add a power interface and use that for lights

libguh/interfaces/interfaces.qrc

@@ -25,6 +25,7 @@
         <file>connectable.json</file>
         <file>inputtrigger.json</file>
         <file>outputtrigger.json</file>
+        <file>power.json</file>
     </qresource>
     <qresource prefix="/"/>
 </RCC>

libguh/interfaces/light.json

@@ -1,9 +1,3 @@
 {
-    "states": [
-        {
-            "name": "power",
-            "type": "bool",
-            "writable": true
-        }
-    ]
+    "extends": "power"
 }

libguh/interfaces/power.json

@@ -0,0 +1,9 @@
+{
+    "states": [
+        {
+            "name": "power",
+            "type": "bool",
+            "writable": true
+        }
+    ]
+}

tests/auto/devices/testdevices.cpp

@@ -241,11 +241,12 @@ void TestDevices::verifyInterfaces()
     QVERIFY(!mockDevice.isEmpty());
 
     QVariantList interfaces = mockDevice.value("interfaces").toList();
-    // Must contain gateway, light and battery, but must not contain mediacontroller as the device manager should filter
+    // Must contain gateway, power, light and battery, but must not contain mediacontroller as the device manager should filter
     // that away because it doesn't implement all the required states.
-    QCOMPARE(interfaces.count(), 3);
+    QCOMPARE(interfaces.count(), 4);
     QVERIFY(interfaces.contains("gateway"));
     QVERIFY(interfaces.contains("battery"));
+    QVERIFY(interfaces.contains("power"));
     QVERIFY(interfaces.contains("light"));
     QVERIFY(!interfaces.contains("mediacontroller"));
 }