Mockito Unit test lombok.extern.slf4j #Slf4j annotation log? - unit-testing

I have a method that calls a method called "burn" inside that throws a data exception, and if so, then it is caught in a try/catch block and logs to a logger. The class is using the annotation #Slf4j however, and lombok.extern.slf4j:
#Slf4j
public class MyClass {
private void myMethod(Type parameter) throws Exception {
try {
dataGateway.burn(id);
}
catch {
log.error("Failed to burn({})",id);
}
}
I have already mocked the datagateway and have it throwing an exception when burn is called, I know the exception is caught but how do I use verify to assert the logger was called with .error??
DateGateway dBMock = mock(DateGateway.class);
when(dBMock.burn(anyString())).thenReturn(new DataException("exception"));

I found a nice solution to this problem here: https://www.jvt.me/posts/2019/09/22/testing-slf4j-logs/
The solution was to add a log appender to the class you want to test and then just read what has been logged from that appender.
Here is a generic method to add and return an appender for a specific class:
private ListAppender<ILoggingEvent> getListAppenderForClass(Class clazz) {
Logger logger = (Logger) LoggerFactory.getLogger(clazz);
ListAppender<ILoggingEvent> loggingEventListAppender = new ListAppender<>();
loggingEventListAppender.start();
logger.addAppender(loggingEventListAppender);
return loggingEventListAppender;
}
In your case you could then use this appender like this in your test to verify that your specific log row was invoked:
final ListAppender<ILoggingEvent> listAppenderForClass = getListAppenderForClass(CardApi.class);
org.assertj.core.api.Assertions.assertThat(listAppenderForClass.list)
.extracting(ILoggingEvent::getFormattedMessage)
.anyMatch((Predicate<String>) s -> s.startsWith("Failed to burn"));

You can try library: https://www.simplify4u.org/slf4j-mock/
It is also work with lombok annotation.
With slf4j-mock you don't need special code for preparing logger mock.

Related

Mockito cannot mock java.lang.reflect.Method

please help.
I have a class to test against with junit test.
Class
#Override
public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
...
final Object toReturn = method.invoke(this.impl, objects);
...
}
Test class I have
#Test
public void test() throws Throwable {
try {
APIController apiController = new APIController(paramMock1, new Gson());
Method method = apiController.getClass().getMethod("ping");
methodMock = Mockito.mock(method.getClass()); **---> Fail**
Mockito.doNothing().when(methodMock).invoke(Mockito.anyObject(), Mockito.any());
proxy.invoke(new Object(), method, new Object[]{});
} catch (Exception ex) {
Assert.assertTrue(ex instanceof NullPointerException);
}
}
The error message is
Cannot mock/spy class java.lang.reflect.Method
Mockito cannot mock/spy following:
- final classes
- anonymous classes
- primitive types`
I did some research and added
#RunWith(PowerMockRunner.class)
on top of test class, but error still comes.
How can I test with a mocked of this Method? Thank you.
PowerMock and Mockito are different mocking frameworks, so just adding the #RunWith(PowerMockRunner.class) annotation would not solve your problem. Powermock could be useful (I'm not very familiar with it, so not sure here), but you would need to rewrite the test to use it instead of mockito.
But from what I see you most likely don't need to mock the Method class — for your task it would be sufficient to just mock the object on which you want to mock the method. Something like this:
APIController apiController = mock(APIController.class);
doNothing().when(apiController).ping(...);
// pass the mocked apiController to your proxy;
// test that proxy.invoke calls the ping method

