Aside from that it may suffer from the same issue as the @Test way, depending on where you place the expectation. We can test expected exceptions using JUnit 5 assertThrows assertion. Mockito 2 . Annotate your test method with: I'm using mockito in a junit test. I know you're using NUnit, but there's a xUnit issue that describes why you don't need to assert it. In this article, we look at how to test exceptions using JUnit5. Powermock junit5 and mockito2.x not working RunnerTestSuiteChunker not found, Mockito Tests Pass individually but fail as part of a suite, IntelliJ Idea not resolving Mockito and JUnit dependencies with Maven. 2. At this point it should be clear how we're going to handle these exceptions. Mockito - Verifying Method Calls in Mockito 3 |Mockito - Verifying Mock Behavior in Java JUnit Tests KK JavaTutorials 1.6K views 1 year ago JUnit 4 with IntelliJ: Exceptions, Ignore, .. Here's an example of how you can use these methods to mock and assert a thrown exception: import static org.mockito.Mockito. Can I use a vintage derailleur adapter claw on a modern derailleur, Applications of super-mathematics to non-super mathematics. Assertions assertThrows () API. Moreover, JUnit tooling does have some pitfalls. verifyZeroInteractions() method behavior is same as verifyNoMoreInteractions() method. You get paid; we donate to tech nonprofits. will catch-exception still print the stacktrace? Below is a complete example showing how to test exception as well as exception message. Busque trabalhos relacionados a Illegal reflective access by org mockito internal util reflection accessibilitychanger ou contrate no maior mercado de freelancers do mundo com mais de 22 de trabalhos. How to throw an exception in Java Mockito? (Java.Util.Logging), How to Set Auto-Scrolling of Jtextarea in Java Gui, How to Draw in JPAnel? Each catch block includes the exception type and can contain additional statements needed to handle that exception type. >. I am a passionate Java developer with years of experience, and a love for sharing my knowledge through talks and my personal blog. It might be convenient for some, but if you follow Behaviour Driven Development (BDD) or Arrange Act Assert (AAA) principles the ExpectedException rule won't fit in those writing style. Mockito How to mock and assert a thrown exception? However, if you want to be explicit, you can do: You can always use the .not method, which will be valid if your initial condition is false. method after you verif, Return the contained value, if present, otherwise throw an exception to be Catch an exception with assertThrows JUnit5 includes an Assertion that you can use to verify thrown exceptions. But these ways are not so elegant and don't mix well readability wise with other tools. A sample of this could be the IllegalArgumentException which is caught with the @Test(expected = IllegalArgumentException.class) annotation. Wed like to help. You can use when and thenThrow to mocke Exeption1 from someFunc, then f1() should catch exception and throw Exception2. If we want to verify that only one method is being called, then we can use only() with verify method. As always, the full source code can be found over on GitHub. For example there is an object method that throws exception if you call it the second time. If we want to test exception message, then we will have to use ExpectedException rule. Yes, any execution thrown from a test method would cause a test to fail. How do I fit an e-hub motor axle that is too big? All rights reserved. What factors changed the Ukrainians' belief in the possibility of a full-scale invasion between Dec 2021 and Feb 2022? Introduction To test a program implies adding value to it. Catch throwables If you want to catch both throwables and exceptions have a look at the catch-throwable packages in javadoc. Here's an example of how you might use this in a test case: In this example, we set up a mock object of type MyClass and configure it to throw a RuntimeException when its someMethod method is called. This keeps your testing code well structured and allows you to quickly run through the architecture to find where things go wrong, instead of having to hop all over the place. as in example? For checking the cause of the exception, I use: expectedException.expectCause(Mockito.sameInstance(expectedException)) or expectedException.expectCause(Mockito.instanceOf(MyException.class)) and a few others that come in handy. Should I include the MIT licence of a library which I use from a CDN? How to derive the state of a qubit after a partial measurement? Was Galileo expecting to see so many stars? privacy statement. It's the test method's responsibility to catch any exceptions that occur and write them to the console, so that they don't interfere with the running The full source code for the examples is available over on GitHub. In the following Mockito provides the capability to a mock to throw exceptions, so exception handling can be tested. Hence you can click and find the place where Mockito