[release/8.0][browser] WebSocket works differently depending on if we look up its state or not

src/libraries/Common/tests/System/Net/Prerequisites/NetCoreServer/Handlers/EchoWebSocketHandler.cs

@@ -144,6 +144,18 @@ await socket.CloseAsync(
                     {
                         await Task.Delay(5000);
                     }
+                    else if (receivedMessage == ".receiveMessageAfterClose")
+                    {
+                        byte[] buffer = new byte[1024];
+                        string message = $"{receivedMessage} {DateTime.Now.ToString("HH:mm:ss")}";
+                        buffer = System.Text.Encoding.UTF8.GetBytes(message);
+                        await socket.SendAsync(
+                            new ArraySegment<byte>(buffer, 0, message.Length),
+                            WebSocketMessageType.Text,
+                            true,
+                            CancellationToken.None);
+                        await socket.CloseAsync(WebSocketCloseStatus.NormalClosure, receivedMessage, CancellationToken.None);
+                    }
                     else if (socket.State == WebSocketState.Open)
                     {
                         sendMessage = true;

src/libraries/System.Net.WebSockets.Client/src/System/Net/WebSockets/BrowserWebSockets/BrowserInterop.cs

@@ -19,11 +19,13 @@ internal static partial class BrowserInterop
         public static int GetReadyState(JSObject? webSocket)
         {
             if (webSocket == null || webSocket.IsDisposed) return -1;
-            int? readyState = webSocket.GetPropertyAsInt32("readyState");
-            if (!readyState.HasValue) return -1;
-            return readyState.Value;
+            return BrowserInterop.WebSocketGetState(webSocket);
         }
 
+        [JSImport("INTERNAL.ws_get_state")]
+        public static partial int WebSocketGetState(
+            JSObject webSocket);
+
         [JSImport("INTERNAL.ws_wasm_create")]
         public static partial JSObject WebSocketCreate(
             string uri,

src/libraries/System.Net.WebSockets.Client/src/System/Net/WebSockets/BrowserWebSockets/BrowserWebSocket.cs

@@ -385,12 +385,6 @@ private void CreateCore(Uri uri, List<string>? requestedSubProtocols)
 #endif
                         _closeStatus = (WebSocketCloseStatus)code;
                         _closeStatusDescription = reason;
-                        _closeReceived = true;
-                        WebSocketState state = State;
-                        if (state == WebSocketState.Connecting || state == WebSocketState.Open || state == WebSocketState.CloseSent)
-                        {
-                            FastState = WebSocketState.Closed;
-                        }
 #if FEATURE_WASM_THREADS
                     } //lock
 #endif

src/libraries/System.Net.WebSockets.Client/tests/CloseTest.cs

@@ -8,6 +8,7 @@
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Linq;
 
 using Xunit;
 using Xunit.Abstractions;
@@ -264,8 +265,8 @@ public async Task CloseOutputAsync_ClientInitiated_CanReceive_CanClose(Uri serve
 
         [ActiveIssue("https://github.com/dotnet/runtime/issues/28957", typeof(PlatformDetection), nameof(PlatformDetection.IsNotBrowser))]
         [OuterLoop("Uses external servers", typeof(PlatformDetection), nameof(PlatformDetection.LocalEchoServerIsNotAvailable))]
-        [ConditionalTheory(nameof(WebSocketsSupported)), MemberData(nameof(EchoServers))]
-        public async Task CloseOutputAsync_ServerInitiated_CanReceive(Uri server)
+        [ConditionalTheory(nameof(WebSocketsSupported)), MemberData(nameof(EchoServersWithSwitch))]
+        public async Task CloseOutputAsync_ServerInitiated_CanReceive(Uri server, bool delayReceiving)
         {
             string message = "Hello WebSockets!";
             var expectedCloseStatus = WebSocketCloseStatus.NormalClosure;
@@ -281,6 +282,10 @@ await cws.SendAsync(
                     true,
                     cts.Token);
 
+                // let server close the output before we request receiving
+                if (delayReceiving)
+                    await Task.Delay(1000);
+
                 // Should be able to receive the message echoed by the server.
                 var recvBuffer = new byte[100];
                 var segmentRecv = new ArraySegment<byte>(recvBuffer);
@@ -367,6 +372,43 @@ await cws.SendAsync(
             }
         }
 
