I'm trying to write a integration test for my SpringBoot microservice that interacts with another service inside the product ecosystem.
Since this kind of testing is consider function/integration testing (depending on what nomenclature you use) it is usually done on some development environment.
However, I wanted to test a basic interaction between my service and a STUB/dummy app which are connected with RPC (so not exactly a typical TestRestTemplate test).
I know that there is a way to embed a service while booting up the Spring Context but have never done it by myself.
Does anyone have any experience with the upper or maybe a few helpful links where I can explore.
I have used WireMock in tests to mock services external to what I want to test that communicate over HTTP.
My test class annotated with #SpringBootTest is also annotated with #ContextConfiguration. In the classes attribute #ContextConfiguration I explicitly specify the configuration classes required to set up the Spring Context for the test in question. Here I can also include additional configuration classes in which I create beans only used in the test. In test configuration classes I can also override beans for the purpose of the test, creating mock beans etc.
Note that Spring Boot 2.1 and later disables bean overriding by default. It can be enabled by setting the following property to true:
spring.main.allow-bean-definition-overriding=true
To set the property for a single test, use the #TestPropertySource annotation like this:
#TestPropertySource(properties = {
"spring.main.allow-bean-definition-overriding=true"
})
Related
I understand that using #SpringbootTest I raise whole spring contex during test, or In my case using #SpringBootTest(classes = SomeController.class) I raise only one bean -> SomeController. If this controller have some dependencies I need to mock them up. Using annotation #WebMvcTest(SoneController.class) I will (based on my knowledge) achieve the same goal.
Question is: Are there any differences between those two annotations used in provided example?
There's a clear difference between #SpringBootTest(classes = SomeController.class) and #WebMvcTest(SomeController.class).
#SpringBootTest(classes = SomeController.class) - starts a server (i.e like Tomcat) + spring application context with the component SomeController.class. In addition to the controller, you should normally specify the context configuration to successfully start the whole app (For ex: when you don't specify the classes, it falls back to #SpringBootApplication).
#WebMvcTest(SomeController.class) - only starts the web layer of the application with SomeController.class.
What's the difference?
#SpringBootTest tests are usually integration tests, you start the full spring-boot application and test against that black box. You can still tweak the application startup by providing configuration, properties, web server type etc in the annotation parameters.
But #WebMvcTest(SomeController.class) is usually a unit test for your controller. These are lightweight and fast. The dependencies like #Service classes are mocked in such tests.
This is a good starting point - https://spring.io/guides/gs/testing-web/
There are several subtle differences between these two ways.
But you will discover a part of them only randomly when you will encounter problems such as bean initialization exception during the spring boot context init or a NullPointerException rising during the test execution.
To make things simpler, focus on intention.
When you write that :
#SpringBootTest(classes = SomeController.class)
you will make Spring to init only the SomeController bean instance.
Is it desirable to test a controller ?
Probably no since you need a way to invoke the controller with a controller approach.
For that a MockMvc instance would help.
With WebMvcTest you get that bean additionally loaded in the test context.
So that way is preferable :
#WebMvcTest(SomeController.class)
public class SomeControllerTest{
#Autowired
private MockMvc mvc;
...
}
Of course you could get a similar behavior with #SpringBootTest and some additional classes but it will be just an overhead : the #WebMvcTest specialized annotation is enough.
At last why make the reading of the test class harder for your follower ?
By weaving a contrived way of using spring boot test annotation, chances are good to come there.
I think for answering your question enough just read the Javadoc for both of these annotations:
1. #WebMvcTest
Annotation that can be used for a Spring MVC test that focuses only on Spring MVC components.
Using this annotation will disable full auto-configuration and instead apply only configuration relevant to MVC tests (i.e. #Controller, #ControllerAdvice, #JsonComponent, Converter/GenericConverter, Filter, WebMvcConfigurer and HandlerMethodArgumentResolver beans but not #Component, #Service or #Repository beans).
By default, tests annotated with #WebMvcTest will also auto-configure Spring Security and MockMvc (include support for HtmlUnit WebClient and Selenium WebDriver). For more fine-grained control of MockMVC the #AutoConfigureMockMvc annotation can be used.
#SpringbootTest
Annotation that can be specified on a test class that runs Spring Boot based tests. Provides the following features over and above the regular Spring TestContext Framework:
Uses SpringBootContextLoader as the default ContextLoader when no specific #ContextConfiguration(loader=...) is defined.
Automatically searches for a #SpringBootConfiguration when nested #Configuration is not used, and no explicit classes are specified.
Allows custom Environment properties to be defined using the properties attribute.
Allows application arguments to be defined using the args attribute.
Provides support for different webEnvironment modes, including the ability to start a fully running web server listening on a defined or random port.
Registers a TestRestTemplate and/or WebTestClient bean for use in web tests that are using a fully running web server.
We have a larger Spring boot application and a number of integration tests which are annotated by #SpringBootTest and having number of services.
Within the integration tests we have a number of them which are using #Sql to setup in memory db (as in real world) and having services which are reading values from the database base at the start time of the service.
Based on analysing/reading we have found that the order of initialisation is:
ServletTestExecutionListener – configures Servlet API mocks for a WebApplicationContext
DirtiesContextBeforeModesTestExecutionListener – handles the #DirtiesContext annotation for “before” modes
DependencyInjectionTestExecutionListener – provides dependency injection for the test instance
DirtiesContextTestExecutionListener – handles the #DirtiesContext annotation for “after” modes
TransactionalTestExecutionListener – provides transactional test execution with default rollback semantics
SqlScriptsTestExecutionListener – runs SQL scripts configured using the #Sql annotation
(Hint: The above list is copied from https://www.baeldung.com/spring-testexecutionlistener).