was misused. But even though the exception might be thrown in the next test, the exception message contains a navigable stack trace element with location of the defect. It is possible to write yourself a do it yourself try-catch block or use the JUnit tools (@Test(expected = ) or the @Rule ExpectedException JUnit rule feature). ordering of its keys, "This should only appear in the logs. Taking all into account if you don't want to use the catch-exception tool, I will recommend the old good way of the try-catch block, at least up to the JDK7. Using mockito, you can make the exception happen. happen. If this method fails (e.g. expect-run-verify Mockito . One should not test to show that the program works rather that it does not work. And even if it was based on Mockito 2 in the current version, this would require to declare a global mock maker (inline-mock-maker), something that may not what you want, as this mock maker has different drawbacks that the regular mock maker. The ExpectedException rule is also an attempt to fix the previous caveats, but it feels a bit awkward to use as it uses an expectation style, EasyMock users know very well this style. Does Cast a Spell make you a spellcaster? Login to the mysql database server, verify the database is running or shutdown. Note that in JUnit 4, we needed to use @Test (expected = NullPointerException.class) syntax. Stubbing AssertJ has been updated to provide a nice fluent API to assert exceptional behaviour. Is something's right to be free more important than the best interest for its own species according to deontology? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. This means that if we pass Exception as the expected exception type, any exception thrown will make the assertion succeed since Exception is the super-type for all exceptions. "archive already exists: the-archive-path", testOnBodyPartReceivedWithResumableListenerThrowsException(). Why does Jesus turn to the Father to forgive in Luke 23:34? is there any way we can mock throw exception for void methods? The high level overview of all the articles on the site. Using mockito, you can make the exception happen. Why is processing a sorted array faster than processing an unsorted array? If an uncaught or unexpected exception is thrown, the test will fail. If any method call is deleted by mistake, then verify method will throw an error. throw an exception. To clarify further. You can verify the type of the parameter being passed in several different ways: verify { ErrorReportManager.logHandledException(ofType(JSONException::class)) } verify { ErrorReportManager.logHandledException(match { it is JSONException }) } Can the Spiritual Weapon spell be used as cover? : an exception is thrown) then you know something went wrong and you can start digging. We can test exact number of times, at least once, at least, at most number of invocation times for a mocked method. How i can stop call a method void with mockito? This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. And to "mock" an exception with mockito, use, Updated answer for 06/19/2015 (if you're using java 8), Using assertj-core-3.0.0 + Java 8 Lambdas, Reference: http://blog.codeleak.pl/2015/04/junit-testing-exceptions-with-java-8.html. to your account, converting from mockito to mockk Verify that the correct methods of our mock objects were invoked. These issues won't apply once the library supports lambdas. In this example there is a basic method called getUserById() which will return a user and there is a total of 3 unit of works. I. If we want to make sure a method is called but we dont care about the argument, then we can use ArgumentMatchers with verify method. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. rev2023.3.1.43269. ", shouldNotInitializeServerIfSettingIsTurnedOff(), when(systemEnvironment.getAgentStatusEnabled()).thenReturn(, NativeIndexPopulator failOnDropNativeIndexPopulator(). exception you expect and an Executable. Testing means raising the reliability and quality of the program. Manning Publications Co. To comment go to liveBook 15. Launching the CI/CD and R Collectives and community editing features for How do you assert that a certain exception is thrown in JUnit tests? How do you assert that a certain exception is thrown in JUnit tests? RecyclableBufferedInputStream(wrapped, byteArrayPool); shouldGiveAClearErrorIfTheArchiveAlreadyExists(). We can use JUnit 4 @Test annotation expected attribute to define the expected exception thrown by the test method. Critical issues have been reported with the following SDK versions: com.google.android.gms:play-services-safetynet:17.0.0, Flutter Dart - get localized country name from country code, navigatorState is null when using pushNamed Navigation onGenerateRoutes of GetMaterialPage, Android Sdk manager not found- Flutter doctor error, Flutter Laravel Push Notification without using any third party like(firebase,onesignal..etc), How to change the color of ElevatedButton when entering text in TextField. MAPSMART >. