I am using Mockito services to test the Exception that could be thrown in MyFinalClass2 and be caught in MyAbstractClass as the concrete method makes a call to the getValue method in MyFinalClass2. This method returns an interface (MyInterfaceClass) object.
I asked a question earlier in Mocking Chained calls in Concrete Class Mockito and thankfully, the solution provided works when calling the getObject method found in MyFinalClass . Therefore, test1 works!
However, this time I have another final class (MyFinalClass2) which is not #Autowired, and is called after a call to a method in MyFinalClass. An Object of type MyFinalClass2 is return from the first call to method in MyFinalClass. When manually throwing a MyException2 in test2 , it does not get recognized and therefore causes an AssertionFailure in Test2 .
Also please note, the below line of code returns NULL as it has not yet been implemented. Which is the reason why I am returning in Test2 a new instance of MyFinalClass2 when this method is called.
MyFinalClass2 myFinalClass2 = getObject(strName);
Please see below code.
public abstract class MyAbstractClass{
#Autowired
private MyFinalClass myFinalClass;
//concrete method
protected MyInterfaceClass myConcreteMethod(String strName, String str)
{
try{
//returns null as it has not yet been implemented
MyFinalClass2 myFinalClass2 = getObject(strName);
MyInterfaceClass b = getValue(myFinalClass2,str);
return b;
} catch(MyException e){
LOGGER.log("ERROR THROWN" + e);
} catch(MyException2 e){
LOGGER.log("ERROR THROWN" + e);
}
}
public MyFinalClass2 getObject(String strName){
return myFinalClass.getObject(strName);
}
public MyInterfaceClass getValue(MyFinalClass2 myFinalClass2, String
str){
return myFinalClass2.getValue(str);
}
}
public final class MyFinalClass {
public MyFinalClass2 getObject(String strName) throws MyException{
**** HAS NOT YET BEEN IMPLEMENTED ****
return null;
}
}
public final class MyFinalClass2 {
public MyInterfaceClass getValue(String str) throws MyException2{
**** HAS NOT YET BEEN IMPLEMENTED ****
return null;
}
}
public interface MyInterfaceClass {
**** HAS NOT YET BEEN IMPLEMENTED BY ANY CLASS ****
void getStuff();
}
#ContextConfiguration(locations = "classpath:applicationContext-test.xml")
#RunWith(PowerMockRunner.class)
public class MyAbstractClassTest {
public static class ExampleConcreteClass extends MyAbstractClass{
}
#InjectMocks
#Spy
ExampleConcreteClass exampleConcreteClass;
#Before
public void setUp(){
MockitoAnnotations.initMocks(this);
}
//THIS WORKS --- TEST 1
#Test
public void testIfExceptionOneIsThrown(){
try{
Mockito.when(exampleConcreteClass).getObject(name).
thenThrow(new MyException());
exampleConcreteClass.myConcreteMethod();
Assert.fail();
}catch(MyException e){
Assert.assertTrue(Boolean.TRUE);
}
}
//This test DOES NOT work --- TEST 2
#Test
public void testIfExceptionTwoIsThrown(){
try{
MyFinalClass2 myFinClass2 = new MyFinalClass2();
String strName = "name";
String str = "str";
Mockito.when(exampleConcreteClass).getValue(myFinClass2,str).
thenThrow(new MyException2());
Mockito.when(exampleConcreteClass).getObject(strName).
thenReturn(myFinClass2);
exampleConcreteClass.myConcreteMethod();
Assert.fail();
}catch(MyException e){
Assert.fail();
}catch(MyException2 e){
Assert.assertTrue(Boolean.TRUE);
}
}
}
Please help. Greatly Appreciated!
First of all, I am sorry to say so, but if you need to think that hard about testing, it's normally a sure sign that the code is bad. Anway, you don't need PowerMock there, since Mockito 2 is able to mock final classes already (you have to opt-in for that, though).
Also your test doesn't make any sense at all, since your exampleConcreteClass.myConcreteMethod() cannot throw a MyException2, because...
