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Junit 5: Expected exception to be thrown, but nothing was thrown

I have very strange behavior for the following test:
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.NoSuchElementException;
import java.util.stream.Stream;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
public class TestLogger {
static IPcdsLogger logger;
static Logger LOGGER = LoggerFactory.getLogger(TestLogger.class);
#BeforeEach
public void setup() {
logger = PcdsLoggerFactory.getLogger(TestLogger.class);
}
#AfterEach
public void tearDown() throws IOException {
PrintWriter writer = new PrintWriter(new File("src/test/resources/temp/test.log"));
writer.print("");
writer.close();
}
#AfterAll
public static void deleteFile() throws IOException {
logger.close();
FileUtils.deleteDirectory(new File("src/test/resources/temp"));
}
#Test
public void testJsonParams() throws IOException {
logger.builder()
.add("hello", "world")
.add("bob", "alice")
.debug("wtf");
assertEquals("world", readLine(0).get("hello"));
assertEquals("alice", readLine(0).get("bob"));
}
#Test
public void testLogLevelTraceCheck() {
logger.traceLevel()
.ifPresent(b -> b.add("hello", "world").trace());
assertThrows(NoSuchElementException.class, () -> readLine(0));
}
private JSONObject readLine(int lineNo) throws IOException {
try (Stream<String> lines = Files.lines(Paths.get("src/test/resources/temp/test.log"))) {
String line = lines.skip(lineNo).findFirst().get();
return new JSONObject(line);
}
}
When I run the test individually, it passes.
When I run all the tests, on the second run I get the following error for the testLogLevelTraceCheck:
Expected java.util.NoSuchElementException to be thrown, but nothing was thrown.
org.opentest4j.AssertionFailedError: Expected java.util.NoSuchElementException to be thrown, but nothing was thrown.
at app//org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:71)
at app//org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:37)
at app//org.junit.jupiter.api.Assertions.assertThrows(Assertions.java:3082)
I thought it was enough to reinstantiate the logger in #BeforeEach, but somehow it doesn't happen all the time this.
Do you have any suggestions?

If it does not throw, it could mean that the file is actually there and has some content. This makes sense, since just calling PcdsLoggerFactory.getLogger(TestLogger.class) does not seem to guarantee to delete the logfile then.

Test fails on a null pointer exception when I use #InjectMocks

I am practising restful api endpoints using https://api.predic8.de/shop/docs
Here is my repo
I am getting a NPE failure when I try to use #InjectMocks during my TDD approach
However, I can make my test pass when I make a direct call in the setup()
vendorService = new VendorServiceImpl(VendorMapper.INSTANCE, vendorRepository);
I wanted to extend my learning by trying to create an endpoint for getting all vendors.
When I employ TDD along the way, but, my test getAllVendors() fails on a NPE when I try to use #InjectMocks but passes when I substitute it for a direct call in the setup() method.
The NPE is linked to the mapper class I think.
Here are the classes that I believe are useful. VendorServiceTest, VendorServiceImpl, VendorMapper.
I have commented out the direct call in the setup as I want to get the test passing using #InjectMocks
package guru.springfamework.services;
import guru.springfamework.api.v1.mapper.VendorMapper; import
guru.springfamework.api.v1.model.VendorDTO; import
guru.springfamework.domain.Vendor; import
guru.springfamework.repositories.VendorRepository; import
org.junit.Before; import org.junit.Test; import
org.mockito.InjectMocks; import org.mockito.Mock; import
org.mockito.MockitoAnnotations; import
org.springframework.test.web.servlet.MockMvc;
import java.util.Arrays; import java.util.List;
import static org.junit.Assert.*; import static
org.mockito.Mockito.when;
public class VendorServiceTest {
public static final String NAME = "Tasty";
public static final Long ID = 1L;
#Mock
VendorMapper vendorMapper;
#Mock
VendorRepository vendorRepository;
#InjectMocks
VendorServiceImpl vendorService;
//VendorService vendorService;
#Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks(this);
//vendorService = new VendorServiceImpl(VendorMapper.INSTANCE, vendorRepository);
}
#Test
public void getAllVendors() {
//given
List<Vendor> vendors = Arrays.asList(new Vendor(), new Vendor(), new Vendor());
when(vendorRepository.findAll()).thenReturn(vendors);
//when
List<VendorDTO> vendorDTOList = vendorService.getAllVendors();
//then
assertEquals(3, vendorDTOList.size());
}
#Test
public void findByName() {
}
}
package guru.springfamework.services;
import guru.springfamework.api.v1.mapper.VendorMapper; import
guru.springfamework.api.v1.model.VendorDTO; import
guru.springfamework.repositories.VendorRepository; import
org.springframework.stereotype.Service;
import java.util.List; import java.util.stream.Collectors;
#Service public class VendorServiceImpl implements VendorService {
private final VendorMapper vendorMapper;
private final VendorRepository vendorRepository;
public VendorServiceImpl(VendorMapper vendorMapper, VendorRepository vendorRepository) {
this.vendorMapper = vendorMapper;
this.vendorRepository = vendorRepository;
}
#Override
public List<VendorDTO> getAllVendors() {
return vendorRepository
.findAll()
.stream()
.map(vendor -> {
VendorDTO vendorDTO = vendorMapper.vendorToVendorDTO(vendor);
vendorDTO.setVendorUrl("/api/v1/vendors/" + vendor.getId());
return vendorDTO;
})
.collect(Collectors.toList());
}
#Override
public VendorDTO findByName(String name) {
return vendorMapper.vendorToVendorDTO(vendorRepository.findByName(name));
}
#Override
public VendorDTO getVendorById(Long id) {
return vendorMapper.vendorToVendorDTO(vendorRepository.findById(id).orElseThrow(RuntimeException::new));
}
}
package guru.springfamework.api.v1.mapper;
import guru.springfamework.api.v1.model.VendorDTO; import
guru.springfamework.domain.Vendor; import org.mapstruct.Mapper; import
org.mapstruct.factory.Mappers;
#Mapper public interface VendorMapper {
VendorMapper INSTANCE = Mappers.getMapper(VendorMapper.class);
VendorDTO vendorToVendorDTO(Vendor vendor);
}
Does anyone know where and why I am going wrong?