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 1. https://javadoc.io/doc/org.mockito/mockito-core/5.1.1/package-list Close How to test anonymous methods with JUnit or Mockito? @pringi Thanks, I see that the question concerned both mocking an exception and catching it. This issue has been automatically marked as stale because it has not had recent activity. Connect and share knowledge within a single location that is structured and easy to search. GitHub Instantly share code, notes, and snippets. This JUnit assertion method returns the thrown exception, so we can use it to assert exception message too. Learn more. I'm using mockito in a junit test. It depends on the JUnit version and what assert libraries you use. All Rights Reserved. @pringi Thanks, I see that the question concerned both mocking an exception and catching it. The open-source game engine youve been waiting for: Godot (Ep. Here is a simple example showing how to assert exception in JUnit 5. With the JDK8, lambdas enter the test scene, and they have proved to be an interesting way to assert exceptional behaviour. You can explore MongoDB through their free forever cluster - Atlas. To verify that the exception did happen, assert a false condition within the try block after the statement that throws the exception. Also as the expectation is placed around in the method, depending on how the tested code is written then the wrong part of the test code can throw the exception, leading to false-positive test and I'm not sure that PMD, findbugs or Sonar will give hints on such code. We will cover how to verify an exception, verify a specific In addition, the use of ExpectedException is error-prone when used with other rules like TestWatcher because the order of rules is important in that case. DigitalOcean makes it simple to launch in the cloud and scale up as you grow whether youre running one virtual machine or ten thousand. DigitalOcean makes it simple to launch in the cloud and scale up as you grow whether youre running one virtual machine or ten thousand. You can use this It is done using the verify () method. Use Mockito's doThrow and then catch the desired exception to assert it was thrown later. Remember As Mockito is still not updated this library cannot work with final classes or final methods. Then in our test, we're asserting that the code that attempts to parse an Integer value will result in a NumberFormatException with the message For input string. (Don't forget to add a fail() assertion before the catch block). Author cases that verify no exception is thrown. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Mockito alone is not the best solution for handling exceptions, use Mockito with Catch-Exception If you want to test the exception message as well you can use JUnit's ExpectedException with Mockito: to assert . Java (JVM) Memory Model - Memory Management in Java, Simple and reliable cloud website hosting, New! Take a look at the following code snippet. import org.junit.Test; public class ArithmaticTest { public String message = Saurabh; JUnitMessage junitMessage = new JUnitMessage(message); @Test(expected = ArithmeticException.class) public void testJUnitMessage(){ System.out.println("Junit Message is printing "); junitMessage.printMessage(); } @Test public void testJUnitHiMessage(){ message=Hi! + message; System.out.println("Junit Message is printing "); assertEquals(message, junitMessage.printMessage()); } } In the code above, JUnitMessage is showing an error, can you tell me why it is not working. A new exception instance will be created for each method invocation. 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. Executable interface. Such a method call can look like this: existingUserById_ShouldReturn_UserObject. Or, as defined in The art of Unit Testing, 2nd Edition by Roy Osherove, page 11: A unit test is an automated piece of code that invokes the unit of work being tested, and then checks some assumptions about a single end result of that unit. Example using @test (expected) Ok, but why would you want to verify the method called on the mocked object when youre the one that wrote the test-cases and know youve indeed called the methods that you want. This method can be used after all the verify methods to make sure that all the interactions are verified. created by the provided s, A component is an object having a graphical representation that can be displayed And you can use any assertion library like Hamcrest or AssertJ. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. doSomething () ). Why Is PNG file with Drop Shadow in Flutter Web App Grainy? Sign up for Infrastructure as a Newsletter. 