Added junit and component testcases for the item and orders

src/test/java/com/ecom/controller/ItemControllerJunitTest.java

+package com.ecom.controller;
+
+import com.ecom.config.TestConfig;
+import com.ecom.model.Item;
+import com.ecom.repository.ItemRepository;
+import com.ecom.service.impl.ItemServiceImpl;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.mockito.ArgumentMatchers;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ContextConfiguration;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest(classes = {ItemController.class})
+public class ItemControllerJunitTest {
+
+    @Autowired
+    private ItemController itemController;
+
+    @MockBean
+    private ItemServiceImpl itemServiceImpl;
+
+    @DisplayName("This method will test the save method  it will mock db ")
+    @ParameterizedTest
+    @MethodSource("getItemSource")
+    public void saveTest(Item item){
+        when(itemServiceImpl.save(ArgumentMatchers.any(Item.class))).thenReturn(item);
+        ResponseEntity<Item> responseEntity =  itemController.save(item);
+        assertAll( "savetest",
+                ()-> assertEquals(responseEntity.getStatusCode(), HttpStatus.CREATED,()->"status should be 201")
+                ,()->assertEquals(responseEntity.getBody().getId(),1,()->"id should be mocked id only")
+        );
+    }
+
+    @DisplayName("This method will test the save method  it will mock db ")
+    @ParameterizedTest
+    @MethodSource("getItemSource")
+    public void saveNegativeTest(Item item){
+        when(itemServiceImpl.save(ArgumentMatchers.any(Item.class))).thenReturn(null);
+        ResponseEntity<Item> responseEntity =  itemController.save(item);
+        assertAll( "savetestnegative",
+                ()-> assertEquals(responseEntity.getStatusCode(), HttpStatus.INTERNAL_SERVER_ERROR,()->"status should be 500")
+                ,()->assertNull(responseEntity.getBody(),()->"body is null")
+        );
+    }
+
+    @DisplayName("This method will test the get method   it will mock db ")
+    @ParameterizedTest
+    @ValueSource(ints={1})
+    public void getByIdTest(int id){
+        Item response=mockItem();
+        when(itemServiceImpl.findById(ArgumentMatchers.anyInt())).thenReturn(Optional.of(response));
+        ResponseEntity<Optional<Item>> responseEntity = itemController.getById(id);
+        assertAll( "gettest",
+                ()-> assertEquals(responseEntity.getStatusCode(), HttpStatus.OK,()->"status should be 200")
+                ,()->assertNotNull(responseEntity.getBody(),()->"body is not null")
+        );
+    }
+
+
+    @DisplayName("This method will test the get method for negative scenario it will mock db ")
+    @ParameterizedTest
+    @ValueSource(ints={1})
+    public void getByIdTestNegative(int id){
+        Item response=mockItem();
+        when(itemServiceImpl.findById(ArgumentMatchers.anyInt())).thenReturn(Optional.ofNullable(null));
+        ResponseEntity<Optional<Item>> responseEntity = itemController.getById(id);
+        assertAll( "gettestnegative",
+                ()-> assertEquals(responseEntity.getStatusCode(), HttpStatus.NOT_FOUND,()->"status should be NotFound")
+                ,()->assertEquals(responseEntity.getBody(),Optional.empty(),()->"body is  null")
+        );
+    }
+
+
+    @DisplayName("This method will test the getAll method   it will mock db ")
+    @Test
+    public void getAllTest(){
+        List<Item> response=Arrays.asList(mockItem());
+        when(itemServiceImpl.findAll()).thenReturn(response);
+        ResponseEntity<List<Item>> responseEntity = itemController.getAll();
+        assertAll( "getAllTest",
+                ()-> assertEquals(responseEntity.getStatusCode(), HttpStatus.OK,()->"status should be 200")
+                ,()->assertEquals(responseEntity.getBody(),response,()->"body is  List")
+        );
+    }
+
+
+    @DisplayName("This method will test the getAll method for Negeate test it will mock db ")
+    @Test
+    public void getAllTestNegative(){
+        List<Item> response=Arrays.asList(mockItem());
+        when(itemServiceImpl.findAll()).thenReturn(null);
+        ResponseEntity<List<Item>> responseEntity = itemController.getAll();
+        assertAll( "getAllTest",
+                ()-> assertEquals(responseEntity.getStatusCode(), HttpStatus.NOT_FOUND,()->"status should be Not found")
+                ,()->assertNull(responseEntity.getBody(),()->"body is  null")
+        );
+    }
+
+    private static Stream<Arguments> getItemSource(){
+        return Stream.of(Arguments.of(mockItem()));
+    }
+
+    public static Item mockItem() {
+        Item item=new Item();
+        item.setQty(1);
+        item.setId(1);
+        item.setName("test");
+        item.setPrice(1);
+        return item;
+    }
+
+
+}

src/test/java/com/ecom/service/ItemServiceImplTest.java

+package com.ecom.service;
+
+import com.ecom.model.Item;
+import com.ecom.repository.ItemRepository;
+import com.ecom.service.impl.ItemServiceImpl;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.mockito.ArgumentMatchers;
+
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest(classes = {ItemServiceImpl.class})
+@ExtendWith(SpringExtension.class)  //takes care of  all the spring  annotation test
+@ExtendWith(MockitoExtension.class)  // checks redundent mocking // also no need to add Mockito.initMock(this);
+public class ItemServiceImplTest {
+
+    @Autowired
+    private ItemServiceImpl itemServiceImpl;
+
+    @MockBean
+    private ItemRepository itemRepository;
+
+    @DisplayName("This method will test the save method  it will mock db ")
+    @ParameterizedTest
+    @MethodSource("getItemSource")
+    public void saveTest(Item item){
+        when(itemRepository.save(ArgumentMatchers.any(Item.class))).thenReturn(item);
+        Item itemResponse =  itemServiceImpl.save(item);
+        assertAll( "savetest",
+                ()-> assertEquals(itemResponse.getId(), item.getId(),()->"item id should be matched"),
+                ()-> assertEquals(itemResponse.getName(), item.getName(),()->"item name should be matched")
+
+        );
+    }
+
+    private static Stream<Arguments> getItemSource(){
+        return Stream.of(Arguments.of(mockItem()));
+    }
+
+    public static Item mockItem() {
+        Item item=new Item();
+        item.setQty(1);
+        item.setId(1);
+        item.setName("test");
+        item.setPrice(1);
+        return item;
+    }
+
+
+}