Junit: expect / assertThrows doesn't work - java

How look my code, where exception was thrown:
(Lets say it is UserService.generate() )
try {
UrlDecoder.decode(someString); // invalid somestring here
...
} catch (UnsupportedEncodingException | RuntimeException e) {
customLogger("Exception message here");
}
How i am trying to catch this exception in test:
#Test(expected = IllegalArgumentExeception.class)
public void test() {
UserService u = new UserService();
u.generate("invalidString");
}
RESULT:
//info logs here
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "^I"
//Exception details here
java.lang.AssertionError: Expected exception: java.lang.IllegalArgumentException

The javadoc for URLDecoder.decode(someString) states that it will not throw an exception. I believe you meant to use URLDecoder.decode(someString, StandardCharsets.UTF_8.name()). But the Unsupported encoding exception is only thrown if the Charset you ask for is not supported. Here's one way you can make the exception get thrown, along with a way to check that it was thrown. This answer uses Mockito, which is a very powerful mocking framework.
import org.mockito.Mockito;
public class UserService {
public void generate(String someString, String encoding) {
try {
URLDecoder.decode(someString, encoding);
} catch (UnsupportedEncodingException e) {
customLogger("Exception message here");
}
}
public void customLogger(String string) {
// Do something
}
}
#Test
public void testThrowsOnBadEncoding() {
UserService u = Mockito.spy(new UserService());
u.generate("vl%23%46", "unknown");
Mockito.verify(u).customLogger("Exception message here");
}

Related

How to unit test the catch exception statement?

How do I test the catch statement below? My coverlay is failing and I am not sure how to cover this line.
public Method execute(#NonNull final String test) throws ServiceException {
try {
object = javaClient.fetchInfo(test);
} catch (ClientException | InternalServerError e) {
throw serviceExceptionAdapter.apply(e);
}
return object;
}
This is currently what I have in my test file:
#BeforeEach
void setup() {
this.serviceExceptionAdapter = mock(ExceptionAdapter.class);
this.mockJavaClient = mock(JavaClient.class);
proxy = new Proxy(mockJavaClient, serviceExceptionAdapter);
}
#Test
void test_InternalServerError() {
when(mockJavaClient.fetchInfo(any())).thenThrow(InternalServerError.class);
when(serviceExceptionAdapter.apply(any())).thenThrow(ServiceException.class);
assertThrows(ServiceException.class, () -> proxy.execute(test));
verify(serviceExceptionAdapter, times(1)).apply(any());
}
I have to guess a little bit, as you didn't provide a full working example. From what I see in your catch block
} catch (ClientException | InternalServerError e) {
throw serviceExceptionAdapter.apply(e);
}
you expect the return value of your .apply(e) function to be an exception and throw that exception. In your test however, your mocked serviceExceptionAdapter doesn't return an Exception, but throws one instead:
when(serviceExceptionAdapter.apply(any()))
.thenThrow(ServiceException.class);
If my interpretations are correct, your code should work if you change the mentioned line in the test to the following:
when(serviceExceptionAdapter.apply(any()))
.thenReturn(new ServiceException(...));