} catch(MyException2 e){
LOGGER.log("ERROR THROWN" + e);
}
...thus the MyException2 will never leave the scope of the method, but be transformed into a log message there and then be discarded. It will not leave the method, thus trying to assert it will not work. You would have something like throw e; there, too:
} catch(MyException2 e){
LOGGER.log("ERROR THROWN" + e);
throw e; // re-throw e, otherwise it ends here
}
Also, just as a hint, what you are trying to do there can be more easily done by simple writing...
#Test(expected=MyException2.class)
public void testIfExceptionTwoIsThrown() throws MyException, MyException2 {
...this way, you can remove all the try-catch stuff from your test method, since JUnit will automatically fail the test if no MyException2 is thrown. Alternatively, if you want to have more control, you can even have a look at JUnit's ExpectedException rule, which is a little bit more powerful and versatile than just the expected parameter (but that one should be enough for this case).
But of course, nothing changes the fact that, as long as your method catches your MyException2, it will not leave said method, so testing for it will not help.
Related
I have the below code where I am lazy loading the instance creation of my class.
public class MyTest {
private static MyTest test = null;
private UniApp uniApp;
private MyTest(){
try{
uniApp = new UniApp("test","test123");
}
catch(Exception e){
e.printStackTrace();
logger.error("Exception " +e+ "occured while creating instance of uniApp");
}
}
public static MyTest getInstance(){
if (test == null){
synchronized(MyTest.class){
if (test == null){
test = new MyTest();
}
}
}
return test;
}
In the constructor, I am creating an instance of UniApp that requires passing userid, password in its own constructor. If lets say I pass a wrong userid, password of the uniApp object, uniApp doesn't get created. Here is what I need -
I am invoking the getInstance method in a different class -
MyTest test=MyTest.getInstance();
And here, I want to add condition if failure of creation of uniApp happens, do blah. How do I do that?
In general, if I am trying to invoke a method that throws an exception in class A in class B, and put a condition in B - if the method in class A throws exception, do this.
How can I achieve this? Let me know if my question is confusing. I can edit it :)
Throwing an exception from your private constructor would be ok (reference This SO question, or do some quick Googling). In your case, you are catching the exception thrown from new UniApp() and not passing it along - you can very easily pass that exception up the foodchain into your getInstance() method and then to whomever calls that singleton.
For instance, using your code:
private MyTest() throws UniAppException { // Better if you declare _which_ exception UniApp throws!
// If you want your own code to log what happens, keep the try/catch but rethrow it
try{
uniApp = new UniApp("test","test123");
}
catch(UniAppException e) {
e.printStackTrace();
logger.error("Exception " +e+ "occured while creating instance of uniApp");
throw e;
}
}
public static MyTest getInstance() throws UniAppException {
if (test == null) {
synchronized(MyTest.class) {
if (test == null) {
test = new MyTest();
}
}
}
return test;
}
To create your "if" condition to test whether the getInstance() method works or not, surround your call to getInstance() with a try/catch block:
...
MyTest myTest;
try {
myTest = MyTest.getInstance();
// do stuff with an instantiated myTest
catch (UniAppException e) {
// do stuff to handle e when myTest will be null
}
...
Since you haven't shown what actually calls MyTest.getInstance() I can't tell you what else to do besides that.
I have the following scenario:
public class ClassA {
public void methodA(){
try {
int result=methodB();
} catch (IOException e) {
//Some code here
}
}
private int methodB() throws IOException{
//Some code here
return 1;
}
}
I want to cover the catch block of the public method methodA() in my test. I don't want to change the visibility of the private method. Is there any way to achieve partial mock of private method using EasyMock? Or is there any way to change the behaviour of private method in my Junit class to throw exception without using mocking?
Thanks in advance.
You cannot do this with Easymock alone, you can do this with a combination of EasyMock and Powermock. Then you mock the return value of the private method.
To test the catch block, you must tell EasyMock to throw an exception when calling methodB.
From the docs:
For specifying exceptions (more exactly: Throwables) to be thrown, the object returned
by expectLastCall() and expect(T value) provides the method andThrow(Throwable throwable).
The method has to be called in record state after the call to the Mock Object for which
it specifies the Throwable to be thrown.