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. Mockito + Catch-Exception + Assertj full sample, eu.codearte.catch-exception:catch-exception:2.0, http://blog.codeleak.pl/2015/04/junit-testing-exceptions-with-java-8.html, static.javadoc.io/org.mockito/mockito-core/2.23.4/org/mockito/. The List interface does not provide for a checked Exception to be thrown from the get (int index) method and that is why Mockito is failing. For "Visual Studio Team Test" it appears you apply the ExpectedException attribute to the test's method. Would the reflected sun's radiation melt ice in LEO? If you have a few years of experience in the Java ecosystem and you'd like to share that with the community, have a look at our Contribution Guidelines. mariuszs / MyTest.java Last active 3 days ago Star 9 Fork 1 Code Revisions 4 Stars 9 Forks 1 Embed Download ZIP Mockito + Catch Exception + AssertJ - BDD Style! If the test needs to check additional things on the exception like the cause or the message (good exception messages are really important, having a precise exception type may not be enough). The description of the third step is actually a bit misleading, because often we end up verifying that the correc Petri Kainulainen on Aug 3, 2018 bohsen commented on Aug 10, 2018 verify (view).hideProgressDialog () implicitly means the same as verify (view, times (1)).hideProgressDialog (). How does the NLT translate in Romans 8:2? Mockito - Verifying Behavior Previous Page Next Page Mockito can ensure whether a mock method is being called with reequired arguments or not. You don't have to do anything special, just run the code being tested. Mockito How to mock and assert a thrown exception. Mockito.doThrow (Showing top 20 results out of 4,194) Refine search Stubber.when Test.<init> Mockito.verify Mockito.mock Response.Status.getStatusCode ResponseSpecification.when RestAssured.given org.mockito Mockito doThrow Why must a product of symmetric random variables be symmetric? Thanks for contributing an answer to Stack Overflow! - Exception handling when calling a method JythonNullpointer - Nullpointer Exception when calling a method from Jython setMod - Get an exception when calling the setMod() method InvalidUseOfMatchersException - Wierd mockito . How to Get Just the Parent Directory Name of a Specific File, How to Capture Global Key Presses in Java, Can't Cast to to Unspecific Nested Type with Generics, Loading Raw 64-Byte Long Ecdsa Public Key in Java, Performance of Stringtokenizer Class VS. String.Split Method in Java, How to Set Up Java Logging Using a Properties File? Junit/Mockito - wait for method execution. Invalid: java.lang.Exception: Cannot process at com.logicbig.example.ProcessorTest.processTest (ProcessorTest.java:13) 4./at least x / never . Mockito.doThrow How to use doThrow method in org.mockito.Mockito Best Java code snippets using org.mockito. Premium CPU-Optimized Droplets are now available. By adding another test (nonExistingUserById_ShouldThrow_IllegalArgumentException) that uses the faulty input and expects an exception you can see whether your method does what it is supposed to do with wrong input. 2023 DigitalOcean, LLC. assertThrows () requires two arguments, Class <T> and Executable, assertThrows () can also take an optional third argument of either String or Supplier<String . Wed like to help. What are examples of software that may be seriously affected by a time jump? This JUnit assertion method returns the thrown exception, so we can use it to assert exception message too. And you need to test to test that it does throw exception during the second method call, not the first one. ( dumper ).dump( any(), any(), any(), any() ); CommandFailed commandFailed = assertThrows( CommandFailed. How would I do this in mockito and verify that I get Exception2 after forcing Exception 1 to be thrown? ArtifactPluginInfoBuilder(extension).pluginInfoFor(descriptor); Parsing JSON documents to java classes using gson. Working on improving health and education, reducing inequality, and spurring economic growth? When using JUnit 4, we can simply use the expected attribute of the @Test annotation to declare that we expect an exception to be thrown anywhere in the annotated test method. If you want to test if a particular Exception is not thrown in a condition where other exceptions could be thrown, try this: You don't have to assert if the method doesn't throw. // Call the method and catch the exception. Already on GitHub? Just test your functionality: if an exception is thrown the test will automatically fail. Testing is a costly activity. When you work with valid input you're setting the implicit expectancy that whatever test you write, will work. EDIT: It seems the project is brewing a Java 8 Lambdas support. Mockito How to mock and assert a thrown exception? Thanks for learning with the DigitalOcean Community. Working on improving health and education, reducing inequality, and spurring economic growth? Java (JVM) Memory Model - Memory Management in Java, Simple and reliable cloud website hosting, New! Is email scraping still a thing for spammers. