Mockito 디버깅: Gradle 플러그인 테스트에서 'Wanted but not invoked' 오류 해결하기
게시: 17 November 2024
서론
Gradle 플러그인 개발 중베이커리내 JBake 블로그에서 겉보기에 간단한 문제를 만났습니다: 오류와 함께 실패하는 단위 테스트가 있었습니다.Wanted but not invoked. 이것은 사소한 버그로 보였지만 Mockito와 Kotlin을 사용한 모킹의 미묘함을 이해하기에 완벽한 사례임이 밝혀졌다.
이 글에서는 체계적인 디버깅 여정을 안내하며, 각 해결책이 새로운 문제를 드러내고 최종 해결에 이르기까지의 과정을 보여줍니다.
컨텍스트 : Plugin Gradle Bakery
Bakery 플러그인은 JBake를 감싸는 래퍼로, 정적 사이트 게시를 용이하게 합니다. 다음은 간소화된 구조 :
class BakeryPlugin : Plugin<Project> {
override fun apply(project: Project) {
val extension = project.extensions.create(
"bakery",
BakeryExtension::class.java
)
project.afterEvaluate {
if (!project.layout.projectDirectory.asFile
.resolve(extension.configPath.get()).exists()) {
println("config file does not exists")
} else {
// C'EST ICI QUE ÇA SE PASSE
project.plugins.apply(JBakePlugin::class.java)
val site = FileSystemManager.from(project, extension.configPath.get())
// Configuration de JBake...
}
}
}
}
실패하던 테스트는 간단했습니다 :
@Test
fun `plugin applies jbake gradle plugin`() {
val project = createMockProject()
val plugin = BakeryPlugin()
plugin.apply(project)
verify(project.plugins).apply(JBakePlugin::class.java)
}
오류 :
Wanted but not invoked:
pluginContainer.apply(class org.jbake.gradle.JBakePlugin);
Actually, there were zero interactions with this mock.
문제 #1 : 잘못된 모의(mock) 확인
진단
@startuml actor Test participant "project.plugins" as PP participant "모의플러그인컨테이너" as MPC participant "BakeryPlugin" as BP Test -> Test: createMockProject() activate Test Test -> MPC: create mock Test -> PP: doReturn mockPluginContainer Test --> Test: return project deactivate Test Test -> BP: apply(project) activate BP BP -> PP: project.plugins PP --> BP: returns mockPluginContainer BP -> MPC: apply(JBakePlugin::class.java) deactivate BP Test -> PP: verify(project.plugins).apply(...) note right ❌ ÉCHEC ! Mockito vérifie "project.plugins" mais l'interaction a eu lieu sur "모의플러그인컨테이너" end note @enduml
문제: Mockito는 상호작용을 추적할 수 없습니다.project.plugins`그냥 진짜 모의를 반환하는 getter일 뿐이다`mockPluginContainer. 확인은 모의 객체의 인스턴스에서 직접 수행해야 합니다.
해결책
수정`createMockProject()`두 객체를 반환하기 위해 :
private fun createMockProject(): Pair<Project, PluginContainer> {
val mockPluginContainer = mock<PluginContainer>()
val mockProject = mock<Project> {
on { plugins } doReturn mockPluginContainer
}
return Pair(mockProject, mockPluginContainer)
}
그리고 테스트를 조정:
@Test
fun `plugin applies jbake gradle plugin`() {
val (project, mockPluginContainer) = createMockProject()
val plugin = BakeryPlugin()
plugin.apply(project)
// ✅ Vérification directe sur le bon mock
verify(mockPluginContainer).apply(JBakePlugin::class.java)
}
문제 #2: 연속된 UnfinishedStubbingException
진단
첫 번째 수정이 적용된 후, 새로운 오류가 나타났습니다:
UnfinishedStubbingException:
Unfinished stubbing detected here
Hints:
3. you are stubbing the behaviour of another mock inside
before 'thenReturn' instruction is completed
문제가 있는 코드에서는 Mockito-Kotlin의 DSL 구문을 사용했습니다 :
val mockProject = mock<Project> {
on { extensions } doReturn mockExtensionContainer
on { plugins } doReturn mockPluginContainer
on { logger } doReturn mock() // ❌ PROBLÈME ICI !
