I need to mock a static method. I know of two tools to help do this: PowerMockito and JMockit, both of which require usage of the #RunWith annotation. However, I've already used #RunWith for SpringRunner to set up some #Autowired dependencies, and it seems you can't use #RunWith twice.
I see that PowerMockito has a PowerMockRunnerDelegate, which looks promising. But for various reasons, I'm stuck using JMockit for now. Is there a JMockit equivalent for this?
I essentially need to mock a static method and set up #Autowired dependencies for my test at the same time.
It looks like I can circumvent the need to use any specialized static mocking tool by wrapping the static method call.
The latest version of jmockit (1.49) does not utilize the #RunWith annotation. Instead, it has you setup a javaagent as a vmarg. There's full documentation on the jmockit site: https://jmockit.github.io/tutorial/Introduction.html#runningTests. I'd definitely encourage you to use JMockIt rather than the EasyMock+PowerMock combo, JMockIt is self-contained and handles statics naturally.
Related
I have a problem getting Spring Boot 2.0.5 to work nicely with Kotlintest 3.1.10.
I made a test project illustrating the problem I have.
The project is a Spring Boot 2 application
with two entities, ShoppingOrder and OrderLine (to be totally unimaginative).
There is also a test case ShoppingOrderSpec which just tests the mapping by storing and retrieving the Order.
The testcase is configured like this:
#ExtendWith(SpringExtension::class)
#Transactional
#SpringBootTest
class ShoppingOrderSpec : WordSpec() {
override fun listeners() = listOf(SpringListener)
The test case is using the SpringExtension
by Spring to hook into the JUnit 5 engine. It also uses the SpringListener and Wordspec from Kotlintest to structure the tests
and do the assertions.
The SpringListener correctly autowires the dependencies, but somehow the transaction is not being created.
Running the testcase gives the following stack-trace:
2018-10-12 10:54:14.329 INFO 59374 --- [intest-engine-0] com.example.demo.ShoppingOrderSpec : Started ShoppingOrderSpec in 4.478 seconds (JVM running for 7.421)
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.example.demo.ShoppingOrder.lines, could not initialize proxy - no Session
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:582)
...
at com.example.demo.ShoppingOrderSpec$1$1.invoke(ShoppingOrderSpec.kt:35)
at com.example.demo.ShoppingOrderSpec$1$1.invoke(ShoppingOrderSpec.kt:19)
So, somehow the org.springframework.transaction.annotation.Transactional annotation does not seem to work,
as removing the annotation, just gives the same response.
Anyone any ideas how to get the #Transactional being applied and respected?
You can't use JUnit Jupiter extensions with KotlinTest as they are different engines. Junit Jupiter is an implementation on top of Junit Platform, like KotlinTest is, but anything written specifically for Jupiter won't work with KotlinTest. Anything written for Junit Platform should work however.
Unfortunately, the naming choices by the JUnit team are poor imo, and so people think JUnit Jupiter is the same thing as JUnit Platform.
Anyway, those
#ExtendWith(SpringExtension::class)
#Transactional
#SpringBootTest
extensions are not going to mean anything to KotlinTest, anymore than they would for Spek or whatever. ExtendWith is a Jupiter specific annotation that tells it to use the SpringExtension class. The KotlinTest equivilent is SpringListener which you've already wired in.
I'm not sure if #SpringBootTest will be picked up or not by Spring. Support may need to be added for that depending on what it does.
Finally #Transactional works by creating proxies on the methods, but since in more advanced testing frameworks like KotlinTest, the test containers are not methods, but just arbitrary functions, it won't be able to intercept.
I think in this case, you might need to create a proper method and annotate that, or try using the AnnotationSpec rather than StringSpec or whatever other spec base class you are using, which uses actual methods that you could annotate.
I want to implement my own custom annotations, that is why I am looking for Spring annotations' implementation. Which code executes behind the screen when we use an annotation?
Definition of an annotation is pretty simple. You can find definition of #Autowired annotation here:
https://github.com/spring-projects/spring-framework/blob/master/spring-beans/src/main/java/org/springframework/beans/factory/annotation/Autowired.java
If you're interested in its processing, you can clone spring-framework repository and search for its usage in the code of Spring.
