fix(hub): synchronise WebSocket connection access (#2453)

Co-authored-by: user01010111 <lapses.50.booster@icloud.com>

internal/hub/ws/ws_lifecycle_test.go

@@ -0,0 +1,64 @@
+//go:build testing
+
+package ws
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/blang/semver"
+	"github.com/henrygd/beszel/internal/common"
+	"github.com/lxzan/gws"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWsConnConcurrentClose(t *testing.T) {
+	connections := make(chan *WsConn, 1)
+	serverDone := make(chan struct{})
+	upgrader := gws.NewUpgrader(&Handler{}, &gws.ServerOption{})
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer close(serverDone)
+		conn, err := upgrader.Upgrade(w, r)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		ws := NewWsConnection(conn, semver.MustParse("0.12.10"))
+		conn.Session().Store("wsConn", ws)
+		connections <- ws
+		conn.ReadLoop()
+	}))
+	defer server.Close()
+	client, _, err := gws.NewClient(&gws.BuiltinEventHandler{}, &gws.ClientOption{
+		Addr: "ws" + strings.TrimPrefix(server.URL, "http"),
+	})
+	require.NoError(t, err)
+	defer client.WriteClose(1000, nil)
+	ws := <-connections
+	require.True(t, ws.IsConnected())
+
+	readerReady := make(chan struct{})
+	readerDone := make(chan struct{})
+	go func() {
+		defer close(readerDone)
+		close(readerReady)
+		for {
+			select {
+			case <-serverDone:
+				return
+			default:
+				ws.IsConnected()
+			}
+		}
+	}()
+	<-readerReady
+	require.NoError(t, client.WriteClose(1000, nil))
+	<-readerDone
+
+	require.False(t, ws.IsConnected())
+	require.ErrorIs(t, ws.Ping(), gws.ErrConnClosed)
+	require.ErrorIs(t, ws.sendMessage(common.HubRequest[any]{}), gws.ErrConnClosed)
+	ws.Close(nil)
+}