From 45112a30d1af4cc25b21a5d658a748583cb64ed4 Mon Sep 17 00:00:00 2001
From: Damien Arrachequesne <damien.arrachequesne@gmail.com>
Date: Tue, 18 Jan 2022 17:03:03 +0100
Subject: [PATCH] fix(uws): fix HTTP long-polling with CORS

When binding to an uWebSockets.js application, the server could crash
with the following error:

```
TypeError: res.onData is not a function
    at Polling.onDataRequest (build/transports-uws/polling.js:133:13)
    at Polling.onRequest (build/transports-uws/polling.js:47:18)
    at callback (build/userver.js:80:56)
```

Related: https://github.com/socketio/engine.io/issues/637
---
 lib/userver.ts |  4 ++++
 test/server.js | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/lib/userver.ts b/lib/userver.ts
index 38c9b5a8..66fa4041 100644
--- a/lib/userver.ts
+++ b/lib/userver.ts
@@ -275,6 +275,10 @@ class ResponseWrapper {
     this.res.end(data);
   }
 
+  public onData(fn) {
+    this.res.onData(fn);
+  }
+
   public onAborted(fn) {
     this.res.onAborted(fn);
   }
diff --git a/test/server.js b/test/server.js
index 3aff7c0e..d7d64428 100644
--- a/test/server.js
+++ b/test/server.js
@@ -3552,6 +3552,31 @@ describe("server", () => {
         }
       );
     });
+
+    it("should work with CORS enabled", done => {
+      engine = listen(
+        { cors: { origin: true, headers: ["my-header"], credentials: true } },
+        port => {
+          const client = new ClientSocket(`ws://localhost:${port}`, {
+            transports: ["polling"]
+          });
+          engine.on("connection", socket => {
+            socket.on("message", msg => {
+              expect(msg).to.be("hey");
+              socket.send("holà");
+            });
+          });
+          client.on("open", () => {
+            client.send("hey");
+          });
+          client.on("message", msg => {
+            expect(msg).to.be("holà");
+            client.close();
+            done();
+          });
+        }
+      );
+    });
   });
 
   describe("wsEngine option", () => {