Fix Fetch + Cookies when using Node 18+ (#48076)

src/SignalR/clients/ts/signalr/src/FetchHttpClient.ts

@@ -20,14 +20,22 @@ export class FetchHttpClient extends HttpClient {
         super();
         this._logger = logger;
 
-        if (typeof fetch === "undefined") {
+        // Node added a fetch implementation to the global scope starting in v18.
+        // We need to add a cookie jar in node to be able to share cookies with WebSocket
+        if (typeof fetch === "undefined" || Platform.isNode) {
             // In order to ignore the dynamic require in webpack builds we need to do this magic
             // @ts-ignore: TS doesn't know about these names
             const requireFunc = typeof __webpack_require__ === "function" ? __non_webpack_require__ : require;
 
             // Cookies aren't automatically handled in Node so we need to add a CookieJar to preserve cookies across requests
             this._jar = new (requireFunc("tough-cookie")).CookieJar();
-            this._fetchType = requireFunc("node-fetch");
+
+            if (typeof fetch === "undefined") {
+                this._fetchType = requireFunc("node-fetch");
+            } else {
+                // Use fetch from Node if available
+                this._fetchType = fetch;
+            }
 
             // node-fetch doesn't have a nice API for getting and setting cookies
             // fetch-cookie will wrap a fetch implementation with a default CookieJar or a provided one