Example:
expectLastCall().andThrow(new IOException("Now to test catch block..."));
I have the below interface
public interface Interface1 {
Object Execute(String commandToExecute) throws Exception;
}
which then I 'm trying to mock so I can test the behaviour of the class that will call it:
Interface1 interfaceMocked = mock(Interface1.class);
when(interfaceMocked.Execute(anyString())).thenThrow(new Exception());
Interface2 objectToTest = new ClassOfInterface2(interfaceMocked);
retrievePrintersMetaData.Retrieve();
But the compiler tells me that there is an unhandled exception.
The definition of the Retrieve method is:
public List<SomeClass> Retrieve() {
try {
interface1Object.Execute("");
}
catch (Exception exception) {
return new ArrayList<SomeClass>();
}
}
The mockito documentation only shows uses of RuntimeException, and I have not seen anything on similar on StackOverflow.
I'm using Java 1.7u25 and mockito 1.9.5
Assuming your test method doesn't declare that it throws Exception, the compiler's absolutely right. This line:
when(interfaceMocked.Execute(anyString())).thenThrow(new Exception());
... calls Execute on an instance of Interface1. That can throw Exception, so you either need to catch it or declare that your method throws it.
I would personally recommend just declaring that the test method throws Exception. Nothing else will care about that declaration, and you really don't want to catch it.
You can use doAnswer method of Mockito to thrown checked exceptions, like this
Mockito.doAnswer(
invocation -> {
throw new Exception("It's not bad, it's good");
})
.when(interfaceMocked)
.Execute(org.mockito.ArgumentMatchers.anyString());
You shouldn't be having a problem if your method returns something and throws your error. Now if your method returns void you won't be able to throw an error.
Now the real thing is that you're not testing that your interface throws an exception, instead what you're testing what happens when an exception is thrown within this method.
public List<SomeClass> Retrieve() {
try {
interface1Object.Execute("");
}
catch (Exception exception) {
return handleException(exception);
}
}
protected List<SomeClass> handleException(Exception exception) {
return new ArrayList<SomeClass>();
}
Then you just call your handleException method and make sure it returns the correct thing. If you need to make sure that your interface is throwing an exception, then that is a different test for your interface class.
It might seem sucky that you are having to make a method for a single line but that's what happens sometimes if you want testable code.
Good time!
I need to substitute the class' private void method with a mock implementation, and can't to figure out how to do this. I've tried to use such a construction:
Test test = PowerMock.createPartialMock(Test.class, "setId");
PowerMock.expectPrivate(test , "setId", EasyMock.anyLong()).andAnswer(
new IAnswer<Void>() {
#Override
public Void answer() throws Throwable {
return null;
}
});
PowerMock.replay(test);
but the internal PowerMock's class called WhiteBox invokes my "setId" method which is wrong for my task. Could someone, please, suggest, how to avoid the method invokation and possibly to replace the method body with a custom one?
Finally. I've got the solution.
The problem was I missed the following annotations:
#RunWith(PowerMockRunner.class)
#PrepareForTest(Test.class)
Anyway, it seems rather confusing that to make the PowerMock working I need to add some annotations. If that wasn't a legacy code I'd prefer Mockito.
Not quite sure that I get the question.
But for me code below works perfect and just string "Invoked!" is getting printed
and if I remove test.setS(33L); test will fail with exception:
#RunWith(PowerMockRunner.class)
#PrepareForTest(MainTest.Test2.class)
public class MainTest {
#Test
public void testName() throws Exception {
Test2 test = PowerMock.createPartialMock(Test2.class, "setS");
PowerMock.expectPrivate(test , "setS", EasyMock.anyLong()).andAnswer(
new IAnswer<Void>() {
#Override
public Void answer() throws Throwable {
System.out.println("Invoked!");
return null;
}
}).atLeastOnce();
PowerMock.replay(test);
test.setS(33L);
PowerMock.verify(test);
}
class Test2 {
long s;
private long getS() {
return s;
}
private void setS(long s) {
this.s = s;
System.out.println("Not this!");
}
}
}
I'm using EasyMock to create mock objects for JUnit testing in Java. I create a mock object and pass it to another thread where it expects methods to be called. In the other thread, the calls are enclosed in a try/catch(Throwable) block, so when an unexpected call occurs on the mock and it thus throws AssertionError, that error is caught by the catch block and treated. So, even though an unexpected call occurred, the test passes.
