JUnit爲try和catch塊覆蓋率

Question

我想爲下面的代碼寫一個JUnit，但我沒有得到任何想法如何涵蓋寫在catch塊語句中的代碼。請任何人爲下面的代碼寫一個示例JUnit。

在這裏，我不想覆蓋任何異常，但不想覆蓋使用Mockito編寫的catch代碼行代碼。

public Product getProductLookUpData() { 

     Product product = null; 
     try{ 
      // Try to get value from cacheable method 
      product = productCacheDao.getProductLookUpData(); 
      .....//statements 
     } catch (Exception ex) { 
      // getting value from db 
      product = productDao.getIpacMetricCodeLookUpData(); 
      ....//statements 
     } 

     return product; 
    } 

Answer 1

您可以mock都productCacheDao和productDao和檢查這些方法進行了多少次在你的測試用例調用。你可以模擬異常與模仿對象拋出，就像這樣：

when(mockObject.method(any())).thenThrow(new IllegalStateException()); 

所以，你的情況我會做這樣的事情：

import org.junit.Assert; 
import org.junit.Before; 
import org.junit.Test; 

import static org.mockito.Mockito.*; 

public class ProductTest { 
    private static final Product CACHED_PRODUCT = new Product("some parameters for cached product"); 
    private static final Product DB_PRODUCT = new Product("some parameters for DB product"); 

    private ProductService service; 
    private ProductDao productDaoMock; 
    private ProductCacheDao productCacheDaoMock; 

    @Before 
    public void setup() { 
     service = new ProductService(); 
     productDaoMock = mock(ProdoctDao.class); 
     service.setProductDao(productDaoMock); 

     productCacheDaoMock = mock(ProdoctCacheDao.class); 
     service.setProductCacheDao(productCacheDaoMock); 
    } 

    @Test 
    public void testCache() { 
     when(productCacheDaoMock.getProductLookUpData(any())).thenReturn(CACHED_PRODUCT); 

     final Product product = service.getProductLookUpData(); 

     Assert.assertEquals(CACHED_PRODUCT, product); 
     verify(productCacheDaoMock, times(1)).getProductLookUpData(any()); 
     verify(productDaoMock, never()).getIpacMetricCodeLookUpData(any()); 
    } 

    @Test 
    public void testDB() { 
     when(productCacheDaoMock.getProductLookUpData(any())).thenThrow(new IllegalStateException()); 
     when(productDaoMock.getIpacMetricCodeLookUpData(any())).thenReturn(DB_PRODUCT); 

     final Product product = service.getProductLookUpData(); 

     Assert.assertEquals(DB_PRODUCT, product); 
     verify(productCacheDaoMock, times(1)).getProductLookUpData(any()); 
     verify(productDaoMock, times(1)).getIpacMetricCodeLookUpData(any()); 
    } 
} 

Answer 2

你可以用嘲諷框架，如Mockito

在你的JUnit測試中，你可以做類似

public class YourTest { 

    private ProductcacheDao productCacheDaoMock; 

    @Before 
    public void setup() throws Exception { 

    productCacheDaoMock = Mockito.mock(ProductcacheDao.class); 

    } 

    @org.junit.Test 
    public void test() { 
     // Given 
     Mockito.when(productCacheDaoMock.getProductLookUpData()).thenThrow(new RuntimeException()); 

     // When 
     // do your stuff 
     productCacheDaoMock.getProductLookUpData(); 

     // Then 
     // ... 
    } 

} 

Answer 3

Mockito，或另一個模擬框架可以使用。你將需要兩個測試用例 - 有和沒有拋出異常。你可以模擬你的DAO返回一個已知的對象，這樣你就可以驗證你的服務正在展現正確的行爲。

我已經在下面寫了一個完整的例子。

public class MocksExample { 

    private ProductService service; 
    @Mock 
    private ProductDao productDao; 
    @Mock 
    private ProductCacheDao productCacheDao; 
    @Mock 
    private Product product; 

    @Before 
    public void setup() { 
     MockitoAnnotations.initMocks(this); 
     service = new ProductService(); 
     service.setProductCacheDao(productCacheDao); 
     service.setProductDao(productDao); 
    } 

    @Test 
    public void serviceReturnsProduct() { 
     when(productCacheDao.getProductLookUpData()).thenReturn(product); 
     assertThat(service.getProductLookUpData(), is(product)); 
    } 

    @Test 
    public void ipacProductReturnedWhenDaoThrowsException() { 
     when(productDao.getIpacMetricCodeLookUpData()).thenReturn(product); 
     when(productCacheDao.getProductLookUpData()).thenThrow(new IllegalStateException("foo")); 
     assertThat(service.getProductLookUpData(), is(product)); 
    } 
}