fix: bun.serve crash due to ExceptionRef (#9309)

* fix bun.serve crash due to ExceptionRef

* add test

docs/guides/websocket/upgrade.md

@@ -1,28 +0,0 @@
----
-name: Upgrade an HTTP request to a WebSocket connection
----
-
-Inside `fetch`, use the `server.upgrade()` function to upgrade an incoming `Request` to a WebSocket connection. Bun automatically returns a 101 Switching Protocols response if the upgrade succeeds.
-
-Refer to the [WebSocket docs](/docs/api/websockets) for more information on building WebSocket servers.
-
-```ts
-const server = Bun.serve<{ authToken: string }>({
-  fetch(req, server) {
-    const success = server.upgrade(req);
-    if (success) {
-      // Bun automatically returns a 101 Switching Protocols
-      // if the upgrade succeeds
-      return undefined;
-    }
-
-    // handle HTTP request normally
-    return new Response("Hello world!");
-  },
-  websocket: {
-    // define websocket handlers
-  },
-});
-
-console.log(`Listening on localhost:\${server.port}`);
-```

src/bun.js/api/BunObject.zig

@@ -3022,6 +3022,10 @@ pub fn serve(
             return .undefined;
         }
 
+        if (globalObject.hasException()) {
+            return .zero;
+        }
+
         break :brk config_;
     };
 

test/js/bun/http/bun-server.test.ts

@@ -432,3 +432,49 @@ test("Bun.serve().unref() works", async () => {
 test("unref keeps process alive for ongoing connections", async () => {
   expect([path.join(import.meta.dir, "unref-fixture-2.ts")]).toRun();
 });
+
+test("Bun does not crash when given invalid config", async () => {
+  const server1 = Bun.serve({
+    fetch(request, server) {
+      //
+      throw new Error("Should not be called");
+    },
+    port: 0,
+  });
+
+  const cases = [
+    {
+      fetch() {},
+      port: server1.port,
+      websocket: {},
+    },
+    {
+      port: server1.port,
+      get websocket() {
+        throw new Error();
+      },
+    },
+    {
+      fetch() {},
+      port: server1.port,
+      get websocket() {
+        throw new Error();
+      },
+    },
+    {
+      fetch() {},
+      port: server1.port,
+      get ssl() {
+        throw new Error();
+      },
+    },
+  ];
+
+  for (const options of cases) {
+    expect(() => {
+      Bun.serve(options as any);
+    }).toThrow();
+  }
+
+  server1.stop();
+});