}
@startuml
participant "Mockito" as M
participant "모크 빌더" as MB
participant "인라인 모의" as IM
M -> MB: mock<Project> { ... }
activate MB
MB -> MB: on { logger } doReturn
MB -> IM: mock()
activate IM
note right
❌ Création d'un nouveau mock
PENDANT le stubbing en cours !
Mockito perd le contexte
du stubbing parent
end note
IM --> MB: nouveau mock
deactivate IM
MB -x M: UnfinishedStubbingException
deactivate MB
@enduml
해결책
만들다모두그리고 이를 구성합니다`whenever()` :
private fun createMockProject(): Pair<Project, PluginContainer> {
// 1️⃣ Créer TOUS les mocks d'abord
val mockPluginContainer = mock<PluginContainer>()
val mockExtensionContainer = mock<ExtensionContainer>()
val mockLogger = mock<org.gradle.api.logging.Logger>()
val mockProject = mock<Project>()
// 2️⃣ Configurer les mocks séparément avec whenever()
whenever(mockProject.plugins).thenReturn(mockPluginContainer)
whenever(mockProject.extensions).thenReturn(mockExtensionContainer)
whenever(mockProject.logger).thenReturn(mockLogger)
return Pair(mockProject, mockPluginContainer)
}
|
황금 규칙: 절대 부르지 마`mock()`모의 구성 블록 안에. 항상 먼저 mock을 생성한 다음 구성하세요. |
문제 #3 : 구성 파일이 존재하지 않습니다.
진단
올바른 목(mock) 객체가 있더라도, 플러그인이 구성 파일을 찾지 못해서 테스트는 항상 실패했습니다 :
// Dans BakeryPlugin.kt
if (!project.layout.projectDirectory.asFile
.resolve(extension.configPath.get()).exists()) {
println("config file does not exists")
return@afterEvaluate // ❌ Sort avant d'appliquer JBake !
}
@startuml
participant "베이커리플러그인" as BP
participant "프로젝트 레이아웃" as PL
participant "확장" as EXT
participant "파일 시스템" as FS
BP -> PL: layout.projectDirectory.asFile
PL --> BP: /some/mock/path
BP -> EXT: extension.configPath.get()
EXT --> BP: "../../site.yml"
BP -> BP: resolve("../../site.yml")
BP -> FS: exists() ?
FS --> BP: false ❌
BP -> BP: return (skip JBake)
note right
Le plugin ne trouve pas
le fichier et sort
avant d'appliquer JBake
end note
@enduml
해결책
경로 해결이 작동하도록 모의(mock)를 구성합니다 :
private fun createMockProject(): Pair<Project, PluginContainer> {
// ... autres mocks ...
val configFile = File("../../site.yml").canonicalFile
val projectDir = configFile.parentFile
// Configuration cohérente des chemins
whenever(mockConfigPathProperty.get()).thenReturn("site.yml")
whenever(mockProjectDirectory.asFile).thenReturn(projectDir)
// Maintenant : projectDir.resolve("site.yml") existe ! ✅
}
@startuml
!define SUCCESS #90EE90
!define PROBLEM #FFB6C1
rectangle "모의 구성" {
card "projectDirectory.asFile" SUCCESS
card "반환: /real/path/to/project" SUCCESS
card "configPath.get()" SUCCESS
card "반환: site.yml" SUCCESS
card "resolve()" SUCCESS
card "/real/path/to/project/site.yml" SUCCESS
card "존재()" SUCCESS
card "참 ✅" SUCCESS
}
@enduml
문제 #4 : afterEvaluate 와 NullPointerException
진단
플러그인은 블록에서 JBake를 적용합니다.afterEvaluate, 그리고 접근한다`buildDirectory.dir()` :
project.afterEvaluate {
// ...
project.tasks.withType(JBakeTask::class.java)
.getByName("bake").apply {
output = project.layout.buildDirectory
.dir(site.bake.destDirPath) // ❌ NPE ici !
.get()
.asFile
}
}
모의`buildDirectory.dir()돌아가고 있었다`null.