If you want to implement your own custom annotation processor, I'd recommend to search for simpler examples than Spring and #Autowired.
I'm also planning to play around with annotation processors and I collected a few links related to this topic. Maybe you'll find them useful.
Java related:
https://github.com/bozaro/example-annotation-processor
https://github.com/eugenp/tutorials/tree/master/annotations
http://www.baeldung.com/java-annotation-processing-builder
https://www.gesellix.net/post/providedcompile-and-compile-dependencies-with-gradle/
http://programmaticallyspeaking.com/playing-with-java-annotation-processing.html
https://github.com/Jimdo/gradle-apt-plugin
http://mrhaki.blogspot.com/2016/03/gradle-goodness-enable-compiler.html
https://github.com/sockeqwe/annotationprocessing101
http://hannesdorfmann.com/annotation-processing/annotationprocessing101
https://www.javacodegeeks.com/2015/09/java-annotation-processors.html
and bonuses
Android related:
https://medium.com/#iammert/annotation-processing-dont-repeat-yourself-generate-your-code-8425e60c6657
https://stablekernel.com/the-10-step-guide-to-annotation-processing-in-android-studio/
https://medium.com/#emmasuzuki/annotation-processor-101-your-first-custom-annotation-a3db9ae48046
http://blog.jensdriller.com/android-annotation-processing-setup-using-gradle/
Kotlin related:
https://blog.jetbrains.com/kotlin/2015/06/better-annotation-processing-supporting-stubs-in-kapt/
What's the recommended way to run a spring boot test where only the one subject under test is configured in the context.
If I annotate the test with
#RunWith(SpringRunner.class)
#SpringBootTest(properties = "spring.profiles.active=test")
#ContextConfiguration(classes = MyTestBean.class)
Then it seems to work - the test passes, the context starts quickly and seems to only contain the bean that I want. However, this seems like an incorrect use of the #ContextConfiguration(classes = MyTestBean.class) annotation. If I understand correctly the class that I reference is supposed to be a Configuration class, not a regular spring service bean or component for example.
Is that right? Or is this indeed a valid way to achieve this goal? I know there are more complex examples like org.springframework.boot.test.autoconfigure.json.JsonTest which use #TypeExcludeFilters(JsonExcludeFilter.class) to control the context - but this seems overkill for my use case. I just want a context with my one bean.
Clarification
I know that I can just construct the one bean I am testing as a POJO without a spring context test and remove the three annotations above. But in my precise use case I am actually reliant on some of the configuration applied to the context by settings in the application-test.properties file - which is why I've made this a Spring Boot test with a profile set. From my perspective this isn't a plain unit test of a single class in isolation of the spring context configuration - the test is reliant on certain configuration being applied (which is currently provided by the spring boot app properties). I can indeed just test the components as a POJO by creating a new instance outside of a spring context, I'm using constructor injection making the providing of necessary dependencies simple but the test does rely on things like the log level (the test actually makes assertions on certain logs being produced) which requires that the log level is set correctly (which is currently being done via logging.level.com.example=DEBUG in a properties file which sets up the spring context).
For starters, reading the documentation first (e.g., the JavaDoc linked below in this answer) is a recommend best practice since it already answers your question.
If I understand correctly the class that I reference is supposed to be
a Configuration class, not a regular spring service bean or
component for example.
Is that right?
No, that's not completely correct.
Classes provided to #ContextConfiguration are typically #Configuration classes, but that is not required.
Here is an excerpt from the JavaDoc for #ContextConfiguration:
Annotated Classes
The term annotated class can refer to any of the following.
A class annotated with #Configuration
A component (i.e., a class annotated with #Component, #Service, #Repository, etc.)
A JSR-330 compliant class that is annotated with javax.inject annotations
Any other class that contains #Bean-methods
Thus you can pass any "annotated class" to #ContextConfiguration.
Or is this indeed a valid way to achieve this goal?
It is in fact a valid way to achieve that goal; however, it is also a bit unusual to load an ApplicationContext that contains a single user bean.
