From 4642a135db65c4234d05b856014b3ce9afd941f6 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Sat, 25 Feb 2023 13:09:18 +0100
Subject: [PATCH 1/2] Protect client map by mutex

---
 server/socket.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/server/socket.go b/server/socket.go
index 1c83dcb94..c7d70c03e 100644
--- a/server/socket.go
+++ b/server/socket.go
@@ -6,6 +6,7 @@ import (
 	"math"
 	"net/http"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/evcc-io/evcc/util"
@@ -68,6 +69,8 @@ func ServeWebsocket(hub *SocketHub, w http.ResponseWriter, r *http.Request) {
 // SocketHub maintains the set of active clients and broadcasts messages to the
 // clients.
 type SocketHub struct {
+	mu sync.RWMutex
+
 	// Registered clients.
 	clients map[*SocketClient]bool
 
@@ -133,7 +136,9 @@ func kv(p util.Param) string {
 }
 
 func (h *SocketHub) welcome(client *SocketClient, params []util.Param) {
+	h.mu.Lock()
 	h.clients[client] = true
+	h.mu.Unlock()
 
 	var msg strings.Builder
 	msg.WriteString("{")
@@ -153,6 +158,9 @@ func (h *SocketHub) welcome(client *SocketClient, params []util.Param) {
 }
 
 func (h *SocketHub) broadcast(p util.Param) {
+	h.mu.RLock()
+	defer h.mu.RUnlock()
+
 	if len(h.clients) > 0 {
 		msg := "{" + kv(p) + "}"
 
@@ -173,10 +181,12 @@ func (h *SocketHub) Run(in <-chan util.Param, cache *util.Cache) {
 		case client := <-h.register:
 			h.welcome(client, cache.All())
 		case client := <-h.unregister:
+			h.mu.Lock()
 			if _, ok := h.clients[client]; ok {
 				close(client.send)
 				delete(h.clients, client)
 			}
+			h.mu.Unlock()
 		case msg, ok := <-in:
 			if !ok {
 				return // break if channel closed

From db98a34e234eb82299feaa9111601b9436fc4d84 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Sat, 25 Feb 2023 13:09:37 +0100
Subject: [PATCH 2/2] Improve encoding tests

---
 server/socket.go      | 10 ++++++----
 server/socket_test.go | 22 ++++++++++------------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/server/socket.go b/server/socket.go
index c7d70c03e..466cd2e8c 100644
--- a/server/socket.go
+++ b/server/socket.go
@@ -95,11 +95,11 @@ func encode(v interface{}) (string, error) {
 	var s string
 	switch val := v.(type) {
 	case time.Time:
-		var b []byte
-		if !val.IsZero() {
-			b, _ = val.Round(time.Second).Local().MarshalText()
+		if val.IsZero() {
+			s = "null"
+		} else {
+			s = fmt.Sprintf(`"%s"`, val.Format(time.RFC3339))
 		}
-		s = fmt.Sprintf(`"%s"`, string(b))
 	case time.Duration:
 		// must be before stringer to convert to seconds instead of string
 		s = fmt.Sprintf("%d", int64(val.Seconds()))
@@ -112,6 +112,8 @@ func encode(v interface{}) (string, error) {
 	default:
 		if b, err := json.Marshal(v); err == nil {
 			s = string(b)
+		} else {
+			return "", err
 		}
 	}
 	return s, nil
diff --git a/server/socket_test.go b/server/socket_test.go
index f6abef3f2..ffe7368f0 100644
--- a/server/socket_test.go
+++ b/server/socket_test.go
@@ -2,14 +2,18 @@ package server
 
 import (
 	"math"
-	"reflect"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestEncode(t *testing.T) {
+	now := time.Now()
+
 	tc := []struct {
-		in, out interface{}
+		in  interface{}
+		out string
 	}{
 		{int64(1), "1"},
 		{math.NaN(), "null"},
@@ -17,19 +21,13 @@ func TestEncode(t *testing.T) {
 		{"1.2345", "\"1.2345\""},
 		{time.Hour, "3600"},
 		{"minpv", "\"minpv\""},
+		{time.Time{}, "null"},
+		{now, "\"" + now.Format(time.RFC3339) + "\""},
 	}
 
 	for _, tc := range tc {
-		t.Logf("%+v", tc)
 		out, err := encode(tc.in)
-		if err != nil {
-			t.Error(err)
-		}
-
-		if out != tc.out {
-			t.Errorf("expected %v (string), got %v (%s)",
-				tc.out, out, reflect.TypeOf(out).Kind(),
-			)
-		}
+		assert.NoError(t, err)
+		assert.Equal(t, tc.out, out)
 	}
 }