proxyRes) {
-      const setCookie = proxyRes.headers["set-cookie"];
-      if (Array.isArray(setCookie)) {
-        proxyRes.headers["set-cookie"] = setCookie.map(normalizeTrackerCookie);
-      } else if (typeof setCookie === "string") {
-        proxyRes.headers["set-cookie"] = normalizeTrackerCookie(setCookie);
+    proxyRes: responseInterceptor(async (buffer, proxyRes, req, res) => {
+      applyTrackerCookieHeaders(proxyRes, res);
+
+      if (isTrackerLongPollTimeout(proxyRes, req)) {
+        console.warn(`Tracker long poll timed out upstream, returning empty 200 for ${req.originalUrl ?? req.url}`);
+        res.statusCode = 200;
+        res.statusMessage = "OK";
+        res.setHeader("content-type", "text/plain");
+        return "";
       }
-    },
+
+      return buffer;
+    }),
   },
   ...(SYSTEM_PROXY ? { agent: new HttpsProxyAgent(SYSTEM_PROXY) } : {}),
 });