test(vite): send sec-fetch-dest: script for client module fetch

The HMR test fetches /app/entry-client.ts without sec-fetch-dest,
causing the Nitro dev middleware to route it through SSR instead
of letting Vite serve the transformed module.

Author: pi0

test/vite/hmr.test.ts

@@ -70,7 +70,9 @@ describe("vite:hmr", { sequential: true }, () => {
 
   test("Editing client entry (no full-reload)", async () => {
     files.client.update((content) => content.replace(`+ ""`, `+ " (modified)"`));
-    await pollResponse(`${serverURL}/app/entry-client.ts`, /modified/);
+    await pollResponse(`${serverURL}/app/entry-client.ts`, /modified/, 5000, {
+      "sec-fetch-dest": "script",
+    });
     expect(wsMessages.length).toBe(0);
   });
 
@@ -128,14 +130,15 @@ function waitFor(check: () => boolean, duration: number): Promise<void> {
 function pollResponse(
   url: string,
   match: RegExp | ((txt: string) => boolean),
-  timeout = 5000
+  timeout = 5000,
+  headers?: Record<string, string>
 ): Promise<string> {
   const start = Date.now();
   let lastResponse = "";
   return new Promise((resolve, reject) => {
     const check = async () => {
       try {
-        const response = await fetch(url);
+        const response = await fetch(url, headers ? { headers } : undefined);
         lastResponse = await response.text();
         if (typeof match === "function" ? match(lastResponse) : match.test(lastResponse)) {
           resolve(lastResponse);