JUnit test not catching exception

UPDATE: Here's the full test:
#Test(expected = NullPointerException.class)
public void testMissingData() throws Exception{
Resource<ObjectDataModel, Content, Status> resource = builder.build(content, argA1Response,
argA2Response, objFilterParam, argA3Response);}
And here's the build method:
public Resource<ObjectDataModel, Content, Status> build(Content argContent,
ResponseA1 argA1Response,
ResponseA2 argA2Response, String argObjectTypeFilter,
ResponseA3 argA3Response) {
try {
viewDataModel.setObjectType(this.buildObjectType(filteredObjectType,
argA1Response.getData().getDataObject().getCategories().get(0).getObjectTypes().get(0)));
}
catch (Exception e) {
String msg = "Exception occoured while buildng the Object Data Model";
LOG.error(msg, e);
}
// we have the required information gathered to return
return Resource.okFromDataAndContent(viewDataModel, argContent);
}
And here's the buildObjectType() method:
private ObjectType buildObjectType(ObjectTypes argA1ProductType,
PendingObjectTypes argA2ProductType) {
ProductType objectType = new ObjectType();
List<Plan> plans = argA1ObjectType.getPlan();
List<PendingObjectSummary> objPlans = argA1ObjectType.getData();
if (objectType.getData() == null) {
objectType.setData(new ArrayList<>());
}
PendingObjectSummary tempPlan = null;
for (Plan currPlan : plans) {
tempPlan = plans.stream()
.filter(plan -> plan.getObjId().equals(currPlan.getObjId()))
.findFirst()
.orElseThrow(NullPointerException::new);
}
return objectType;
}
I'm using an Optional to test for null and I can confirm that the exception is being thrown -- but JUnit isn't catching it. Here's the test case:
#Test(expected = NullPointerException.class)
public void testMissingData() throws Exception{
Object<> response = fixture.create();
assertNotNull(response);
assertNotNull(response.getData());
assertNull(resource.getData().getObjectType());
}
In my create method I'm simply iterating over a bunch of objects to try and find one that matches my ID; if not found then throw a NullPointerException:
for (Object currObj : objects) {
tempObj = myOtherCollection.stream()
.filter(obj -> obj.getId().equals(currObj.getId()))
.findFirst()
.orElseThrow(NullPointerException::new);
}
The JUnit output clearly isn't catching the exception - here's the output:
java.lang.AssertionError: Expected exception: java.lang.NullPointerException
And my tomcat logs are definitely throwing the exception here:
18:48:30.015 [main] ERROR com.myCompany.src.ModelBuilder - Exception occoured while buildng the Data Model
java.lang.NullPointerException: null
at java.util.Optional.orElseThrow(Optional.java:290)
The only issue I can see is that maybe where I assign tempObj that the code is wrong. Am I missing anything obvious? Thanks for any helpful tips.
You are catching the nullpointer exception so the exception is not propagated to your test.
see
try {
viewDataModel.setObjectType(this.buildObjectType(filteredObjectType,
argA1Response.getData().getDataObject().getCategories().get(0).getObjectTypes().get(0)));
}
catch (Exception e) {
String msg = "Exception occoured while buildng the Object Data Model";
LOG.error(msg, e);
}
If you want to test for an exception you could throw an exception in your error handling (for example a custom ObjectCreationExcepion) and assert that that one is thrown, like
try {
viewDataModel.setObjectType(this.buildObjectType(filteredObjectType,
argA1Response.getData().getDataObject().getCategories().get(0).getObjectTypes().get(0)));
}
catch (Exception e) {
String msg = "Exception occoured while buildng the Object Data Model";
LOG.error(msg, e);
throw new ObjectCreationException(msg);
}
and in your test
#Test(expected = ObjectCreationException.class)
public void testMissingData() throws Exception{
Object<> response = fixture.create();
}
#Test(expected = ObjectCreationException.class) only handles exceptions that are not handled within the tested code OR the test itself.
So what you could do is
public Resource<ObjectDataModel, Content, Status> build(Content argContent,
ResponseA1 argA1Response,
ResponseA2 argA2Response, String argObjectTypeFilter,
ResponseA3 argA3Response) throws NullPointerExceptions // << notice thrwoing declatration
{ // do some stuf}
and then in test you can handle it like you where trying by
public void testMissingData() throws Exception{
Resource<ObjectDataModel, Content, Status> resource = builder.build(content, argA1Response,
argA2Response, objFilterParam, argA3Response);
}

How to test exception is thrown with Junit [duplicate]

This question already has answers here:
JUnit right way of test expected exceptions
(4 answers)
Closed 5 years ago.
I would like to know how I can write a unit test to get the catch block covered for the following method. The FOM.create(data) is a static method.
public String getValue(Data data) {
try {
return FOM.create(data);
} catch (UnsupportedEncodingException e) {
log.error("An error occured while creating data", e);
throw new IllegalStateException(e);
}
}
Currently this is my unit test but it doesn't hit the catch block:
#Test (expected = UnsupportedEncodingException.class)
public void shouldThrowUnsupportedEncodingException() {
doThrow(UnsupportedEncodingException.class).when(dataService).getUpdatedJWTToken(any(Data.class));
try {
dataService.getValue(data);
}catch (IllegalStateException e) {
verify(log).error(eq("An error occured while creating data"), any(UnsupportedEncodingException.class));
throw e;
}
}
You can check throwable exception if exception does not caught before unit test. In your case you cant check UnsupportedEncodingException but can check IllegalStateException.
Unit test must looks like:
#Test (expected = IllegalStateException.class)
public void shouldThrowIllegalStateException() {
dataService.getValue(data);
}
if you wanna to check UnsupportedEncodingException you must testing FOM.create(data) method
You can use JUnits exception rule like this:
public class SimpleExpectedExceptionTest {
#Rule
public ExpectedException thrown= ExpectedException.none();
#Test
public void throwsExceptionWithSpecificType() {
thrown.expect(NullPointerException.class);
thrown.expectMessage("Substring in Exception message");
throw new NullPointerException();
}
}