+        public static IEnumerable<object[]> EchoServersWithSwitch =>
+            EchoServers.SelectMany(server => new List<object[]>
+            {
+                new object[] { server[0], true },
+                new object[] { server[0], false }
+            });
+
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/28957", typeof(PlatformDetection), nameof(PlatformDetection.IsNotBrowser))]
+        [ConditionalTheory(nameof(WebSocketsSupported)), MemberData(nameof(EchoServersWithSwitch))]
+        public async Task CloseOutputAsync_ServerInitiated_CanReceiveAfterClose(Uri server, bool syncState)
+        {
+            using (ClientWebSocket cws = await GetConnectedWebSocket(server, TimeOutMilliseconds, _output))
+            {
+                var cts = new CancellationTokenSource(TimeOutMilliseconds);
+                await cws.SendAsync(
+                    WebSocketData.GetBufferFromText(".receiveMessageAfterClose"),
+                    WebSocketMessageType.Text,
+                    true,
+                    cts.Token);
+
+                await Task.Delay(2000);
+
+                if (syncState)
+                {
+                    var state = cws.State;
+                    Assert.Equal(WebSocketState.Open, state);
+                    // should be able to receive after this sync
+                }
+
+                var recvBuffer = new ArraySegment<byte>(new byte[1024]);
+                WebSocketReceiveResult recvResult = await cws.ReceiveAsync(recvBuffer, cts.Token);
+                var message = Encoding.UTF8.GetString(recvBuffer.ToArray(), 0, recvResult.Count);
+
+                Assert.Contains(".receiveMessageAfterClose", message);
+            }
+        }
+
         [OuterLoop("Uses external servers", typeof(PlatformDetection), nameof(PlatformDetection.LocalEchoServerIsNotAvailable))]
         [ConditionalTheory(nameof(WebSocketsSupported)), MemberData(nameof(EchoServers))]
         public async Task CloseOutputAsync_CloseDescriptionIsNull_Success(Uri server)

src/mono/wasm/runtime/exports-internal.ts

@@ -8,7 +8,7 @@ import { http_wasm_supports_streaming_response, http_wasm_create_abort_controler
 import { exportedRuntimeAPI, Module, runtimeHelpers } from "./globals";
 import { get_property, set_property, has_property, get_typeof_property, get_global_this, dynamic_import } from "./invoke-js";
 import { mono_wasm_stringify_as_error_with_stack } from "./logging";
-import { ws_wasm_create, ws_wasm_open, ws_wasm_send, ws_wasm_receive, ws_wasm_close, ws_wasm_abort } from "./web-socket";
+import { ws_wasm_create, ws_wasm_open, ws_wasm_send, ws_wasm_receive, ws_wasm_close, ws_wasm_abort, ws_get_state } from "./web-socket";
 import { mono_wasm_get_loaded_files } from "./assets";
 import { jiterpreter_dump_stats } from "./jiterpreter";
 import { getOptions, applyOptions } from "./jiterpreter-support";
@@ -62,6 +62,7 @@ export function export_internal(): any {
         ws_wasm_receive,
         ws_wasm_close,
         ws_wasm_abort,
+        ws_get_state,
 
         // BrowserHttpHandler
         http_wasm_supports_streaming_response,

src/mono/wasm/runtime/web-socket.ts

@@ -43,6 +43,17 @@ function verifyEnvironment() {
     }
 }
 
+export function ws_get_state(ws: WebSocketExtension) : number
+{
+    if (ws.readyState != WebSocket.CLOSED)
+        return ws.readyState ?? -1;
+    const receive_event_queue = ws[wasm_ws_pending_receive_event_queue];
+    const queued_events_count = receive_event_queue.getLength();
+    if (queued_events_count == 0)
+        return ws.readyState ?? -1;
+    return WebSocket.OPEN;
+}
+
 export function ws_wasm_create(uri: string, sub_protocols: string[] | null, receive_status_ptr: VoidPtr, onClosed: (code: number, reason: string) => void): WebSocketExtension {
     verifyEnvironment();
     mono_assert(uri && typeof uri === "string", () => `ERR12: Invalid uri ${typeof uri}`);
@@ -175,8 +186,7 @@ export function ws_wasm_receive(ws: WebSocketExtension, buffer_ptr: VoidPtr, buf
         return null;
     }
 
-    const readyState = ws.readyState;
-    if (readyState == WebSocket.CLOSED) {
+    if (ws[wasm_ws_close_received]) {
         const receive_status_ptr = ws[wasm_ws_receive_status_ptr];
         setI32(receive_status_ptr, 0); // count
         setI32(<any>receive_status_ptr + 4, 2); // type:close