How to test loop inside loop in mockito - junit

Question

Hi i have method insertOrUpdateProductsToDB(Product product) is used to perform insert operation in database using catalogService of Broadleaf ,catalog Service is doing all saving operation in db . My method is expected restClient product as a parameter.After passing the restClient product we are converting this product into Broadleafproduct by using ProductConversion Class.In product conversion only setting is happening for converting rest Product into broadleafproduct. Now my requirement is to test this method using mockito but when i tried to do add these two line at the end of my test method
verify(mainProduct).getAdditionalSkus().add(sku);
verify(mainProduct).setProductOptions(productOptionList);
Its failing.
when i debug the code there is for loop inside for loop in the method insertOrUpdateProductsToDB(Product product) and i find productOption = catalogService.saveProductOption(productOption); here productOption is coming null so please tell how to test loop inside loop and same happening for
for (Sku skuWithProductOptions : productConversion.createSkuWithProductOptions(product, mainProduct,productOptionList)) {
catalogService.saveSku(skuWithProductOptions);
}
this line in the same method .kindly also check my test case whether i am doing right or not .
Class and insertOrUpdateProductsToDB(Product product) Method to be test
import com.admin.exception.AdminGenericException;
import com.admin.exception.AdminRestException;
import com.admin.util.helper.ProductConversion;
import com.admin.wrapper.getproducts.req.ObjectFactory;
import com.admin.wrapper.getproducts.resp.Product;
import com.admin.wrapper.getproducts.resp.Response;
import com.mycompany.rest.service.client.RestClientUtil;
import com.mycompany.util.constants.ApplicationConstants;
#Service
public class GetProductsServiceImpl {
private static final Logger logger = Logger.getLogger(GetProductsServiceImpl.class);
#Resource(name = "blCatalogService")
protected CatalogService catalogService;
public void setCatalogService(CatalogService catalogService) {
this.catalogService = catalogService;
}
protected RestClientUtil restClientUtil;
public void setRestClientUtil(RestClientUtil restClientUtil) {
this.restClientUtil = restClientUtil;
}
#Value("#{configProperties['salePriceRate']}")
private long salePriceRate;
public void setRetailPriceRate(long retailPriceRate) {
this.retailPriceRate = retailPriceRate;
}
#Value("#{configProperties['retailPriceRate']}")
private long retailPriceRate;
public void setSalePriceRate(long salePriceRate) {
this.salePriceRate = salePriceRate;
}
//Insertion/Update DB logic
public String insertOrUpdateProductsToDB(Product product) {
logger.debug("Start of : insertOrUpdateProductsToDB()");
try {
List<String> category = new ArrayList<String> (Arrays.asList(ApplicationConstants.CATEGORY));
ProductConversion productConversion = new ProductConversion();
List<ProductOption> productOptionList = new ArrayList<ProductOption>();
if (category.contains(product.getCategory().toUpperCase())) {
org.broadleafcommerce.core.catalog.domain.Product mainProduct=catalogService.createProduct(new ProductType("org.broadleafcommerce.core.catalog.domain.Product", "Normal Product"));
mainProduct = productConversion.createProduct(mainProduct,product);
Sku sku=catalogService.createSku();
mainProduct.setDefaultSku(sku);
mainProduct = productConversion.addSkuToProduct(mainProduct, product, salePriceRate,retailPriceRate);
for (ProductOption productOption : productConversion.createProductOptions(product, mainProduct)) {
productOption.setAllowedValues(productConversion.createProductOptionValues(product,productOption));
productOption = catalogService.saveProductOption(productOption);
productOptionList.add(productOption);
}
sku = catalogService.saveSku(mainProduct.getDefaultSku());
mainProduct.getAdditionalSkus().add(sku);
mainProduct.setProductOptions(productOptionList);
mainProduct = catalogService.saveProduct(mainProduct);
for (Sku skuWithProductOptions : productConversion.createSkuWithProductOptions(product, mainProduct,productOptionList)) {
catalogService.saveSku(skuWithProductOptions);
}
}
logger.debug("End of : insertOrUpdateProductsToDB()");
return "Product inserted into DB successfully";
}
catch (Exception e) {
logger.error("Error:", e);
return "Insertion of product into DB Failed ";
}
}
//Insertion service for DB
public String insertProductsIntoDB(){
logger.debug("Start of : insertProductsIntoDB()");
int insertionCount=0;
try{
com.admin.wrapper.getproducts.resp.Response resp = getAvailableProductsFromPBS();
for (Product product : resp.getProducts().getProduct()) {
if(catalogService.findProductById(Long.parseLong(product.getId()))==null){
String str=insertOrUpdateProductsToDB(product);
if(str.equalsIgnoreCase("Product inserted into DB successfully")){
insertionCount=insertionCount+1;
}
}
}
logger.debug(insertionCount+" Products inserted into DB successfully");
logger.debug("End of : insertProductsIntoDB()");
return insertionCount+" Products inserted into DB successfully";
}catch (AdminRestException e) {
logger.error("Error:", e);
return e.getMessage();
}
}
}
My test case class and method
public class GetProductsServiceImplTest {
private CatalogService catalogService;
private RestClientUtil restClientUtil;
private GetProductsServiceImpl getProductsServiceImpl;
private org.broadleafcommerce.core.catalog.domain.Product mainProduct;
private Sku sku;
private ProductOption productOption;
private List<ProductOption> productOptionList;
#Before
public void setUp() throws Exception {
catalogService = mock(CatalogService.class);
productOptionList=mock(List.class);
mainProduct = spy(new ProductImpl());
sku = new SkuImpl();
getProductsServiceImpl = new GetProductsServiceImpl();
getProductsServiceImpl.setCatalogService(catalogService);
productOption=mock(ProductOption.class);
restClientUtil = new RestClientUtil();
}
#Test
public void testInsertOrUpdateProductsToDB() {
restClientUtil.setSellerCode("1");
restClientUtil.setPbsUrl("http://10.52.165.239:8080/pbs");
getProductsServiceImpl.setRestClientUtil(restClientUtil);
Response pbsResponse = getProductsServiceImpl
.getAvailableProductsFromPBS();
for (Product pbsProduct : pbsResponse.getProducts().getProduct()) {
when(catalogService.createProduct(new ProductType("org.broadleafcommerce.core.catalog.domain.Product","Normal Product"))).thenReturn(mainProduct);
when(catalogService.createSku()).thenReturn(sku);
when(catalogService.saveProductOption(productOption)).thenReturn(productOption);
when(catalogService.saveSku(sku)).thenReturn(sku);
when(catalogService.saveProduct(mainProduct)).thenReturn(mainProduct);
when(catalogService.saveSku(sku)).thenReturn(sku);
getProductsServiceImpl.insertOrUpdateProductsToDB(pbsProduct);
verify(mainProduct,times(2)).setDefaultSku(sku);
verify(mainProduct).getAdditionalSkus().add(sku);
verify(mainProduct).setProductOptions(productOptionList);
break;
}
}
}
This is the error while testing
java.lang.NullPointerException
at com.admin.api.service.getproducts.test.GetProductsServiceImplTest.testInsertOrUpdateProductsToDB(GetProductsServiceImplTest.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)