Regards,
Sam (author of the Spring TestContext Framework)
It is definitely a reasonable and normal thing to only test a single class in a unit test.
There is no problem including just one single bean in your test context. Really, a #Configuration is (typically) just a collection of beans. You could hypothetically create a #Configuration class just with MyTestBean, but that would really be unnecessary, as you can accomplish doing the same thing listing your contextual beans with #ContextConfiguration#classes.
However, I do want to point out that for only testing a single bean in a true unit test, best practice ideally leans towards setting up the bean via the constructor and testing the class that way. This is a key reason why the Spring guys recommend using constructor vs. property injection. See the section entitled Constructor-based or setter-based DI of this article, Oliver Gierke's comment (i.e. head of Spring Data project), and google for more information. This is probably the reason you're getting a weird feeling about setting up the context for the one bean!
You can also use ApplicationContextRunner to create your context using a test configuration of your choice (even with one bean if you like, but as other people have already mentioned for one bean it's more reasonable to use the constructor the classical way without using any spring magic).
What I like this way of testing is the fact that test run very fast since you don't load all the context. This method is best used when the tested bean doesn't have any Autowired dependencies otherwise it's more convenient to use #SpringBootTest.
Below is an example that illustrates the way you can use it to achieve your goal:
class MyTest {
#Test
void test_configuration_should_contains_my_bean() {
new ApplicationContextRunner()
.withUserConfiguration(TestConfiguration.class)
.run(context -> {
assertThat(context.getBean(MyTestBean.class)).isNotNull();
});
}
#Configuraiton
public static class TestConfiguration {
#Bean
public MyTestBean myTestBean(){
new MyTestBean();
}
}
}
I've been looking for an answer for a while, but no luck so far, thus I'm coming here for some words of wisdom.
I've created an aspect using #Aspect annotation, because I need to #Autowire some singleton dependencies I've decided to annotate this aspect class with #Component and let the Spring to do the magic. It works, however ...
I'm fairly familiar with AOP concept, what's weaving and different flavors of it (cglib vs aspectj) but it's not fully intuitive to me how it works under the hood.
#Component means a given class will be a singleton within a given context, #Aspect means that the content of an aspect class will be somehow weaved into the target class during runtime/compilation - and this target class is not a singleton but prototype for instance. So what I'm ending up with at the end?
Spring AOP does not do compile-time-weaving and does not modify the code of the advised target. Instead it works with proxies that are weaved around the joinpoints. That is why Spring AOP aspects and be used as (singleton) components, have their fields autowired, etc., like any other Spring Proxy.
It is also the reason why Spring AOP aspects only work for public method executions, not field accesses and the like.
The documentation is quite well written and goes into as much (or as little) detail as one might like:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/aop.html
The book AspectJ in Action's section 2.5 is on the internal working of the weaving step, it is only 2 page but gets the point across well.
Luckily the section is available here.
This is for posterity.
I've got an application which uses JAXRS to map Restlet resources using annotations. However, the only entry point I have is essentially defining a list of resource classes in the application configuration. These classes are instantiated by Restlet or JAXRS, so I have no way to put them in my ApplicationContext. Is there a way to have Spring scan the classpath and autowire new instances as necessary? I've already tried using something like below:
#Autowired
private SessionFactory sessionFactory;
Unfortunately, it doesn't really work. Is there a way to do what I'm talking about here?
You can use AspectJ to dependency inject your beans that are created out of your control, or if you create objects using new. You can read more on Springs documentation: http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/aop.html#aop-using-aspectj
Essentially what you will do is add #Configurable annotation to the class that you want to be target of injection. You also have to enable it in Spring by having in your Spring xml. Lastly you have to decide between compile time weaving or runtime weaving. Again you can get help from spring documentation.
Loadtime weaving: http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/aop.html#aop-aj-ltw
If you use maven you can check this Stackoverflow question for setting up compile time AspectJ: Why doesn't AspectJ compile-time weaving of Spring's #Configurable work?
ApplicationContext.getAutowireCapableBeanFactory().autowireBean(object) will inject all dependencies into the object.