Added AllergyService unit tests

src/test/java/ntnu/idatt2016/v233/SmartMat/service/AllergyServiceTest.java

+package ntnu.idatt2016.v233.SmartMat.service;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+
+import ntnu.idatt2016.v233.SmartMat.dto.response.AllergyResponse;
+import ntnu.idatt2016.v233.SmartMat.entity.product.Allergy;
+import ntnu.idatt2016.v233.SmartMat.repository.AllergyRepository;
+
+import static org.mockito.Mockito.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+class AllergyServiceTest {
+
+    @InjectMocks
+    private AllergyService allergyService;
+
+    @Mock
+    private AllergyRepository allergyRepository;
+
+    @BeforeEach
+    void setUp() {
+        MockitoAnnotations.openMocks(this);
+    }
+
+    @Test
+    void testGetAllAllergies() {
+        Allergy allergy1 = new Allergy("Allergy1", "Description1", null, null);
+        Allergy allergy2 = new Allergy("Allergy2", "Description2", null, null);
+
+        when(allergyRepository.findAll()).thenReturn(Arrays.asList(allergy1, allergy2));
+
+        List<AllergyResponse> result = allergyService.getAllAllergies();
+
+        assertEquals(2, result.size());
+        assertEquals("Allergy1", result.get(0).getName());
+        assertEquals("Description1", result.get(0).getDescription());
+        assertEquals("Allergy2", result.get(1).getName());
+        assertEquals("Description2", result.get(1).getDescription());
+    }
+
+    @Test
+    void testGetAllergyByName() {
+        Allergy allergy = new Allergy("Allergy1", "Description1", null, null);
+
+        when(allergyRepository.findById("Allergy1")).thenReturn(Optional.of(allergy));
+
+        Optional<Allergy> result = allergyService.getAllergyByName("Allergy1");
+
+        assertTrue(result.isPresent());
+        assertEquals("Allergy1", result.get().getName());
+        assertEquals("Description1", result.get().getDescription());
+    }
+
+    @Test
+    void testSaveAllergy() {
+        Allergy allergy = new Allergy("Allergy1", "Description1", null, null);
+
+        allergyService.saveAllergy(allergy);
+
+        verify(allergyRepository, times(1)).save(allergy);
+    }
+
+    @Test
+    void testDeleteAllergyByName() {
+        allergyService.deleteAllergyByName("Allergy1");
+
+        verify(allergyRepository, times(1)).deleteById("Allergy1");
+    }
+}