Mocking a #Bean defined in a #ConfigurationProperties Class - spring

I have a #ConfigurationProperties class like this:
#ConfigurationProperties(prefix = "myprops", ignoreUnknownFields = false)
#Configuration
public class MyProperties {
private Long mySchedulerRate;
#Bean
public Long mySchedulerRate() {
return this.mySchedulerRate;
}
}
I'm registering it as a bean so I can refer to it in an annotation for a Spring scheduler:
#Scheduled(fixedRateString = "#{#mySchedulerRate}")
public void runScheduledUpdate() {
...
{
However, I now want to write a unit test where I want to be able to set a different value for the bean 'mySchedulerRate'. Mocking/Spying on the #ConfigurationProperties class doesnt seem to work since the scheduler gets set up before the stubbing has been set to return my desired value.
What is the easiest way to achieve what I am trying to do?

Managed to fix this now. I was running a #SpringBootTest and I realise you can override properties here within the annotation for a particular test class.
This worked for me:
#RunWith(SpringRunner.class)
#SpringBootTest(classes = MyApp.class, properties = "myprops.my-scheduler-rate=1000")
public class MyTest {
So no need to try and override the bean, I was overcomplicating this far too much.

Related

Is there a way to overide automatically injected beans in Spring boot when writing tests?

I have a class annotated with a spring bean #Repository("clientDatasource") called ClientServiceDatasource which implements an interface called Datasource. I also have a mock implementation of this interface also annotated with a spring bean #Repository("mockDatasource") called MockClientServiceDatasource. I also have a class annotated with the spring bean #Service called ClientService and in in its constructor, I pass in a datasource. I do it like so:
#Service
class ClientService (#Qualifier("clientDatasource") private val dataSource: Datasource){}
As you can see that the service will default to the clientDatasource, because of the #Qualifier when the application is running.
However when I run my tests I annotate my test class with #SpringTest . In my understanding this means that it boots up the entire application as if it were normal. So I want to somehow overide that #Qualifier bean thats being used in the client service in my test so that the Client Service would then use the mockedDatasource class.
I'm fairly new to kotlin and spring. So I looked around and found ways to write a testConfig class to configure beans like so :
#TestConfiguration
class TestConfig {
#Bean
#Qualifier("clientDatasource")
fun mockDatasource(): Datasource {
return MockClientServiceDatasource()
}
}
and then using it in the test like so:
#SpringTest
#Import(TestConfig::class)
class ClientServiceTest {
...
}
I also asked chatGPT and it gave me this:
#SpringBootTest
class ClientServiceTest {
#Autowired
lateinit var context: ApplicationContext
#Test
fun testWithMockedDatasource() {
// Override the clientDatasource bean definition with the mockDatasource bean
val mockDatasource = context.getBean("mockDatasource", Datasource::class.java)
val mockClientDatasourceDefinition = BeanDefinitionBuilder.genericBeanDefinition(MockClientServiceDatasource::class.java)
.addConstructorArgValue(mockDatasource)
.beanDefinition
context.registerBeanDefinition("clientDatasource", mockClientDatasourceDefinition)
// Now the ClientService should use the mockDatasource when it's constructed
val clientService = context.getBean(ClientService::class.java)
// ... do assertions and other test logic here ...
}
}
But some of the methods don't work, I guess chatGPT knowledge is outdated.
I also looked through spring docs, but couldn't find anything useful.
Okay, So I took a look at the code previously with the TestConfig class. And I realised by adding the:
#Primary
annotation to the method inside my TestConfig class, it basically forces that to be the primary repository bean. Like so:
#TestConfiguration
class TestConfiguration {
#Bean
#Primary
#Qualifier("clientDatasource")
fun mockDatasource(): Datasource {
return MockClientDataSource()
}
}
and in the test I only imported the test and it just worked. I didn't have to autowire anything
This is my test class:
#SpringBootTest
#AutoConfigureMockMvc
#Import(TestConfiguration::class)
internal class ServiceControllerTest{
#Suppress("SpringJavaInjectionPointsAutowiringInspection")
#Autowired
lateinit var mockMvc: MockMvc
#Test
fun `should return all clients` () {
// when/then
mockMvc.get("/clients")
.andDo { print() }
.andExpect {
status { isOk() }
content { contentType(MediaType.APPLICATION_JSON) }
jsonPath("$[0].first_name") {value("John")}
}
}
}