In order to have the test fail as expected, I would like to delay all verification of calls to the EasyMock.verify(mock) call made in the test-runner thread at the end. Is this possible and how?
I'm not sure about how to do this with EasyMock, but this behavior is possible with Mockito because verification assertions can be specified at the end of the test.
The correct solution I'd guess is to stop catching Throwable. Doing so catches all Errors as you're finding, which can be quite dangerous... are you absolutely positively 100% sure you need to catch Throwable? Why?
(If it turns out you do, you could catch AssertionError specifically and rethrow it. But that's ugly!)
Try using nice mocks:
http://easymock.org/EasyMock2_5_2_Documentation.html
"Nice Mocks
On a Mock Object returned by createMock() the default behavior for all methods is to throw an AssertionError for all unexpected method calls. If you would like a "nice" Mock Object that by default allows all method calls and returns appropriate empty values (0, null or false), use createNiceMock() instead. "
Default values will be returned for unexpected calls instead of throwing AssertionError, but you can still verify them with the verify() method (in which case the AssertionErrors will be thrown)
As #deterb suggested, it's possible with Mockito but you have to know the method name or you have to set expectations for every method. Here is an example:
The mocked interface:
public interface MyInterface {
void allowedMethod();
void disallowedMethod();
}
The user class which catches AssertionError:
public class UserClass {
public UserClass() {
}
public static void throwableCatcher(final MyInterface myInterface) {
try {
myInterface.allowedMethod();
myInterface.disallowedMethod();
} catch (final Throwable t) {
System.out.println("Catched throwable: " + t.getMessage());
}
}
}
And the Mockito test:
#Test
public void testMockito() throws Exception {
final MyInterface myInterface = mock(MyInterface.class);
UserClass.throwableCatcher(myInterface);
verify(myInterface, never()).disallowedMethod(); // fails here
}
The same is possible with EasyMock but it needs some work:
#Test
public void testEasyMock() throws Exception {
final AtomicBoolean called = new AtomicBoolean();
final MyInterface myInterface = createMock(MyInterface.class);
myInterface.allowedMethod();
myInterface.disallowedMethod();
final IAnswer<? extends Object> answer = new IAnswer<Object>() {
#Override
public Object answer() throws Throwable {
System.out.println("answer");
called.set(true);
throw new AssertionError("should not call");
}
};
expectLastCall().andAnswer(answer).anyTimes();
replay(myInterface);
UserClass.throwableCatcher(myInterface);
verify(myInterface);
assertFalse("called", called.get()); // fails here
}
Unfortunately you also have to know the method names here and you have to define expectations like myInterface.disallowedMethod() and expectLastCall().andAnswer(answer).anyTimes().
Another possibility is creating a proxy with the Proxy class (with a custom InvocationHandler) and using it as a mock object. It definitely needs more work but it could be the most customizable solution.
Finally don't forget that it's also possible to create a custom implementation with or without delegation to the EasyMock mock object. Here is one with delegation:
public class MockedMyInterface implements MyInterface {
private final MyInterface delegate;
private final AtomicBoolean called = new AtomicBoolean();
public MockedMyInterface(final MyInterface delegate) {
this.delegate = delegate;
}
#Override
public void allowedMethod() {
delegate.allowedMethod();
}
#Override
public void disallowedMethod() {
called.set(true);
throw new AssertionError("should not call");
}
public boolean isCalled() {
return called.get();
}
}
And the test for it:
#Test
public void testEasyMockWithCustomClass() throws Exception {
final MyInterface myInterface = createMock(MyInterface.class);
myInterface.allowedMethod();
final MockedMyInterface mockedMyInterface =
new MockedMyInterface(myInterface);
replay(myInterface);
UserClass.throwableCatcher(mockedMyInterface);
verify(myInterface);
assertFalse("called", mockedMyInterface.isCalled()); // fails here
}