Spring boot mocking static methods with PowerMock in Integration test

I'm writing integration test on a RestController in SpringBoot.
Normally I would run with SpringRunner.class, but when it comes to Mock a static method I need to use PowerMock.
The strange fact is that when I run the single tests, they individually pass (but returns error messages), when I try to run the entire test class, no test passes and it returns the same error message.
#RunWith(PowerMockRunner.class)
#PrepareForTest({JwtUtils.class})
//#PowerMockRunnerDelegate(SpringRunner.class) THIS DOESN'T WORK!!!
#SpringBootTest(classes = SpringBootJwtApplication.class)
public class RestAccessIntegrationTest {
#Autowired #InjectMocks
RestController restController;
#Mock
HttpServletRequest request;
#Test
public void operationsPerAccountWhenSuccessfulTest(){
mockStatic(JwtUtils.class);
when(JwtUtils.myMethod(request)).thenReturn("blabla");
String expected = ... ;
String actual = restController.getOperations();
assertEquals(actual, expected);
}
}
If I run the test or the entire class I get an error of this type:
Exception in thread "main" java.lang.NoSuchMethodError: org.powermock.core.MockRepository.addAfterMethodRunner(Ljava/lang/Runnable;)at org.powermock.api.mockito.internal.mockcreation.MockCreator.mock(MockCreator.java:50)
If I uncomment #PowerMockRunnerDelegate(SpringRunner.class) there it comes this other error:
Exception in thread "main" java.lang.NoClassDefFoundError: org/powermock/core/testlisteners/GlobalNotificationBuildSupport$Callback
at org.powermock.modules.junit4.internal.impl.DelegatingPowerMockRunner.run(DelegatingPowerMockRunner.java:139)
In the when method, try using any(HttpServletRequest.class) instead of the request mock object. Also use MockHttpServletRequest instead of mocking HttpServletRequest. This should work,
#RunWith(PowerMockRunner.class)
#PrepareForTest(JwtUtils.class)
#PowerMockIgnore( {"javax.management.*"})
public class RestAccessIntegrationTest {
#InjectMocks
private RestController restController;
private MockHttpServletRequest request;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
request = new MockHttpServletRequest();
RequestContextHolder.setRequestAttributes(
new ServletRequestAttributes(request));
}
#Test
public void operationsPerAccountWhenSuccessfulTest() {
mockStatic(JwtUtils.class);
when(JwtUtils.myMethod(any(HttpServletRequest.class)))
.thenReturn("blabla");
String expected = ... ;
// does your getOperations take HttpServletRequest
// as parameter, then controller.getOperations(request);
String actual = restController.getOperations();
assertEquals(actual, expected);
}
}
It was due to incompatibility in library version of PowerMock and Mockito. I suggest to check the compatibility version table provided by PowerMock team or to switch to JMockit to mock static and private methods.

How to Mock DataSource Dependency Injection Despite Being Accessible via Static Method

I'm using Mockito, DBUnit and HSQLDB to unit test my database code. I'm also writing integration tests of course.
I'm having trouble understanding how to inject a mocked DataSource into the system under test (class I'm testing). The DataSource is used for connection pooling, and therefore other classes can call a static method in the same class in order to retrieve an instance of this DataSource. This means that the DataSource is not injected into any constructors, anywhere, and so my tests don't have any constructors to inject the mocked DataSource into.
I'm getting around this by altering the logic of my real code to check if a private variable is null, and if so then use the injected DataSource (bad design since it's only needed for tests), otherwise it calls the static method to retrieve the connection pool's source (better design).
How do I inject a mocked DataSource into a class that doesn't have a constructor set up to accept it, because it can instead just call the static method to retrieve the dependency?
Class to Test
public DBConnection(DBSource dbSource) { // <--- Constructor only required for test purposes :(
this.dbSource = dbSource;
}
public final void createCompsDB() {
Connection conn = null;
Statement statement = null;
try {
if(dbSource==null){
conn = DBSource.getInstance().getConnection();
}else{
conn = dbSource.getConnection(); /** Likely bad design, since dbSource is only NOT null for tests, so that you can inject the mocked datasource :( */
}
statement = conn.createStatement();
statement.executeUpdate("CREATE DATABASE placesdb");
System.out.println("Database created...");
} catch (SQLException e) {
// ...
}
} finally {
// Close Resources...
}
}
}
Test Class -- Test Passes
public class DBConnectionTest {
final Statement statement = mock(Statement.class);
final Connection connection = mock(Connection.class);
final DBSource dataSource = mock(DBSource.class);
#Before
public void setUp() throws SQLException, IOException, PropertyVetoException {
when(dataSource.getConnection()).thenReturn(connection);
when(connection.createStatement()).thenReturn(statement);
}
#Test
public void testCreateCompDBIfNotAlready() throws Exception {
DBConnection dbConnection = new DBConnection(localDB, dataSource); /** This constructor is only needed for testing :( . How do I avoid it since all the classes I need to test don't require the dependency to be injected? */
dbConnection.createCompsDB();
verify(statement).executeUpdate("CREATE DATABASE PLACES");
}
}
DBSource.java
protected DBSource() throws IOException, SQLException, PropertyVetoException {
ds = new BasicDataSource();
ds.setDriverClassName("org.postgresql.Driver");
ds.setUsername("user");
ds.setPassword("pass");
ds.setUrl("jdbc:postgresql://localhost:5432/placesdb");
}
public static DBSource getInstance() { // <--- Static method means dependent classes don't need to accept injections
if (datasource == null) {
datasource = new DBSource();
return datasource;
} else {
return datasource;
}
}
public Connection getConnection() throws SQLException {
return this.ds.getConnection();
}
}
Mocking of the static class methods may be done with PowerMockito.
The test class should be something like this:
#RunWith(PowerMockRunner.class)
#PrepareForTest(DBSource.class)
public class DBConnectionTest {
#Mock
final Statement statement;
#Mock
final Connection connection;
#Mock
final DBSource dbsource;
#Before
public void setUp() throws SQLException, IOException, PropertyVetoException {
PowerMockito.mockStatic(DBSource.class);
when(DbSource.getInstance()).thenReturn(dbsource);
when(dbsource.getConnection()).thenReturn(connection);
when(connection.createStatement()).thenReturn(statement);
}
#Test
public void testCreateCompDBIfNotAlready() throws Exception {
DBConnection dbConnection = new DBConnection(localDB); // No test-only constructor anymore
dbConnection.createCompsDB();
verify(statement).executeUpdate("CREATE DATABASE PLACES");
}
}
You can read here more about mocking with PowerMock.

