lightclient: Fix wasm socket closure called after being dropped (#1289)

* lightclient: Close wasm socket while dropping from connecting state

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* lightclient: Construct one time only closures

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* testing: Enable console logs for lightclient WASM testing

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* lightclient: Separate wakes and check connectivity on poll_read

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* lightclient: Close the socket depending on internal state

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* Revert "lightclient: Separate wakes and check connectivity on poll_read"

This reverts commit 8660940.

* lightclient: Return pending if socket is opening from poll_read

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* lightclient: Close the socket on `poll_close`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* lightclient: Reset closures on Drop to avoid recursive invokation

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* lightclient: Close the socket if not already closing

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

---------

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

lightclient/src/platform/wasm_socket.rs

@@ -122,7 +122,7 @@ impl WasmSocket {
 
         let error_callback = Closure::<dyn FnMut(_)>::new({
             let inner = inner.clone();
-            move |_| {
+            move |_event: web_sys::Event| {
                 // Callback does not provide useful information, signal it back to the stream.
                 let mut inner = inner.lock().expect("Mutex is poised; qed");
                 inner.state = ConnectionState::Error;
@@ -136,7 +136,7 @@ impl WasmSocket {
 
         let close_callback = Closure::<dyn FnMut(_)>::new({
             let inner = inner.clone();
-            move |_| {
+            move |_event: web_sys::CloseEvent| {
                 let mut inner = inner.lock().expect("Mutex is poised; qed");
                 inner.state = ConnectionState::Closed;
 
@@ -171,6 +171,10 @@ impl AsyncRead for WasmSocket {
         let mut inner = self.inner.lock().expect("Mutex is poised; qed");
         inner.waker = Some(cx.waker().clone());
 
+        if self.socket.ready_state() == web_sys::WebSocket::CONNECTING {
+            return Poll::Pending;
+        }
+
         match inner.state {
             ConnectionState::Error => {
                 Poll::Ready(Err(io::Error::new(io::ErrorKind::Other, "Socket error")))
@@ -221,17 +225,30 @@ impl AsyncWrite for WasmSocket {
         Poll::Ready(Ok(()))
     }
 
-    fn poll_close(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
-        Poll::Ready(Ok(()))
+    fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+        if self.socket.ready_state() == web_sys::WebSocket::CLOSED {
+            return Poll::Ready(Ok(()));
+        }
+
+        if self.socket.ready_state() != web_sys::WebSocket::CLOSING {
+            let _ = self.socket.close();
+        }
+
+        let mut inner = self.inner.lock().expect("Mutex is poised; qed");
+        inner.waker = Some(cx.waker().clone());
+        Poll::Pending
     }
 }
 
 impl Drop for WasmSocket {
     fn drop(&mut self) {
-        let inner = self.inner.lock().expect("Mutex is poised; qed");
-
-        if inner.state == ConnectionState::Opened {
+        if self.socket.ready_state() != web_sys::WebSocket::CLOSING {
             let _ = self.socket.close();
         }
+
+        self.socket.set_onopen(None);
+        self.socket.set_onmessage(None);
+        self.socket.set_onerror(None);
+        self.socket.set_onclose(None);
     }
 }

testing/wasm-lightclient-tests/tests/wasm.rs

@@ -32,6 +32,8 @@ wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
 
 #[wasm_bindgen_test]
 async fn light_client_works() {
+    console_error_panic_hook::set_once();
+
     let api: LightClient<PolkadotConfig> = LightClientBuilder::new()
         .build_from_url("wss://rpc.polkadot.io:443")
         .await