added unit test for fridge repo

src/test/java/ntnu/idatt2016/v233/SmartMat/repository/group/FridgeRepositoryTest.java

+package ntnu.idatt2016.v233.SmartMat.repository.group;
+
+import ntnu.idatt2016.v233.SmartMat.entity.group.Fridge;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@DataJpaTest
+class FridgeRepositoryTest {
+
+    @Autowired
+    FridgeRepository fridgeRepository;
+
+    @Autowired
+    TestEntityManager entityManager;
+    Fridge fridge;
+    @BeforeEach
+    void setUp() {
+        fridge = new Fridge();
+        fridge.setGroupId(1L);
+
+        entityManager.persist(fridge);
+    }
+
+
+    @Test
+    void shouldFindByGroupId() {
+        assertEquals(fridge, fridgeRepository.findByGroupId(fridge.getGroupId()).get());
+    }
+
+    @Test
+    void shouldNotFindByGroupId() {
+        assertFalse(fridgeRepository.findByGroupId(2L).isPresent());
+    }
+
+    @Test
+    void shouldSave() {
+        Fridge fridge2 = new Fridge();
+        fridge2.setGroupId(2L);
+        fridgeRepository.save(fridge2);
+        assertEquals(fridge2, fridgeRepository.findByGroupId(fridge2.getGroupId()).get());
+
+    }
+
+    @Test
+    void shouldFindAll() {
+        assertEquals(1, fridgeRepository.findAll().size());
+    }
+
+    @Test
+    void shouldFindById(){
+        assertEquals(fridge, fridgeRepository.findById(fridge.getFridgeId()).get());
+    }
+
+    @Test
+    void shouldNotFindById(){
+        assertFalse(fridgeRepository.findById(2L).isPresent());
+    }
+
+    @Test
+    void shouldDeleteById(){
+        fridgeRepository.deleteById(fridge.getFridgeId());
+        assertFalse(fridgeRepository.findById(fridge.getFridgeId()).isPresent());
+    }
+
+
+  
+}
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