Eclipse Scout client unit tests with ScoutClientTestRunner

I am trying to create unit test with scout context and I can't find proper tutorial or example for it.
When I create test with ScoutClientTestRunner, I get error
java.lang.Exception: Client session class is not set. Either set the default client session using 'ScoutClientTestRunner.setDefaultClientSessionClass' or annotate your test class and/or method with 'ClientTest'
I try to set client session class like this :
#Before
public void setClassSession() throws Exception {
ScoutClientTestRunner.setDefaultClientSessionClass(ClientSession.class)
}
and
#BeforeClass
public void setClassSession() throws Exception {
ScoutClientTestRunner.setDefaultClientSessionClass(ClientSession.class);
}
I try to add #ClientTest to the class and to all methods but I still get same error.
How to set client session in tests if you use ScoutClientTestRunner ?
The ScoutClientTestRunner ensures that the JUnit tests are executed having all the Scout Context (OSGi and so on) available.
Your attempts with #Before or #BeforeClass are too late. You need to provide the Scout Context initialization parameters before that. As the exception message says, you have 2 possibilities:
(1) #ClientTest annotation
You can annotate test classes or methods with #ClientTest using the clientSessionClass parameter:
#RunWith(ScoutClientTestRunner.class)
#ClientTest(clientSessionClass = ClientSession.class)
public class DesktopFormTest {
#Test
public void test1() throws Exception {
//Do something requiring a scout context:
//for example instantiate a DesktopForm.
}
}
If necessary you can also do it at method level:
#RunWith(ScoutClientTestRunner.class)
public class DesktopFormTest {
#Test
#ClientTest(clientSessionClass = Client1Session.class)
public void test1() throws Exception {
//client session is an instance of Client1Session.
}
#Test
#ClientTest(clientSessionClass = Client2Session.class)
public void test2() throws Exception {
//client session is an instance of Client2Session.
}
}
(2) Defining a TestEnvironment
When the test is run (directly or using maven-tycho), a lookup for a fully qualified class org.eclipse.scout.testing.client.runner.CustomClientTestEnvironment is done.
The CustomClientTestEnvironment class should implement org.eclipse.scout.testing.client.runner.IClientTestEnvironment
The method setupGlobalEnvironment() is called once and can be used to define the default client session with ScoutClientTestRunner.setDefaultClientSessionClass(..). This method can also be used to register required services.
Here an example:
package org.eclipse.scout.testing.client.runner; // <= can not be changed.
// add imports
public class CustomClientTestEnvironment implements IClientTestEnvironment {
#Override
public void setupGlobalEnvironment() {
//Set client session:
ScoutClientTestRunner.setDefaultClientSessionClass(ClientSession.class);
}
#Override
public void setupInstanceEnvironment() {
}
}
Of course (1) and (2) are compatible. The second mechanism defines only the default and ClientSession configured with (1) will override the default.

How to unit test an interceptor?

