[ISSUE apache#1030] avoid to append unexpected separator to the last …

…message key

primitive/message.go

@@ -182,13 +182,7 @@ func (m *Message) WithTag(tags string) *Message {
 }
 
 func (m *Message) WithKeys(keys []string) *Message {
-	var sb strings.Builder
-	for _, k := range keys {
-		sb.WriteString(k)
-		sb.WriteString(PropertyKeySeparator)
-	}
-
-	m.WithProperty(PropertyKeys, sb.String())
+	m.WithProperty(PropertyKeys, strings.Join(keys, PropertyKeySeparator))
 	return m
 }
 

primitive/message_test.go

@@ -36,3 +36,13 @@ func TestMessageID(t *testing.T) {
 	}
 	t.Log(msgID)
 }
+
+func TestMessageKey(t *testing.T) {
+	msg := &Message{}
+	expected := "testKey"
+	msg.WithKeys([]string{expected})
+	actual := msg.GetKeys()
+	if actual != expected {
+		t.Fatalf("get message key error: expected is '%s', actual is '%s'", expected, actual)
+	}
+}