해결책
조롱하다`afterEvaluate`즉시 실행되도록 하고 완전히 설정하다`buildDirectory`:
private fun createMockProject(): Pair<Project, PluginContainer> {
// ... autres mocks ...
val mockBuildDirectory = mock<DirectoryProperty>()
val buildDir = File(projectDir, "build")
// Mocker dir() pour retourner un Provider valide
whenever(mockBuildDirectory.dir(any<String>())).doAnswer { invocation ->
val path = invocation.arguments[0] as String
val mockDirProvider = mock<Provider<Directory>>()
val mockDir = mock<Directory>()
whenever(mockDir.asFile).thenReturn(File(buildDir, path))
whenever(mockDirProvider.get()).thenReturn(mockDir)
mockDirProvider
}
// Mocker afterEvaluate pour exécution immédiate
whenever(mockProject.afterEvaluate(any<Action<Project>>())).doAnswer { invocation ->
val action = invocation.arguments[0] as Action<Project>
action.execute(mockProject) // ✅ Exécution synchrone
null
}
return Pair(mockProject, mockPluginContainer)
}
@startuml
participant "테스트" as T
participant "베이커리 플러그인" as BP
participant "모의 프로젝트" as MP
participant "후평가 액션" as AE
T -> BP: apply(project)
activate BP
BP -> MP: afterEvaluate { ... }
activate MP
note right
Mock configuré pour
exécuter immédiatement
end note
MP -> AE: execute(project)
activate AE
AE -> MP: layout.buildDirectory.dir("구우다")
MP --> AE: Provider<Directory> ✅
AE -> MP: plugins.apply(JBakePlugin)
deactivate AE
MP --> BP:
deactivate MP
BP --> T:
deactivate BP
T -> T: verify(mockPluginContainer).apply(...)
note right: ✅ SUCCÈS !
@enduml
완전한 솔루션
여기에 함수입니다.`createMockProject()`마지막으로, 모든 문제를 해결하는 :
private fun createMockProject(): Pair<Project, PluginContainer> {
// 1️⃣ CRÉER tous les mocks (pas de nested mocks !)
val mockPluginContainer = mock<PluginContainer>()
val mockExtensionContainer = mock<ExtensionContainer>()
val mockLogger = mock<org.gradle.api.logging.Logger>()
val mockTaskContainer = mock<TaskContainer>()
val mockConfigPathProperty = mock<Property<String>>()
val mockBakeryExtension = mock<BakeryExtension>()
val mockProjectDirectory = mock<Directory>()
val mockBuildDirectory = mock<DirectoryProperty>()
val mockProjectLayout = mock<ProjectLayout>()
val mockProject = mock<Project>()
// 2️⃣ CONFIGURER la résolution des chemins
val configFile = File("../../site.yml").canonicalFile
val projectDir = configFile.parentFile
val buildDir = File(projectDir, "build")
whenever(mockConfigPathProperty.get()).thenReturn("site.yml")
whenever(mockConfigPathProperty.isPresent).thenReturn(true)
whenever(mockBakeryExtension.configPath).thenReturn(mockConfigPathProperty)
whenever(mockProjectDirectory.asFile).thenReturn(projectDir)
// 3️⃣ CONFIGURER buildDirectory avec dir()
whenever(mockBuildDirectory.dir(any<String>())).doAnswer { invocation ->
val path = invocation.arguments[0] as String
val mockDirProvider = mock<Provider<Directory>>()
val mockDir = mock<Directory>()
whenever(mockDir.asFile).thenReturn(File(buildDir, path))
whenever(mockDirProvider.get()).thenReturn(mockDir)
mockDirProvider
}
// 4️⃣ ASSEMBLER le projet
whenever(mockProjectLayout.projectDirectory).thenReturn(mockProjectDirectory)
whenever(mockProjectLayout.buildDirectory).thenReturn(mockBuildDirectory)
whenever(mockExtensionContainer.create("bakery", BakeryExtension::class.java))
.thenReturn(mockBakeryExtension)
whenever(mockExtensionContainer.getByType(BakeryExtension::class.java))
.thenReturn(mockBakeryExtension)
whenever(mockProject.extensions).thenReturn(mockExtensionContainer)
whenever(mockProject.plugins).thenReturn(mockPluginContainer)
whenever(mockProject.tasks).thenReturn(mockTaskContainer)
whenever(mockProject.layout).thenReturn(mockProjectLayout)
whenever(mockProject.logger).thenReturn(mockLogger)
whenever(mockProject.projectDir).thenReturn(projectDir)
// 5️⃣ CONFIGURER afterEvaluate pour exécution immédiate
whenever(mockProject.afterEvaluate(any<Action<Project>>())).doAnswer { invocation ->
val action = invocation.arguments[0] as Action<Project>
action.execute(mockProject)
null
}
return Pair(mockProject, mockPluginContainer)
}
그리고 최종 테스트가 통과됩니다:
@Test
fun `plugin applies jbake gradle plugin`() {
val (project, mockPluginContainer) = createMockProject()
val plugin = BakeryPlugin()
plugin.apply(project)
verify(mockPluginContainer).apply(JBakePlugin::class.java) // ✅ SUCCÈS !