The problem is that you created mock object for the mapper, but you didn't say what should happen when the method vendorToVendorDTO is called.
Therefore, when that method is called in the next line of code:
VendorDTO vendorDTO = vendorMapper.vendorToVendorDTO(vendor);
It will return null, and then in this line of code:
vendorDTO.setVendorUrl("/api/v1/vendors/" + vendor.getId());
You will get NullPointerException.
To make this work, change your getAllVendors() method as follows:
#Test
public void getAllVendors() {
//given
List<Vendor> vendors = Arrays.asList(new Vendor(), new Vendor(), new Vendor());
VendorDTO mockDto = mock(VendorDTO.class);
when(vendorRepository.findAll()).thenReturn(vendors);
when(vendorMapper.vendorToVendorDTO(any(Vendor.class))).thenReturn(mockDto);
//when
List<VendorDTO> vendorDTOList = vendorService.getAllVendors();
//then
assertEquals(3, vendorDTOList.size());
}
And the test should pass.

Have you tried to put #RunWith(MockitoJUnitRunner.class)/#ExtendsWith(MockitoExtension.class) over your test class?

Spring AOP: aspect is not executing in case of MethodConstraintViolationException

I have a bean annoteded with JSR 303 annotations. I also added Spring aspect (#Around) for handling MethodConstraintViolationException. My problem is: if I execute methods with correct parameters - my aspect works (is executed - breakpoints added), but when I run methods with incorrect parameters then MethodConstraintViolationException is thrown and my aspect is not executed.
package noname.exception;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.hibernate.validator.method.MethodConstraintViolationException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.Ordered;
import noname.service.exceptions.ValidationException;
import noname.utils.ValidationExceptionProcessor;
#Aspect
public class ExceptionAspect implements Ordered {
#Autowired
private ValidationExceptionProcessor processor;
#Pointcut(value = "execution(* noname.conversionstrategy.api.IDocumentConverter.*(..))")
public void aopDocumentConverterPointcut() {
}
#Pointcut(value = "execution(* noname.service.api.IMailMerger.*(..))")
public void aopMailMargeServicePointcut() {
}
#SuppressWarnings("deprecation")
#Around("aopDocumentConverterPointcut() || aopMailMargeServicePointcut()")
public Object exceptionsAspect(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
try {
return proceedingJoinPoint.proceed();
} catch ( Throwable e ) {
if (e instanceof MethodConstraintViolationException) {
ValidationException exp = processor.process((MethodConstraintViolationException) e);
throw exp;
} else {
throw e;
}
}
}
#Override
public int getOrder() {
return Ordered.HIGHEST_PRECEDENCE;
}
}
Intefaces (IMailMerger and IDocumentConverter) are similar:
package noname.conversionstrategy.api;
import java.util.List;
import javax.validation.constraints.NotNull;
import org.springframework.validation.annotation.Validated;
import noname.service.domain.DocumentActionInput;
import noname.service.domain.DocumentActionResult;
import noname.validator.ValidActionInput;
#Validated
public interface IDocumentConverter {
DocumentActionResult convertDocument(#NotNull(message = "DocumentActionInput must be provided") #ValidActionInput DocumentActionInput document);
List<DocumentActionResult> convertDocuments(#NotNull(message = "DocumentActionInput must be provided") #ValidActionInput List<DocumentActionInput> documents);
}
I suppose spring execute first bean validation (it is probably executed with aspect too (?) ). If this validation throws MethodConstraintViolationException then my aspect is not executed, because spring aop doesn't support catching exceptions from anoother aspect (need confirmation).
I also created test with proxy (everything with my aspect looks fine):
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = {"classpath:applicationContextTest.xml"})
public class ExceptionAspectSpringTest {
#Autowired
private IDocumentConverter documentConverter;
#Autowired
private ExceptionAspect exceptionAspect;
private IDocumentConverter proxy;
#Before
public void setUp() {
AspectJProxyFactory aspectJProxyFactory = new AspectJProxyFactory(documentConverter);
aspectJProxyFactory.addInterface(IDocumentConverter.class);
aspectJProxyFactory.addAspect(exceptionAspect);
proxy = aspectJProxyFactory.getProxy();
}
#Test( expected = ValidationException.class )
public void shouldThownValidationException() {
DocumentActionInput document = new DocumentActionInput();
proxy.convertDocument(document);
}
}
Any help appreciated