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. //stubbing using . Thats all for a quick roundup on testing expected exceptions in JUnit 5 and JUnit 4. It's verify(moc, Use doAnswer() when you want to stub a void method with generic Answer. We can test expected exceptions using JUnit 5 assertThrows assertion. verify(mock, times(2)).someMethod("some arg"); Creates a spy of the real object. Was Galileo expecting to see so many stars? Raw MyTest.java import com.googlecode.catchexception.MyException; import org.junit.Test; By splitting this into two method that each do one thing, you will have much clearer tests and a much better overview of where things go wrong. It's trustworthy, readable, and maintainable. You can also see what methods are called, so why use verify? Shouldgiveaclearerrorifthearchivealreadyexists ( ) ).thenReturn (, NativeIndexPopulator < GenericKey, NativeIndexValue > failOnDropNativeIndexPopulator ). Nice fluent mockito verify exception thrown to assert it should be clear how we 're going to handle exceptions! We 're going to handle these exceptions JUnit 4 @ test ( =... Such a method void with mockito the thrown exception 'm using mockito, you agree to our terms service. Our mock objects were invoked an uncaught or unexpected exception is thrown ) you... Exception as well as exception message a passionate Java developer with years of,. These ways are not so elegant and do n't forget to add fail!, http: //blog.codeleak.pl/2015/04/junit-testing-exceptions-with-java-8.html, static.javadoc.io/org.mockito/mockito-core/2.23.4/org/mockito/ all for a quick roundup on testing expected exceptions using JUnit 5 right. Rss feed, copy and paste this URL into your RSS reader you need to test exceptions JUnit5. Flutter Web App Grainy mistake, then we will have to do anything special, just run the being! Team test '' it appears you apply the ExpectedException attribute to define the expected exception thrown by the scene. Catch throwables if you call it the second method call, not the first one stub a void method:... A complete example showing how to Set Auto-Scrolling of Jtextarea in Java simple. This article, we needed to use doThrow method in org.mockito.Mockito best Java code snippets org.mockito... Why you do n't need to assert exceptional behaviour do this in mockito and verify that I get Exception2 forcing... Paste this URL into your RSS reader then f1 ( ) expected attribute to define the expected thrown... Call can look like this: existingUserById_ShouldReturn_UserObject examples of software that may be seriously by. Method invocation, depending on where you place the expectation Luke 23:34 ExpectedException rule use it to assert it thrown... Pringi Thanks, I see that the question concerned both mocking an exception is in... Game engine youve been waiting for: Godot ( Ep all for a free account. Place where mockito was misused we want to verify that the program works rather that it may from! Passionate Java developer with years of experience, and a love for sharing my knowledge through talks and my blog! Mock throw exception during the second method call is deleted by mistake, f1... Moc, use doAnswer ( ) with verify method within a single location that is structured and to! Extension ).pluginInfoFor ( descriptor ) ; Creates a spy of the program issues wo n't apply the! This JUnit assertion method returns the thrown exception, you can start.. Rather that it does throw exception during the second time will throw an error with! Want to verify that I get Exception2 after forcing exception 1 to be free more important than the interest... Issue that describes why you do n't need to assert exception message you do n't to. Point it should be clear how we 're going to handle that exception type and contain! For example there is an object method that throws the exception did happen, a... You know something went wrong and you need to test exceptions using JUnit assertThrows... Annotate your test method would cause a test method to define the expected exception thrown by the will... The question concerned both mocking an exception is thrown, the test automatically! Have to use ExpectedException rule ) should catch exception and throw Exception2 would I do this in mockito verify! Exception if you call it the second time been updated to provide a nice API. These ways are not so elegant and do n't have to use doThrow method in org.mockito.Mockito best Java snippets... Be clear how we 're going to handle that exception type a spy the! Factors changed the Ukrainians ' belief in the cloud and scale up you... Species according to deontology question concerned both mocking an exception is thrown in JUnit tests if want! My knowledge through talks and my personal blog Java.Util.Logging ), how to derive the of... App Grainy with valid input you 're using NUnit, but there 's a issue!, any execution thrown from a test to fail void methods a nice fluent API to assert exception too. Point it should be clear how we 're going to handle that type... Value to it, you can start digging assert a thrown exception needed to use rule! And exceptions have a look at the catch-throwable packages in javadoc, privacy policy and cookie policy that the. ; Parsing JSON documents to Java classes using gson of software that may be seriously affected by a jump! The project is brewing a Java 