We are using Junit to run our tests and inside of our business code we have an instance method of a service that access a static class that has state. If Junit runs sequentially for each method of a class by default, I mean with one single thread, if for each test method I set the needed static state, it would not be a problem, right?
In order to initialize this state of the static class, I am using static blocks instead of beforeClass because sometimes all test methods of a class have the same state for that static class. Is this ok or should I use #BeforeClass?
Thanks
Related
I am creating junit test cases for my project. I have the below code, where I would like to create a mock,
String propertyFilePath = System.getProperty("path.to.properties");
Resource propertyFile = new FileSystemResourceLoader().getResource(propertyFilePath);
Properties properties = PropertiesLoaderUtils.loadProperties(propertyFile);
I am using junit and mockito-core jar. I tried with below code,
System.setProperty("path.to.properties", "dummyPathToProperties"); //invalid Path
Properties properties = mock(Properties.class);
Resource propertyFile = new FileSystemResourceLoader().getResource("dummyPathToProperties");
when(PropertiesLoaderUtils.loadProperties(propertyFile)).thenReturn(properties);
With above code it throws error when mocking loadProperties method. How can I mock a spring static class and return my mock properties object ?
Any help will be really appreciated.
Mocking static methods requires you to go down the full nine yards and make use of PowerMock. The exact steps to mock static methods are outlined in their documentation for example.
In essence:
Use the #RunWith(PowerMockRunner.class) annotation at the class-level of the test case.
Use the #PrepareForTest(ClassThatContainsStaticMethod.class) annotation at the class-level of the test case.
Use PowerMock.mockStatic(ClassThatContainsStaticMethod.class) to mock all methods of this class.
Use PowerMock.replay(ClassThatContainsStaticMethod.class) to change the class to replay mode.
Use PowerMock.verify(ClassThatContainsStaticMethod.class) to change the class to verify mode.
But of course: consider not using PowerMock; by changing your code so that you don't have to mock the static call. But of course, it is kinda weird to add a wrapper around such a framework-provided static method.
I need to execute some code before the #Before method of each unit test is executed. The problem is that I also need to know which test (the name is sufficient) will be executed afterwards.
I can either use AspectJ or Java Agents with bytecode manipulation to achieve this. Also the solution should work for tests where there is no #Before annotation present.
Any ideas?
EDIT: I can't modify the unit tests themselves, as I'm developing a framework for executing tests of other projects
You might want to look into the TestName rule in JUnit:
http://junit.org/junit4/javadoc/4.12/org/junit/rules/TestName.html
About the ordering, a solution could be to define a super class for your tests and put a #Before in there, as #Before methods in super classes are run before those in sub classes.
If you want to write a Java agent and you are not bound to Javassist or AspectJ, have a look at Byte Buddy for doing so. You can add the code in the MyAdvice class to any method annotated with #Test given that the type name ends with Test (as an example) by:
public class MyAgent {
public static void premain(String arg, Instrumentation inst) {
new AgentBuilder.Default()
.type(nameEndsWith("Test"))
.transform((type, cl, builder) -> builder.visit(Advice
.to(MyAdvice.class)
.on(isAnnotatedWith(Test.class)))
.installOn(instrumentation);
}
}
class MyAdvice {
#Advice.OnMethodEnter
static void enter() {
System.out.println("foo");
}
}
Just bundle the above code to a Javaagent with the proper manifest code and register it before running. If you are running on a JDK, you can also attach the agent programmatically using the byte-buddy-agent project.
I have this line which is interferring in a unit test:
OtherClass.staticMethodThatWillErrorIfCalled().isAvailable();
If it wasn't static I could just mock OtherClass and then do this:
Mockito.doReturn(null).when(mockedOtherClass).staticMethodThatWillErrorIfCalled();
Mockito.doReturn(true).when(mockedOtherClass).isGuiMode();
and the fact that it will error if called makes my attempts at using powermockito futile.
I'm not sure how I can do this. All I want to do is skip over this line (it's an if check) and continue on as if it had returned true. What is the best way to do this?
I would require more info to give a more specific answer but this is what I am thinking...
First tell PowerMockito that you will be mocking a static method in OtherClass.
#RunWith(PowerMockRunner.class)
#PrepareForTest(OtherClass.class)
These are class level annotations that go on your unit testing class.
Then mock what to do when that method is called.
PowerMockito.mockStatic(OtherClass.class);
Mockito.when(OtherClass.isAvailable()).thenReturn(Boolean.TRUE);
Do this in your #Before method on your unit testing.
I use Guice to instantiate a VocabularyAPI object for one of my unit tests unitTest1(). However, for another test (unitTest2()), I simply use mockito's #Mock annotation to mock an instance of the same class - VocabularyAPI.
I noticed that when I only run unitTest2() - mockito's mock setting for my VocabularyAPI is configured correctly. However, when I run the entire test suite (both unitTest1() and unitTest2()), both the tests are instantiated with the settings from the injector.
How can I limit the scope of the injected object to only inside the test that it is being injected? I want to be able to use the injected object in unitTest1() and mocked object for unitTest2().
Any problems in using local variables?
In unitTest1():
VocabularyAPI vocabularyAPI = // inject (I'm not familiar with Guice)
In unitTest2():
VocabularyAPI vocabularyAPI = Mockito.mock(VocabularyAPI.class);
Does anyone know what is the scope of this annotation? For example, if I have multiple JUnit test classes that run sequentially in the same VM, and the first test uses #SuppressStaticInitializationFor, does that suppress the static initialization for all the subsequent test classes, too? I ask because I am under the impression that static state persists for the life of the JVM.
The scope is per classloader. Once you've used #SuppressStaticInitializationFor it'll affect the class in all other tests. You can however #SuppressStaticInitializationFor at the method level instead and that way it won't affect other tests.
you can use #SuppressStaticInitializationFor annotation at the class-level or at the method-level of the test where you want it to be suppressed.
#RunWith(PowerMockRunner.class)
#SuppressStaticInitializationFor("com.main.java.CassName")
public class TestClassName extends PowerMockTestCase {
//code
#SuppressStaticInitializationFor("com.main.java.AnotherClassName")
public void testMethod() {
//code
}
}
This way you can control which method should suppress static initializers(constructors) and for which class.