How to configure JUnit rules to apply to specific test

Is it possible to have a Junit rule only apply to specific tests? If so, how do I do that?
The code below exemplifies what I want to do: each time I have #Rule, I want the method below that to have the specific rule that has been annotated to run with it. I only want that rule to run with the corresponding test. I don't want anything other tests to be affected by the rule.
In this case, when I run these tests, I see that one of the tests the EmptyFileCheck, gives a File DNE does not exist, but I have used a separate annotation for that function, so I had thought that it would run with a different context, supplying the Empty, but instead DNE is till being used.
import static java.lang.System.in;
import static java.lang.System.setIn;
import static org.junit.Assert.fail;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.io.PrintStream;
import java.nio.channels.Pipe;
import static org.hamcrest.core.AllOf.allOf;
import org.hamcrest.Matcher;
import org.hamcrest.core.AllOf;
import static org.hamcrest.Matchers.*;
import org.hamcrest.text.StringContains;
import org.hamcrest.text.StringEndsWith;
import org.hamcrest.text.StringStartsWith;
import org.jmock.Expectations;
import org.jmock.Mockery;
import org.jmock.lib.legacy.ClassImposteriser;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.contrib.java.lang.system.TextFromStandardInputStream;
import org.junit.runner.RunWith;
public class UnitTests {
private Mockery context = new Mockery() {{
setImposteriser(ClassImposteriser.INSTANCE);
}};
private main mn;
private InputStream oldIn;
private PrintStream oldOut;
private InputStream mockIn;
private InputStreamReader mockinputStream;
private PrintStream mockOut;
private BufferedReader reader;
private Expectations exp;
#Before
public void setMinimalMockingExpectations() throws IOException {
exp = new Expectations() {{ }};
mn = context.mock(main.class);
mockinputStream = context.mock(InputStreamReader.class);
oldIn = System.in;
oldOut = System.out;
mockIn = context.mock(InputStream.class);
mockOut = context.mock(PrintStream.class);
System.setOut(mockOut);
}
public void configureExpectations(boolean fileOrInput, boolean verbosity) {
exp.one(mockOut).println("Do you want to process standard (I)nput, or a (F)ile? I/F");
if (fileOrInput) { //it's a file
exp.one(mockOut).println("Enter filename: ");
} else { //it's not
}
}
#After
public void reset() {
System.setOut(oldOut);
}
#Rule
public final TextFromStandardInputStream FileNotFoundException
= new TextFromStandardInputStream("F\nDNE\n");
#Test(expected=FileNotFoundException.class)
public void EnsureFileCheckExists() throws IOException {
final String fileName = "DNE";
configureExpectations(true, false);
exp.one(mn).checkFile(fileName);
context.checking(exp);
mn.main(null);
}
#Rule
public final TextFromStandardInputStream FileReadAccessDenied
= new TextFromStandardInputStream("F\nUnderPriviledged\n");:w
#Test(expected=FileNotFoundException.class)
public void FileReadAccessDenied() throws java.io.FileNotFoundException {
final String fileName = "UnderPriviledged";
configureExpectations(true, false);
//exp.oneOf(mn).checkFile(with()); TODO: fix ME!
context.checking(exp);
mn.main(null);
}
#Rule
public final TextFromStandardInputStream EmptyFileCheck
= new TextFromStandardInputStream("F\nEmpty\n");
#Test
public void EmptyFileCheck() throws java.io.FileNotFoundException {
final String fileName = "Empty";
configureExpectations(true, false);
exp.one(mn).checkFile(fileName);
context.checking(exp);
mn.main(null);
}
}

