使用 mockito 测试周围的 try catch 方法

Question

我想知道如何测试此方法并强制异常“DataAccessResourceFailureException”，但我没有有效的方法。

我需要在“ProductRepositoryImpl”类中强制执行该异常。有什么想法吗？

ProductRepositoryImpl

  @Override
  public Product saveProduct(Product input) {
  try {
    return productRepositoryAdapter.saveProduct(input);
  } catch (DataAccessResourceFailureException e) {
    logger.error(ERROR_WHEN_SAVING_PRODUCT_DATA_DETAIL + e.getMessage());
  }
    return null;
  }

ProductRepositoryAdapter

  public Product saveProduct(Product input) throws DataAccessResourceFailureException {
    ProductData productData = UtilTransform.productToProductData(input);

    // This method throws exception when there's no connection
    Product createdProduct = productDataRepository.findSkuByCountry(input.getSku(), 
    input.getCountry());

    if (createdProduct == null) {
       return Product.fromModel(productDataRepository.save(productData));
    } else {
      logger.error(THE_PRODUCT_ALREADY_EXISTS_IN_THE_RECORDS);
    }
      return null;
  }

ProductDataRepository

public interface ProductDataRepository extends MongoRepository<ProductData, String> {

  @Query("{'sku': ?0, 'country': ?1}")
  public Product findSkuByCountry(String sku, String country);

  public Optional<ProductData> findById(ProductId id);
}

我的测试，我正在使用 mockito。

@Test
void saveProductException() {
  Mockito.when(productRepository.saveProduct(buildProduct())).thenReturn(buildProduct());
  Mockito.when(adapter.saveProduct(buildProduct())).
      thenThrow(DataAccessResourceFailureException.class);

  Assertions.assertThrows(DataAccessResourceFailureException.class, 
  () -> productRepository.saveProduct(buildProduct()));
}

错误：

org.opentest4j.AssertionFailedError: Expected org.springframework.dao.DataAccessResourceFailureException to be thrown, but nothing was thrown.

---

编辑。

我稍微改变了我的方法，使用这段代码（谢谢大家）我能够抛出异常，所以我的代码将返回 null。在检查我的 jacoco index.html 之后，我可以看到它成功覆盖了“异常”。

  @Test
  void saveProductException() {
    Product product = buildProduct();
    Mockito.when(adapter.saveProduct(product)).
       thenThrow(DataAccessResourceFailureException.class);
   Assertions.assertNull(productRepository.saveProduct(product));
  }

Answer 1

这似乎很可疑：

Mockito.when(   productRepository.saveProduct(buildProduct())   ).thenReturn(buildProduct());
. . .
Assertions.assertThrows(DataAccessResourceFailureException.class, 
        () ->   productRepository.saveProduct(buildProduct())   );

你是说，当productRepository.saveProduct(buildProduct()) 被调用时返回buildProduct()，但是你断言当它被调用时它应该抛出DataAccessResourceFailureException？

不妨试试这个：

@Test
void saveProductException() {
    // as NicoVanBelle recommends, ensure you're referencing the same product throughout this test
    Product product = buildProduct();
    Mockito.when(adapter.saveProduct(product).thenThrow(DataAccessResourceFailureException.class);

    // Also as NicoVanBelle points out, when your `adapter` throws, `saveProduct` will return `null`
    Assertions.assertThat(productRepository.saveProduct(product)).isNull();
}

Answer 2

我怀疑这里有两件事

1. 您已将 productRepository.saveProduct 设置为不抛出异常，然后断言它抛出异常

Assertions.assertThrows(DataAccessResourceFailureException.class, () -> productRepository.saveProduct(buildProduct()));

1. 您正在调用 buildProduct()，我假设它会返回新产品，但 mockito 会尝试检查参数是否相等，因此将其取出为 Product myProduct = buildProduct() 并使用 myProduct

@Test
void saveProductException() {
  Product myProduct = buildProduct();
  
    Mockito.when(productRepository.saveProduct(myProduct))
          .thenThrow(DataAccessResourceFailureException.class);;
  
    Mockito.when(adapter.saveProduct(buildProduct())).
      thenThrow(DataAccessResourceFailureException.class);

    Assertions.assertThrows(DataAccessResourceFailureException.class, 
         () -> productRepository.saveProduct(myProduct));
}