interfaces: use old dbus encoding

Due to backwards compatibility with old configurations, this is an easy
fix to bring back the old object paths.

Tests are provided to capture this behavior.

Change-Id: Ic89f2eb02bb908cf23b833b08fdca941bef2a07a
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>
diff --git a/test/meson.build b/test/meson.build
index eb82249..e864298 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -22,12 +22,14 @@
 test_sources = [
   '../physical.cpp',
   '../sysfs.cpp',
+  '../interfaces/internal_interface.cpp',
 ]
 
 tests = [
   'physical.cpp',
   'sysfs.cpp',
   'test_led_description.cpp',
+  'test_dbus_name.cpp',
 ]
 
 foreach t : tests
diff --git a/test/test_dbus_name.cpp b/test/test_dbus_name.cpp
new file mode 100644
index 0000000..d9afabe
--- /dev/null
+++ b/test/test_dbus_name.cpp
@@ -0,0 +1,59 @@
+/**
+ * Copyright © 2024 9elements
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "interfaces/internal_interface.hpp"
+#include "sysfs.hpp"
+
+#include <gtest/gtest.h>
+
+using namespace phosphor::led;
+using namespace phosphor::led::sysfs;
+
+TEST(DbusName, Has3Parts)
+{
+    LedDescr d = {"devicename", "color", "function"};
+
+    std::string name = interface::InternalInterface::getDbusName(d);
+
+    ASSERT_EQ("devicename_function_color", name);
+}
+
+TEST(DbusName, WithDash)
+{
+    LedDescr d = {"enclosure-identify", std::nullopt, std::nullopt};
+
+    std::string name = interface::InternalInterface::getDbusName(d);
+
+    ASSERT_EQ("enclosure_identify", name);
+}
+
+TEST(DbusName, With2Dashes)
+{
+    LedDescr d = {"enclosure-identify-fault", std::nullopt, std::nullopt};
+
+    std::string name = interface::InternalInterface::getDbusName(d);
+
+    ASSERT_EQ("enclosure_identify_fault", name);
+}
+
+TEST(DbusName, WithUnderscore)
+{
+    LedDescr d = {"enclosure_identify", std::nullopt, std::nullopt};
+
+    std::string name = interface::InternalInterface::getDbusName(d);
+
+    ASSERT_EQ("enclosure_identify", name);
+}