Testing methods using JUnit

I am new to JUnit and I have to test a method using JUnit api. One method internall calls another. My test case goes inside the method but while catchign the exception it fails.
Method under test is
public void checkANDCondition( Map<String, Message> messagesMap ) throws EISClientException
{
List<String> codes = getMessageCodes();
if(isAllReturnedMessagesContainCodes(codes, messagesMap))
{
StringBuffer buff = new StringBuffer("All of the specified message codes matched returned errors.");
for(String code: codes )
{
Message message = messagesMap.get(code);
buff.append(message.getMessageCode() + ": " + message.getMessageType() + ": " + message.getMessageText() + " ");
}
throw new EISClientException(buff.toString());
}
}
public boolean isAllReturnedMessagesContainCodes(List<String> codes, Map<String, Message> messagesMap)
{
if(codes!=null)
{
for(String code: codes)
{
if(!messagesMap.containsKey(code))
{
return false;
}
}
}
return true;
}
What I have done so far is
#Test
public void testPostProcess() throws Exception {
clientResponse = mock(ClientResponse.class);
MessageToExceptionPostProcessFilter postProcessFilter = new MessageToExceptionPostProcessFilter();
RetrieveBillingServiceResponse serviceResponse = new RetrieveBillingServiceResponse();caughtException = false;
try {
postProcessFilter.setCondition(ConditionOperator.AND);
List<String> messagesCodes = new ArrayList<String>();
messagesCodes.add("200");
messagesCodes.add("400");
Message message = new Message();
message.setMessageCode("200");
message.setMessageType(MessageTypeEnum.MESSAGE_TYPE_INFO);
message.setMessageText("Service completed successfully");
serviceResponse.setMessages(Arrays.asList(message));
postProcessFilter.setMessageCodes(messagesCodes);
serviceResponse = postProcessFilter.postProcess(serviceResponse, clientResponse);
assertNotNull(serviceResponse.getMessages());
} catch (EISClientException ex) {
caughtException = true;
assertEquals("All of the specified message codes matched returned errors.", ex.getMessage());
}
assertTrue(caughtException);
}
How can I make it pass?
Thanks
#Test(expected = EISCLientException.class)
public void testPostProcess() throws Exception {
...
serviceResponse.getMessages();
fail("Shouldn't reach this point");
}
That way you don't need to catch, with expected if it does not get throw a EISClientException it will fail.
edit: There are two times I can think of where you wouldn't want to use this.
1) You are mocking exceptions that are thrown mock(exception.class);
this i believe then throws some Mockito excpetion and it will not match the expected exception.
2) You are wrapping caught exceptions in your code, and throwing a generic exception. Example of code:
try {
} catch (FileParseException e){
throw new (ProjectFailingException(e, "file is bad");
}
if you have multiple catches and are wrapping them as ProjectFailingExceptions then you may want to catch in the test like this...
#Test ( expected = FileParseException.class)
public void testProcess() {
try {
...
} catch (ProjectFailingException e){
throw e.getCause();
}
Then the proper exception is thrown and you can make sure that process isn't throwing an exception from a a different catch.

Throws own exception from validate in android simple framework

I am using Simple XML in my project and have following problem
Source code
#Root (name = "Test")
#Order (elements = { "UserName", .... })
public class Test
{
#Element
public String UserName;
#Validate
public void validate() throws Exception
{
if(UserName.length() > 10) {
throw new Exception("User ID is invalid");
}
}
};
In the main code I write something like this
try {
serializer.read(REQ.class, reader);
}
catch(Exception ex) {
Log.i(TAG, ex.getMessage()); <--- HERE I GET MESSAGE: null, not the one I throws.
}
Question
Look like I can't catch exception which I throws, like validate function get my exception and replace it with it's own one. So am I right and what I can do to throw my own exception?
Thank you G.BlakeMeike you were right, the solution is follow:
try {
serializer.read(REQ.class, reader);
}
catch(Exception ex) {
Log.i(TAG, ex.getCause().getMessage());
}

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