webchat: improve logging and static serving

src/webchat/server.test.ts

@@ -30,6 +30,11 @@ const fetchText = (url: string) =>
       .on("error", reject);
   });
 
+const fetchHeaders = (url: string) =>
+  new Promise<http.IncomingHttpHeaders>((resolve, reject) => {
+    http.get(url, (res) => resolve(res.headers)).on("error", reject);
+  });
+
 describe("webchat server (static only)", () => {
   test("serves index.html over loopback", { timeout: 8000 }, async () => {
     const port = await getFreePort();
@@ -41,4 +46,17 @@ describe("webchat server (static only)", () => {
       await stopWebChatServer();
     }
   });
+
+  test("serves bundled JS with module-friendly content type", async () => {
+    const port = await getFreePort();
+    await startWebChatServer(port);
+    try {
+      const headers = await fetchHeaders(
+        `http://127.0.0.1:${port}/webchat.bundle.js`,
+      );
+      expect(headers["content-type"]).toContain("application/javascript");
+    } finally {
+      await stopWebChatServer();
+    }
+  });
 });