This means in consequence that it is not possible to write an integration tests with #SpringBootTest in which a service will read values from a database during the initialisation. This also means it's not possible to use #PostConstruct as alternative.
The question is: Is there an easy way to change that order?
I already tried to register a different test execution listener like this:
#TestExecutionListeners(
{
SqlScriptsTestExecutionListener.class,
ServletTestExecutionListener.class,
DirtiesContextBeforeModesTestExecutionListener.class,
DependencyInjectionTestExecutionListener.class,
DirtiesContextTestExecutionListener.class,
TransactionalTestExecutionListener.class
}
)
but it does not execute my scripts first (Maybe I'm doing something wrong).
Apart from that If I start the spring boot application with a service as described (reading values from database) above it will work perfectly which puzzles me a bit. Why is there a big difference between an integration test and the real world application?
Maybe I misunderstand a thing here, but it looks like the order in spring test (#SpringBootTest) is different than in real world application?
This question is related to Using JPA repository access in constructor of Service class
Is there a way to write unit tests to make sure spring boot API doesn't get started if a certain bean is failed to create. eg: failing to create datasource bean.
This code should do it for you:
#RunWith(SpringRunner.class)
#SpringBootTest
public class AnyAppNameApplicationTests {
#Test
public void contextLoads() {
}
}
From the docs:
Annotation that can be specified on a test class that runs Spring Boot
based tests. Provides the following features over and above the
regular Spring TestContext Framework:
Uses SpringBootContextLoader as the default ContextLoader when no specific #ContextConfiguration(loader=...) is defined.
Automatically searches for a #SpringBootConfiguration when nested #Configuration is not used, and no explicit classes are specified.
Allows custom Environment properties to be defined using the properties attribute.
Provides support for different webEnvironment modes, including the ability to start a fully running web server listening on a defined or
random port.
Registers a TestRestTemplate and/or WebTestClient bean for use in web tests that are using a fully running web server.
If you are using JUnit 4, don’t forget to also add
#RunWith(SpringRunner.class) to your test, otherwise the annotations
will be ignored. If you are using JUnit 5, there’s no need to add the
equivalent #ExtendWith(SpringExtension) as #SpringBootTest and the
other #…Test annotations are already annotated with it.
Conext
I found this question here but my problem is different.
So we are using Katharsis Controller and Spring Data Rest.
We only have 1 controller for entire application and then the request will be sent to Spring Data Rest repositories classes.
We want to use Spring Restdoc to generate documentation which requires us to write unit tests with MockMvc.
But when using Mockmvc, it starts up the container and will require datasources to be set up.
If we use standaloneSetup() and pass the mocked repository class, then MockMvc won't load Katharsis Controller and therefore the request won't reach that repository.
I understand that we can create an in-memory database but our project is big and the database needs a huge number of tables to be created we want to avoid that since these tests are for documentation purposes.
Question
Is there any way to achieve this and only mock the target repository class?
Note
By repository I mean CrudRepository interface in Spring DataRest.
As Andy Wilkinson suggested, you may consider creating unit test where you wire beans together by yourself and use MokMvc standalone setup.
If you want to create integration test and create Spring Context anyway, there is way to fake Spring bean by using #Primary, #ActiveProfiles and #Profile annotations. I wrote a blog post with GitHub example how to do it. You just need to combine this approach with WebApplicationContext based MockMvc setup. It works without problems, I wrote such tests in the past.
Ok, I come from Rails am having a bit of a hard time trying to get this working.
Right know this is what I understand from the Spring framework (and please correct me if I'm wrong):
I am using Tomcat. So what it does, basically, is go after web.xml, and check any configuration files from there in order to initialize and get beans auto wired, etc.
In my example, I have on web.xml the context config location as application-config.xml
It turns out that application-config.xml has other config files that will take care of the following:
Hibernate:
<util:properties id="hibernatePropertiesConfigurer" location="classpath:hibernate.properties"/>
JSon Converter:
<import resource="classpath:json-converter.xml"/>
Managers (#Component) Scanner:
<import resource="classpath:scanner-config.xml"/>
Among others. In other words, these work just fine, web server gets up, managers (#Components) are #Autowired, #Controllers can call them, persist objects in the database, etc.
Now, I want to test, i.e. run JUnit tests. I did find a lot of examples on how to mock these layers (managers, controllers) but I want to try the real thing:
Test will instantiate #Controller
Test will post to #Controller object
#Controller will have a real #Autowired (not mocked version) of #Component or #Bean
#Component will persist an #Entity
And, most important of all, database should see the changes. (I am using MySQL)
Test will, then, use an #Autowired instance of #Component, and query the database to confirm the persistence occurred.
Is this possible, at all, with Spring, JUnit testing?
If you want to verify the behavior of the entire stack like that, it's no longer a unit test, but an integration test.
If you're using Maven, you can use something like the Maven Jetty plugin to deploy your project into an embedded container during the pre-integration-test phase. Then in your tests, make the HTTP calls to the server at localhost, and verify you get the expected responses. Then, in the post-integration-test phase, shut down the Jetty server.