You could have a setter in your Rule which is the first thing that gets called in the rule. Something like this, from ExpectedException:
// These tests all pass.
public static class HasExpectedException {
#Rule
public ExpectedException thrown= ExpectedException.none();
#Test
public void throwsNothing() {
// no exception expected, none thrown: passes.
}
#Test
public void throwsNullPointerException() {
thrown.expect(NullPointerException.class);
throw new NullPointerException();
}
#Test
public void throwsNullPointerExceptionWithMessage() {
thrown.expect(NullPointerException.class);
thrown.expectMessage("happened?");
thrown.expectMessage(startsWith("What"));
throw new NullPointerException("What happened?");
}
}

Any reason not to just take the code out of the #rule annotation and move it to the start of the test body?

Detect Failure or Error of Junit Test in #After method

Is there a way in JUnit to detect within an #After annotated method if there was a test failure or error in the test case?
One ugly solution would be something like that:
boolean withoutFailure = false;
#Test
void test() {
...
asserts...
withoutFailure = true;
}
#After
public void tearDown() {
if(!withoutFailuere) {
this.dontReuseTestenvironmentForNextTest();
}
}
This is ugly because one need to take care of the "infrastructure" (withoutFailure flag) in the test code.
I hope that there is something where I can get the test status in the #After method!?

If you are lucky enough to be using JUnit 4.9 or later, TestWatcher will do exactly what you want.
Share and Enjoy!

I extend dsaff's answer to solve the problem that a TestRule can not execute some code snipped between the execution of the test-method and the after-method. So with a simple MethodRule one can not use this rule to provide a success flag that is use in the #After annotated methods.
My idea is a hack! Anyway, it is to use a TestRule (extends TestWatcher). A TestRule will get knowledge about failed or success of a test. My TestRule will then scan the class for all Methods annotated with my new AfterHack annotations and invoke that methods with a success flag.
AfterHack annotation
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
#Retention(RUNTIME)
#Target(METHOD)
public #interface AfterHack {}
AfterHackRule
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import org.junit.rules.TestWatcher;
import org.junit.runner.Description;
public class AfterHackRule extends TestWatcher {
private Object testClassInstance;
public AfterHackRule(final Object testClassInstance) {
this.testClassInstance = testClassInstance;
}
protected void succeeded(Description description) {
invokeAfterHackMethods(true);
}
protected void failed(Throwable e, Description description) {
invokeAfterHackMethods(false);
}
public void invokeAfterHackMethods(boolean successFlag) {
for (Method afterHackMethod :
this.getAfterHackMethods(this.testClassInstance.getClass())) {
try {
afterHackMethod.invoke(this.testClassInstance, successFlag);
} catch (IllegalAccessException | IllegalArgumentException
| InvocationTargetException e) {
throw new RuntimeException("error while invoking afterHackMethod "
+ afterHackMethod);
}
}
}
private List<Method> getAfterHackMethods(Class<?> testClass) {
List<Method> results = new ArrayList<>();
for (Method method : testClass.getMethods()) {
if (method.isAnnotationPresent(AfterHack.class)) {
results.add(method);
}
}
return results;
}
}
Usage:
public class DemoTest {
#Rule
public AfterHackRule afterHackRule = new AfterHackRule(this);
#AfterHack
public void after(boolean success) {
System.out.println("afterHack:" + success);
}
#Test
public void demofails() {
Assert.fail();
}
#Test
public void demoSucceeds() {}
}
BTW:
1) Hopefully there is a better solution in Junit5
2) The better way is to use the TestWatcher Rule instead of the #Before and #After Method at all (that is the way I read dsaff's answer)
#see

I don't know any easy or elegant way to detect the failure of a Junit test in an #After method.
If it is possible to use a TestRule instead of an #After method, one possibility to do it is using two chained TestRules, using a TestWatcher as the inner rule.
Example:
package org.example;
import static org.junit.Assert.fail;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExternalResource;
import org.junit.rules.RuleChain;
import org.junit.rules.TestRule;
import org.junit.rules.TestWatcher;
import org.junit.runner.Description;
public class ExampleTest {
private String name = "";
private boolean failed;
#Rule
public TestRule afterWithFailedInformation = RuleChain
.outerRule(new ExternalResource(){
#Override
protected void after() {
System.out.println("Test "+name+" "+(failed?"failed":"finished")+".");
}
})
.around(new TestWatcher(){
#Override
protected void finished(Description description) {
name = description.getDisplayName();
}
#Override
protected void failed(Throwable e, Description description) {
failed = true;
}
})
;
#Test
public void testSomething(){
fail();
}
#Test
public void testSomethingElse(){
}
}