8 lambdas support Dec 2021 and Feb?... Important than the best interest for its own species according to deontology database is running or.. Libraries you use ) annotation the Ukrainians ' belief in the cloud and up. Can I use a vintage derailleur adapter claw on a modern derailleur, Applications of to... X / never mistake, then we will have to do anything special, just run the code being.. Call can look like this: existingUserById_ShouldReturn_UserObject what assert libraries you use (,! Yes, any execution thrown from a CDN as you grow whether youre running one virtual or. Ukrainians ' belief in the following mockito provides the capability to a mock to throw exceptions, so we test. Catch both throwables and exceptions have a look at the catch-throwable packages in javadoc there any way we use! Expected attribute to the test will fail methods to make sure that the! Exception as well as exception message too features for how do you assert a... A New exception instance will be created for each method invocation, Applications of super-mathematics non-super! An uncaught or unexpected exception is thrown ) then you know something went wrong you. Education, reducing inequality, and snippets only ( ) method for void methods returns mockito verify exception thrown thrown.. Is too big super-mathematics to non-super mathematics use doThrow method in org.mockito.Mockito best Java code snippets using.! Modern derailleur, Applications of super-mathematics to non-super mathematics when you work with valid you. I 'm using mockito, you can make the exception happen clicking your... Reducing inequality, and snippets vintage derailleur adapter claw on a modern derailleur Applications... You write, will work their free forever cluster - Atlas MIT licence of a library I. Capability to a mock to throw exceptions, so we can use it! ) ; shouldGiveAClearErrorIfTheArchiveAlreadyExists ( ) as mockito is still not updated this library can not work valid! Through their free forever cluster - Atlas supports lambdas block after the that. Assert a false condition within the try block after the statement that throws exception you! Use ExpectedException rule with reequired arguments or not when you want to catch both throwables and exceptions a! Do I fit an e-hub motor axle that is too big JUnit test recyclablebufferedinputstream ( wrapped, byteArrayPool ) shouldGiveAClearErrorIfTheArchiveAlreadyExists... Exception during the second time for void methods the place where mockito was.... A fail ( ) with verify method will throw an error nice API! Sample of this could be the IllegalArgumentException which is caught with the,... Anonymous methods with JUnit or mockito a mock method is being called, so why verify! Set Auto-Scrolling of Jtextarea in Java, simple and reliable cloud website hosting New. It should be clear how we 're going to handle these exceptions void method with generic Answer the on! A vintage derailleur adapter claw on a modern derailleur, Applications of super-mathematics to non-super.! Than the best interest for its own species according to deontology exceptional behaviour work! Why you do n't forget to add a fail ( ) when you want to verify the. A library which I use from a CDN you write, will work you 're setting the implicit expectancy whatever! Article, we mockito verify exception thrown at the catch-throwable packages in javadoc not updated this library can not at... Should be clear how we 're going to handle these exceptions http //blog.codeleak.pl/2015/04/junit-testing-exceptions-with-java-8.html! 'Re setting the implicit expectancy that whatever test you write, will work health and education reducing! Simple and reliable cloud website hosting, New library which I use a vintage derailleur adapter claw a. 'S radiation melt ice in LEO and share knowledge within a single location is... Why you do n't mix well readability wise with other tools launching CI/CD. Previous Page Next Page mockito can ensure whether a mock method is being called with reequired arguments or not stub... Is running or shutdown to assert exceptional behaviour can click and find the place where mockito was misused can... You agree to our terms of service, privacy policy and cookie policy as. With valid input you 're using NUnit, but there 's a xUnit issue that describes why you n't... Sample of this could be the IllegalArgumentException which is caught with the JDK8, lambdas enter the will. For a quick roundup on testing expected exceptions using JUnit 5 handling can be after... On improving health and education, reducing inequality, and spurring economic growth not process at (... And reliable cloud website hosting, New have proved to be an interesting to. How do I fit an e-hub motor axle that is structured and easy to search there 's xUnit... There is an object method that throws the exception happen or shutdown between Dec and! A sample of this could be the IllegalArgumentException which is caught with the @ annotation! That the program mocking an exception is thrown in JUnit 5 assertThrows.!