Answer 1

I have a few remarks that probably won't answer your orignal question. But I hope they will guide you toward a better refactor of this code. Also the code sample you showed are not enough to point you at the exact issue ; it's an NPE in the test method so it should not be that difficult to track down.
That being said here's the point I'd like to raise
The test code is curiously crafted, and in my opinion this code are overusing Mockito. Overall this code looks way too complex to be correctly tested anyway. I don't think it was coded following TDD principle (TDD is really convenient when it comes to testing and designing the app)
You may want to follow the common guideline no more than 10 line of codes in a single method, this usually helps to separate concerns and identify simpler code / intents. These simpler code could be changed and tested more easily if designed correctly (without leaking concepts or variables). For example you may want to extract a method that saves a single Product and test only that one.
What's even more striking is that this code seems kinda procedural (even if inside objects). And doesn't really explain the intent in business words (ok it's about saving stuff in DB, but for which reason there's all this logic, this reason should appear in the method name).
The test and Mockito is weird, and the code should not iterate over the collection to stub then verify
for (Product pbsProduct : pbsResponse.getProducts().getProduct()) {
when(catalogService.createProduct(new ProductType("org.broadleafcommerce.core.catalog.domain.Product","Normal Product"))).thenReturn(mainProduct);
when(catalogService.createSku()).thenReturn(sku);
when(catalogService.saveProductOption(productOption)).thenReturn(productOption);
when(catalogService.saveSku(sku)).thenReturn(sku);
when(catalogService.saveProduct(mainProduct)).thenReturn(mainProduct);
when(catalogService.saveSku(sku)).thenReturn(sku);
getProductsServiceImpl.insertOrUpdateProductsToDB(pbsProduct);
verify(mainProduct,times(2)).setDefaultSku(sku);
verify(mainProduct).getAdditionalSkus().add(sku);
verify(mainProduct).setProductOptions(productOptionList);
break;
}
In pseudo code I would first try to extract the saving logic using the given/when/then BBDD keywords (they help to clarify what need to be tested in which scenario and context). Keep the fixture and assertions to a minimum, you would rather deal with multiple test method than multiple complex test methods.
#Test
public void ensure_product_is_saved_in_the_catalog() {
// given
Product a_simple_product = ProductBuilder.simpleProduct().build();
when(catalogService.doSomething(....))).thenReturn(mainProduct);
// when
productsService.saveProduct(product);
// then
verify(catalogService).doSomethingElseWith(mainProduct);
}
If assertion on product data is relevant in your test scenario, then write a test that actually test the data (using JUnit assertions, AssertJ, ...). Don't mock the Product !
And proceed gradually for each test, then refactor if need ed to keep the code manageable (extract a single method in another class if necessary, etc.)
You should definitely read the following books, they've helped a lot of programmers to get better code Clean Coder or Growing Object Oriented Software, Guided by Tests. This list is of course not exhaustive.
Hope that helps.