diff --git a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/SwitchableStateTests.java b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/SwitchableStateTests.java
index 8fcd326..7ad5998 100644
--- a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/SwitchableStateTests.java
+++ b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/SwitchableStateTests.java
@@ -14,6 +14,7 @@ public class SwitchableStateTests {
     @BeforeEach
     public void createSwitchableState() {
         switchableState = new SwitchableState();
+        switchableState.setDevice(new RegularLight());
     }
 
     @Test
@@ -22,5 +23,10 @@ public class SwitchableStateTests {
         switchableState.setOn(true);
 
         assertTrue(switchableState.isOn());
+
+        switchableState.apply();
+        assertTrue(((Switchable) switchableState.getDevice()).isOn());
+
+        assertTrue(switchableState.copy().isOn());
     }
 }
diff --git a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/ThermostatServiceTests.java b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/ThermostatServiceTests.java
index 05a0447..978b157 100644
--- a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/ThermostatServiceTests.java
+++ b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/ThermostatServiceTests.java
@@ -10,6 +10,7 @@ import ch.usi.inf.sa4.sanmarinoes.smarthut.models.User;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.socket.SensorSocketEndpoint;
 import java.math.BigDecimal;
 import java.util.List;
+import java.util.Optional;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -63,4 +64,14 @@ public class ThermostatServiceTests {
         when(thermostatRepository.findAllByUsername("user")).thenReturn(List.of(t));
         assertThat(thermostatService.findAll("user")).containsExactly(t);
     }
+
+    @Test
+    public void testFindById() {
+        final Thermostat t = new Thermostat();
+        when(thermostatRepository.findByIdAndUsername(2L, "user")).thenReturn(Optional.empty());
+        when(thermostatRepository.findByIdAndUsername(1L, "user")).thenReturn(Optional.of(t));
+        doNothing().when(thermostatPopulationService).populateMeasuredTemperature(t);
+        assertThat(thermostatService.findById(2L, "user")).isEmpty();
+        assertThat(thermostatService.findById(1L, "user")).isNotEmpty();
+    }
 }