[DataSource 자동 구성 클래스 테스트] properties와 yml의 차이점 관련 질문입니다.

안녕하세요, 강사님.

섹션 9-2, DataSource 자동 구성 클래스에서, connect() 을 테스트하는 코드에서 yml파일을 이용했을 때, 테스트 실패를 하여 질문글 드립니다.

먼저 강의와 동일하게 properties 파일을 이용한다면 정상적으로 테스트가 통과됩니다.

application.properties

DataSourceTest

평소에 yml 파일을 더 선호하여, yml 파일로 변경한 후, 테스트 코드 상에서 @TestPropertySource("classpath:/application.yml") 로 classpath를 properties에서 yml로 바꿨을 뿐, 기존과 동일한 환경에서 테스트를 진행해봤습니다.

application.yml

DataSourceTest

하지만, 아래와 같은 에러 로그가 발생하며 테스트에 실패하게 됩니다.

에러 로그

java.lang.IllegalStateException: Failed to load ApplicationContext

	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:98)
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:124)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:248)
	at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:138)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$8(ClassBasedTestDescriptor.java:363)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.executeAndMaskThrowable(ClassBasedTestDescriptor.java:368)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$9(ClassBasedTestDescriptor.java:363)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1655)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:312)
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:735)
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734)
	at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.invokeTestInstancePostProcessors(ClassBasedTestDescriptor.java:362)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$instantiateAndPostProcessTestInstance$6(ClassBasedTestDescriptor.java:283)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.instantiateAndPostProcessTestInstance(ClassBasedTestDescriptor.java:282)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$4(ClassBasedTestDescriptor.java:272)
	at java.base/java.util.Optional.orElseGet(Optional.java:369)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$5(ClassBasedTestDescriptor.java:271)
	at org.junit.jupiter.engine.execution.TestInstancesProvider.getTestInstances(TestInstancesProvider.java:31)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$prepare$0(TestMethodTestDescriptor.java:102)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:101)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:66)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$prepare$2(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.prepare(NodeTestTask.java:123)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:90)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
	at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
	at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:57)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'tobyspring.config.autoconfig.ServerProperties': Initialization of bean failed; nested exception is org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'server' to tobyspring.config.autoconfig.ServerProperties
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:628)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:955)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:920)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
	at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:127)
	at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60)
	at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:276)
	at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:244)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:141)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:90)
	... 71 more
Caused by: org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'server' to tobyspring.config.autoconfig.ServerProperties
	at org.springframework.boot.context.properties.bind.Binder.handleBindError(Binder.java:387)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:347)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:332)
	at org.springframework.boot.context.properties.bind.Binder.bindOrCreate(Binder.java:324)
	at org.springframework.boot.context.properties.bind.Binder.bindOrCreate(Binder.java:293)
	at org.springframework.boot.context.properties.bind.Binder.bindOrCreate(Binder.java:278)
	at tobyspring.config.autoconfig.PropertyPostProcessorConfig$1.postProcessAfterInitialization(PropertyPostProcessorConfig.java:30)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:455)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1808)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620)
	... 85 more
Caused by: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.String] to type [tobyspring.config.autoconfig.ServerProperties]
	at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:118)
	at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:100)
	at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:92)
	at org.springframework.boot.context.properties.bind.Binder.bindProperty(Binder.java:459)
	at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:403)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:343)
	... 93 more

에러 로그를 확인한 후, ServerProperties가 제대로 바인딩 되지 않음을 확인하였습니다.

바인딩이 테스트 환경이 아닌, 일반 서버를 구동할 때도 제대로 안되는건가? 라는 의구심에 로그를 찍어보며 이를 확인해봤습니다.

로그 출력

PropertyPostProcessorConfig

TomcatWebServerConfig

DataSourceConfig

로그 출력 확인 (일반 서버 구동)

테스트 환경이 아닌 일반 서버를 실행시, 위의 결과와 마찬가지로 제대로 바인딩됨을 확인하였습니다. 따라서, 테스트 코드상에서 바인딩이 제대로 이뤄지지 않음을 알게 되었고, 스프링부트 레퍼런스를 찾아보니 yml 파일은 @PropertySource와 @TestPropertySource를 통해 로딩되지 않음을 확인하였습니다.

(https://docs.spring.io/spring-boot/docs/current/reference/html/features.html#boot-features-external-config-yaml-shortcomings) 

이를 해결하기 위해, 구글링을 통해 해결방법을 참고하여 아래와 같이 변경하였더니, 테스트가 제대로 통과됨을 확인하였습니다.

(참고링크 : https://www.inflearn.com/questions/293325/testpropertysource%EC%A7%88%EB%AC%B8%EC%9E%85%EB%8B%88%EB%8B%A4 )

하지만 이전 토비님의 질문 답변 중, @SpringBootTest와 @ExtendWith + @ContextConfiguration 의 차이점에 대한 글을 보게 되었습니다.

(https://www.inflearn.com/questions/834733/springboottest%EC%99%80-extendwith-contextconfiguration-%EC%B0%A8%EC%9D%B4%EA%B0%80-%EA%B6%81%EA%B8%88%ED%95%A9%EB%8B%88%EB%8B%A4)

혹시 @ExtendWith + @ContextConfiguration 을 유지한 채, yml 파일을 이용하여 해당 테스트를 통과할 수 있는 방법이 존재하는지 궁금합니다.

항상 수준 높은 강의에 감사드립니다.