"No converter found for return value" when running Spring Boot MockMvc test

I'm trying to create a MockMvc test of a Spring Boot controller. I specifically do not want the entire application context to be spun up, so I am restricting the context to the controller in question. However, the test fails with a 500 with the following log output:
2020-03-03 13:04:06.904 WARN 8207 --- [ main] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type: class main.endpoints.ResponseDto]
It appears that the Spring Boot context does not know how to find Jackson.
Here is the controller
#RestController
class MyController {
#GetMapping("/endpoint")
fun endpoint(): ResponseDto {
return ResponseDto(data = "Some data")
}
}
data class ResponseDto(val data: String)
The test is as follows:
#SpringBootTest(
classes = [MyController::class],
webEnvironment = SpringBootTest.WebEnvironment.MOCK
)
#AutoConfigureMockMvc
internal class MyControllerTest(#Autowired private val mockMvc: MockMvc) {
#Test
fun `should work`() {
mockMvc.perform(MockMvcRequestBuilders.get("/endpoint").accept(MediaType.APPLICATION_JSON))
.andExpect(
content().json(
"""
{
"data": "Some data"
}
"""
)
)
}
}
The build.gradle file includes the following dependencies:
def jacksonVersion = "2.10.2"
testImplementation("com.fasterxml.jackson.core:jackson-core:2.10.2")
testImplementation("com.fasterxml.jackson.core:jackson-databind:2.10.2")
testImplementation("com.fasterxml.jackson.core:jackson-annotations:2.10.2")
Any ideas on how to get this to work?
The solution is to annotate the class with #WebMvcTest rather than #SpringBootTest. This configures enough context that the test can interact via MockMvc with the controller.
Unfortunately, enabling #WebMvcTest has another side effect: all beans specified by #Bean-annotated methods in the configuration are also instantiated. This is a problem when those methods cannot be executed in a test environment (e.g. because they access certain environment variables).
To solve this, I added the annotation #ActiveProfiles("test") to the test and #Profile("!test") to each such annotated method. This suppresses the invocation of those methods and the test works.
I'm not sure, but I think you need to specify what format the output will be. So something like
#GetMapping(value = ["/endpoint"], produces = [MediaType.APPLICATION_JSON])
So that spring knows to convert it to json and not say XML or something.
#EnableWebMvc might solve your issue.
According to Java Doc:
Adding this annotation to an #Configuration class imports the Spring MVC configuration from WebMvcConfigurationSupport,
e.g.:
#Configuration
#EnableWebMvc
#ComponentScan(basePackageClasses = MyConfiguration.class)
public class MyConfiguration {
}
To customize the imported configuration, implement the interface WebMvcConfigurer and override individual methods, e.g.:
#Configuration
#EnableWebMvc
#ComponentScan(basePackageClasses = MyConfiguration.class)
public class MyConfiguration implements WebMvcConfigurer {
#Override
public void addFormatters(FormatterRegistry formatterRegistry) {
formatterRegistry.addConverter(new MyConverter());
}
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(new MyHttpMessageConverter());
}
}

Mockito mock does not work as expected in Spring MockMvc test

In an Spring mockmvc test I want to replace a bean by a mock implementation which is configured using Mockito.when() definitions. The definitions are indeed respected at the time the mock is configured, as well as at the time the mock is injected into a depending bean (a controller advice in my case) during application context startup. However, when the mock is used during a certain test, all when definitions are gone.
Why?
Some remarks:
The mock is completely new code, so it is impossible that I am not aware of any call to Mockito.reset().
the mock at the time of usage is the same as at the time of creation.
a bypassing solution to the problem is to configure the mock in a #BeforeEach method in AbstractTest. However, I want to understand why it does not work without.
Here a simplified and anonymized example
#Component
public class MyBean {
private String property;
...
public String getProperty() {
return property;
}
}
#ControllerAdvice
public class MyControllerAdvice() {
private MyBean myBean;
#Autowired
public MyControllerAdvice(MyBean myBean) {
this.myBean = myBean;
System.out.println(this.myBean.getProperty()); // --> outputs "FOOBAR"
}
#ModelAttribute
public String getMyBeanProperty() {
return myBean.getProperty(); // --> returns null
}
}
public class AbstractTest {
#Configuration
static class Config {
#Bean
public MyBean () {
MyBean myBean = Mockito.mock(MyBean.class, "I am a mock of MyBean");
when(myBean.getProperty()).thenReturn("FOOBAR");
}
}
}
That's not a problem of Mockito. I think you simplified the example a lot and we don't see the full picture, but I can say that main cause - 2 different beans MyBean: one is initialized with Spring's #Component, second is in configuration class with #Bean.
Why do you use #Component for POJO/DO?
#Bean in the configuration class is being initialized lazy so better way to use #PostConstruct
If you want to leave both beans mark MyBean in the configuration class as #Primary

Spring annotation to initialize a bean during Autowire

Do we have a spring annotation that provides an option to initialize a bean (not a component) if not available through default constructor while autowiring?
If yes, that will be awesome. I am tired of initializing beans in some configuration class using default constructor and it occupies space.
I am doing this currently
#Bean
public Test test() {
return new Test();
}
Expecting:
Sometime like:
#Autowire(initMethodType=constructor)
private Test test:
If no, was there no real need of such annotation or any technical limitation?
You have to use #Bean annotation inside an #Configuration class.
Check the following link
https://docs.spring.io/spring-javaconfig/docs/1.0.0.M4/reference/html/ch02s02.html
#Configuration
public class AppConfig {
#Bean
public TransferService transferService() {
return new TransferServiceImpl();
}
}
You could annotate your class with #Component, like this:
#Component
public class Test {
...
}
Whereever you need that class, you could then simply autowire it:
#Autowired
private Test test;
You would just have to make sure, that you use #ComponentScan to pick up that bean. You can find more information on that here.

