added test

build.gradle

@@ -37,6 +37,7 @@ dependencies {
     // JUnit Jupiter
     testImplementation platform("org.junit:junit-bom:${versions.junit}")
     testImplementation "org.junit.jupiter:junit-jupiter"
+    testImplementation "org.mockito:mockito-core:${versions.mockito}"
 }
 
 checkstyle {

src/main/java/com/codeus/winter/config/impl/BeanDefinitionRegistryImpl.java

@@ -13,16 +13,16 @@ public class BeanDefinitionRegistryImpl implements BeanDefinitionRegistry {
     @Override
     public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition) {
         if (beanDefinitionMap.containsKey(beanName)) {
-            throw new BeanDefinitionStoreException("Cannot register bean definition with name '" + beanName +
-                    "': another bean with the same name already exists and overriding is not allowed.");
+            throw new BeanDefinitionStoreException(String.format("Cannot register bean definition with name '%s' " +
+                    "another bean with the same name already exists and overriding is not allowed.", beanName));
         }
         beanDefinitionMap.put(beanName, beanDefinition);
     }
 
     @Override
     public void removeBeanDefinition(String beanName) {
         if (!beanDefinitionMap.containsKey(beanName)) {
-            throw new BeanDefinitionStoreException("No bean definition found for name '" + beanName + "'");
+            throw new BeanDefinitionStoreException( String.format("No bean definition found for name '%s'", beanName));
         }
         beanDefinitionMap.remove(beanName);
     }

src/main/java/com/codeus/winter/context/AnnotationApplicationContext.java

@@ -1,10 +1,12 @@
 package com.codeus.winter.context;
 
 import com.codeus.winter.config.BeanDefinition;
+import com.codeus.winter.config.BeanDefinitionRegistry;
 import com.codeus.winter.config.BeanFactory;
 import com.codeus.winter.config.BeanPostProcessor;
 import com.codeus.winter.config.ClassPathBeanDefinitionScanner;
 import com.codeus.winter.config.DefaultBeanFactory;
+import com.codeus.winter.config.impl.BeanDefinitionRegistryImpl;
 import com.codeus.winter.exception.BeanNotFoundException;
 import jakarta.annotation.Nullable;
 import org.apache.commons.lang3.ObjectUtils;
@@ -24,15 +26,17 @@ public class AnnotationApplicationContext implements ApplicationContext, BeanFac
     private String displayName = ObjectUtils.identityToString(this);
     private final ClassPathBeanDefinitionScanner scanner;
     private final DefaultBeanFactory beanFactory;
+    private final BeanDefinitionRegistry beanDefinitionRegistry;
 
     /**
      * Constructs a new {@code AnnotationApplicationContext} for the specified base packages.
      *
      * @param basePackages the base packages to scan for component classes
      */
     public AnnotationApplicationContext(String... basePackages) {
+        this.beanDefinitionRegistry = new BeanDefinitionRegistryImpl();
         beanFactory = new DefaultBeanFactory();
-        this.scanner = new ClassPathBeanDefinitionScanner(beanFactory);
+        this.scanner = new ClassPathBeanDefinitionScanner(beanDefinitionRegistry);
         scanner.scanPackages(basePackages);
     }
 

src/test/java/com/codeus/winter/config/impl/BeanDefinitionRegistryImplTest.java

@@ -0,0 +1,71 @@
+package com.codeus.winter.config.impl;
+
+import com.codeus.winter.config.BeanDefinition;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class BeanDefinitionRegistryImplTest {
+    private BeanDefinitionRegistryImpl beanFactory;
+
+    @BeforeEach
+    void setUp() {
+        beanFactory = new BeanDefinitionRegistryImpl();
+    }
+
+    @Test
+    @DisplayName("Should create a bean using a mocked BeanDefinition")
+    void testCreateBeanWithMockBeanDefinition() {
+        BeanDefinition mockBeanDefinition = mock(BeanDefinition.class);
+        when(mockBeanDefinition.getBeanClassName()).thenReturn("test.MyTestBean");
+        when(mockBeanDefinition.isSingleton()).thenReturn(true);
+
+        beanFactory.registerBeanDefinition("testBean", mockBeanDefinition);
+
+        Object bean = beanFactory.getBeanDefinition("testBean");
+        assertNotNull(bean, "Bean should not be null");
+    }
+
+    @Test
+    @DisplayName("Should register and retrieve a BeanDefinition successfully")
+    void testRegisterAndRetrieveBeanDefinition() {
+        BeanDefinition mockBeanDefinition = mock(BeanDefinition.class);
+        when(mockBeanDefinition.getBeanClassName()).thenReturn("test.MyTestBean");
+
+        beanFactory.registerBeanDefinition("testBean", mockBeanDefinition);
+
+        BeanDefinition retrievedDefinition = beanFactory.getBeanDefinition("testBean");
+
+        assertNotNull(retrievedDefinition, "BeanDefinition should not be null");
+        assertEquals("test.MyTestBean", retrievedDefinition.getBeanClassName());
+    }
+
+    @Test
+    @DisplayName("Should check if a BeanDefinition exists in the registry")
+    void testContainsBeanDefinition() {
+        BeanDefinition mockBeanDefinition = mock(BeanDefinition.class);
+
+        beanFactory.registerBeanDefinition("testBean", mockBeanDefinition);
+
+        assertTrue(beanFactory.containsBeanDefinition("testBean"), "Registry should contain 'testBean'");
+        assertFalse(beanFactory.containsBeanDefinition("nonExistentBean"), "Registry should not contain 'nonExistentBean'");
+    }
+
+    @Test
+    @DisplayName("Should remove a BeanDefinition from the registry")
+    void testRemoveBeanDefinition() {
+        BeanDefinition mockBeanDefinition = mock(BeanDefinition.class);
+
+        beanFactory.registerBeanDefinition("testBean", mockBeanDefinition);
+        beanFactory.removeBeanDefinition("testBean");
+
+        assertFalse(beanFactory.containsBeanDefinition("testBean"), "Registry should not contain 'testBean' after removal");
+    }
+}

version.gradle

@@ -6,6 +6,7 @@ ext {
             'log4j': '2.23.1',
             'junit': '5.10.3',
             'checkstyle': '10.20.0',
-            'jacoco': '0.8.12'
+            'jacoco': '0.8.12',
+            'mockito': '5.5.0'
     ]
 }