I want to write some unit tests for an interceptor that intercepts the Loggable base class (which implements ILoggable).
The Loggable base class has no methods to call and it is used only to be initialized by the logging facility.
To my understanding I should:
Mock an ILoggable and an ILogger
Initialize the logging facility
Register my interceptor on it
Invoke some method of the mocked ILoggable
The problem is that my ILoggable interface has no methods to call and thus nothing will be intercepted.
What is the right way to act here?
Should I mock ILoggable manually and add a stub method to call?
Also, should I be mocking the container as well?
I am using Moq and NUnit.
EDIT:
Here's my interceptor implementation for reference:
public class LoggingWithDebugInterceptor : IInterceptor
{
#region IInterceptor Members
public void Intercept(IInvocation invocation)
{
var invocationLogMessage = new InvocationLogMessage(invocation);
ILoggable loggable = invocation.InvocationTarget as ILoggable;
if (loggable == null)
throw new InterceptionFailureException(invocation, string.Format("Class {0} does not implement ILoggable.", invocationLogMessage.InvocationSource));
loggable.Logger.DebugFormat("Method {0} called with arguments {1}", invocationLogMessage.InvokedMethod, invocationLogMessage.Arguments);
Stopwatch stopwatch = new Stopwatch();
try
{
stopwatch.Start();
invocation.Proceed();
stopwatch.Stop();
}
catch (Exception e)
{
loggable.Logger.ErrorFormat(e, "An exception occured in {0} while calling method {1} with arguments {2}", invocationLogMessage.InvocationSource, invocationLogMessage.InvokedMethod, invocationLogMessage.Arguments);
throw;
}
finally
{
loggable.Logger.DebugFormat("Method {0} returned with value {1} and took exactly {2} to run.", invocationLogMessage.InvokedMethod, invocation.ReturnValue, stopwatch.Elapsed);
}
}
#endregion IInterceptor Members
}
If it's just the interceptor that uses the Logger Property on your class than why have in there at all? You might just as well have it on the interceptor. (like Ayende explained in his post here).
Other than that - interceptor is just a class which interacts with an interface - everything highly testable.
I agree with Krzysztof, if you're looking to add Logging through AOP, the responsibility and implementation details about logging should be transparent to the caller. Thus it's something that the Interceptor can own. I'll try to outline how I would test this.
If I follow the question correctly, your ILoggable is really just a naming container to annotate the class so that the interceptor can determine if it should perform logging. It exposes a property that contains the Logger. (The downside to this is that the class still needs to configure the Logger.)
public interface ILoggable
{
ILogger { get; set; }
}
Testing the interceptor should be a straight-forward process. The only challenge I see that you've presented is how to manually construct the IInvocation input parameter so that it resembles runtime data. Rather than trying to reproduce this through mocks, etc, I would suggest you test it using classic State-based verification: create a proxy that uses your interceptor and verify that your log reflects what you expect.
This might seem like a bit more work, but it provides a really good example of how the interceptor works independently from other parts of your code-base. Other developers on your team benefit from this as they can reference this example as a learning tool.
public class TypeThatSupportsLogging : ILoggable
{
public ILogger { get; set; }
public virtual void MethodToIntercept()
{
}
public void MethodWithoutLogging()
{
}
}
public class TestLogger : ILogger
{
private StringBuilder _output;
public TestLogger()
{
_output = new StringBuilder();
}
public void DebugFormat(string message, params object[] args)
{
_output.AppendFormat(message, args);
}
public string Output
{
get { return _output.ToString(); }
}
}
[TestFixture]
public class LoggingWithDebugInterceptorTests
{
protected TypeThatSupportsLogging Input;
protected LoggingWithDebugInterceptor Subject;
protected ILogger Log;
[Setup]
public void Setup()
{
// create your interceptor
Subject = new LoggingWithDebugInterceptor();
// create your proxy
var generator = new Castle.DynamicProxy.ProxyGenerator();
Input = generator.CreateClassProxy<TypeThatSupportLogging>( Subject );
// setup the logger
Log = new TestLogger();
Input.Logger = Log;
}
[Test]
public void DemonstrateThatTheInterceptorLogsInformationAboutVirtualMethods()
{
// act
Input.MethodToIntercept();
// assert
StringAssert.Contains("MethodToIntercept", Log.Output);
}
[Test]
public void DemonstrateNonVirtualMethodsAreNotLogged()
{
// act
Input.MethodWithoutLogging();
// assert
Assert.AreEqual(String.Empty, Log.Output);
}
}
No methods? What are you testing?
Personally, this sounds like it goes too far. I realize that TDD and code coverage is dogma, but if you mock an interface with no methods and prove that the mocking framework does what you instructed it to do, what have you really proven?
There's another misdirection going on here: logging is the "hello world" of aspect oriented programming. Why aren't you doing logging in an interceptor/aspect? If you did it that way, there'd be no reason for all your classes to implement ILoggable; you could decorate them with logging capability declaratively. I think it's a less invasive design and a better use of interceptors.