How do I post-process beans of #Configuration classes that define more #Beans in JavaConfig?

In Spring XML, I can define a bean that instantiates a class annotated with #Configuration. When I do, that bean is post-processed. Any methods inside that class with #Bean are also added to the container. How do I perform a similar post-processing in JavaConfig?
Here's the XML version:
<bean id="test" class="com.so.Test">
<property name="prop" value="set before instantiating #Beans defined in Test"/>
</bean>
The associated Test class:
#Configuration
class Test {
private String prop;
void setProp(final String prop) {
this.prop = prop;
}
#Bean
NeedThisBean needThisBeanToo() {
return new NeedThisBean(prop);
}
}
If I use Spring XML Config, both test and needThisBeanToo are available in the container. needThisBeanToo is added via a BeanPostProcessor, though I can't recall which one. If I use JavaConfig, only test is available in the container. How do I make needThisBeanToo available to the container? #Import would work, except that prop being set is required for needThisBeanToo to be initialized correctly.
The part that makes all of this complicated is that Test is vended from a library I'm consuming. I don't control Test, nor can I change it. If I drive it from JavaConfig, it would look like this:
#Configuration
class MyConfiguration
{
#Bean
Test test() {
Test test = new Test();
test.setProp("needed to init `needThisBeanToo` and others");
return test;
}
}
The JavaConfig example does not instantiate needThisBeanToo despite it being defined in Test. I need to get needThisBeanToo defined, preferably without doing it myself, since I don't want to copy code I don't own. Delegation isn't attractive, since there are a number of subsequent annotations/scopes defined on needThisBeanToo (and others defined inside Test).
Your problem is is that you're ignoring the #Configuration annotation completely. Why is that?
When code reaches this line Test test = new Test(); it just doesn't do anything with #Configuration. Why? Because annotation is not something that a constructor is aware of. Annotation only marks some meta-data for the class. When spring loads classes it searches for annotations, when you call a constructor of a class, you don't. So the #Configuration is just ignored because you instantiate Test with new Test() and not through spring.
What you need to do is to import Test as a spring bean. Either via XML as you showed in your question OR using #Import. You problem with prop is that the setter isn't called because that's just not the way to do it. What you need to be doing is either do something like that:
#Configuration
class Test {
private String prop = "set before instantiating #Beans defined in Test";
#Bean
NeedThisBean needThisBeanToo() {
return new NeedThisBean(prop);
}
}
Or to create a property in spring (this is a different subject) and inject the value:
#Configuration
class Test {
#Autowired
#Value("${some.property.to.inject}") // You can also use SPeL syntax with #{... expression ...}
private String prop;
#Bean
NeedThisBean needThisBeanToo() {
return new NeedThisBean(prop);
}
}
You can also create a bean of type String and inject it as follows:
#Configuration
class Test {
#Autowired
#Qualifer("nameOfBeanToInject")
private String prop;
#Bean
NeedThisBean needThisBeanToo() {
return new NeedThisBean(prop);
}
}
In the last case you can define your original MyConfiguration with this bean:
#Configuration
#Import(Test.class)
class MyConfiguration
{
#Bean(name = "nameOfBeanToInject")
String test() {
return "needed to init `needThisBeanToo` and others";
}
}
In any case you have to import Test either using #Import or as a normal XML bean. It won't work by calling the constructor explicitly.
Here's a way to handle vended #Configuration classes that require some properties to be set prior to creating their #Beans:
Vended #Configuration class:
#Configuration
class Test {
private String property;
public setProperty(final String property) {
this.property = property;
}
#Bean
PropertyUser propertyUser() {
return new PropertyUser(property);
}
#Bean
SomeBean someBean() {
// other instantiation logic
return new SomeBeanImpl();
}
}
Here's the consuming #Configuration class:
#Configuration
class MyConfig {
#Bean
static String myProperty() {
// Create myProperty
}
/**
* Extending Test allows Spring JavaConfig to create
* the beans provided by Test. Declaring
* Test as a #Bean does not provide the #Beans defined
* within it.
*/
#Configuration
static class ModifiedTest extends Test {
ModifiedTest() {
this.setProperty(myProperty());
}
#Override
#Bean
SomeBean someBean() {
return new SomeBeanCustomImpl(this.propertyUser());
}
}

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