}
배운 점
@startmindmap * Mocking avec Mockito ** ✅ Bonnes pratiques *** Créer tous les mocks d'abord *** Configurer avec whenever() séparément *** Vérifier le mock exact, pas un proxy *** Tester la résolution des chemins ** ❌ Pièges à éviter *** mock() dans un bloc de configuration *** Vérifier project.x au lieu de mockX *** Ignorer les blocs afterEvaluate *** Retourner null pour les Providers @endmindmap
1. 올바른 모의 객체 확인
// ❌ FAUX
verify(project.plugins).apply(JBakePlugin::class.java)
// ✅ CORRECT
val (project, mockPluginContainer) = createMockProject()
verify(mockPluginContainer).apply(JBakePlugin::class.java)
2. 중첩된 모의 객체 피하기
// ❌ FAUX - UnfinishedStubbingException
val mockProject = mock<Project> {
on { logger } doReturn mock() // Nested mock creation !
}
// ✅ CORRECT - Créer séparément
val mockLogger = mock<org.gradle.api.logging.Logger>()
val mockProject = mock<Project>()
whenever(mockProject.logger).thenReturn(mockLogger)
3. 평가 콜백을 모의하기
// ✅ afterEvaluate doit s'exécuter pour les tests
whenever(mockProject.afterEvaluate(any())).doAnswer { invocation ->
val action = invocation.arguments[0] as Action<Project>
action.execute(mockProject)
null
}
4. 경로 해결 테스트
// Toujours vérifier que les chemins se résolvent correctement
val extension = project.extensions.getByType(BakeryExtension::class.java)
val configPath = extension.configPath.get()
val projectDir = project.layout.projectDirectory.asFile
val resolvedConfig = projectDir.resolve(configPath)
println("Resolved config: ${resolvedConfig.absolutePath}")
println("Exists: ${resolvedConfig.exists()}")
최종 테스트 아키텍처
@startuml
package "테스트 레이어" {
[Test Class] --> [createMockProject()]
}
package "모의 창조" {
[createMockProject()] --> [Create All Mocks]
[Create All Mocks] --> [Configure Paths]
[Configure Paths] --> [Configure Callbacks]
[Configure Callbacks] --> [Assemble Project]
}
package "모의 객체" {
[Assemble Project] --> [Project Mock]
[Assemble Project] --> [PluginContainer Mock]
[Assemble Project] --> [Extension Mocks]
[Assemble Project] --> [Layout Mocks]
}
package "플러그인 테스트 중" {
[Test Class] --> [BakeryPlugin]
[BakeryPlugin] --> [Project Mock]
[BakeryPlugin] --> [PluginContainer Mock]
}
package "검증" {
[Test Class] --> [verify(mockPluginContainer)]
}
@enduml
결론
테스트 문제처럼 보였던 것이 실제로 훌륭한 사례 연구가 된 것은 :
-
Mockito와 Kotlin의 세부 사항
-
올바른 객체를 모의하는 것의 중요성
-
테스트에서의 비동기 콜백 관리
-
Gradle 플러그인에서의 경로 해결
체계적인 디버깅으로 문제를 구성하는 각 층을 이해함으로써 견고하고 유지 가능한 솔루션에 도달할 수 있었다.
|
당신의 테스트를 위한 조언Mockito에서 "Wanted but not invoked"을(를) 마주치면 항상 스스로에게 물어보세요: 1. 올바른 mock을 확인하고 있나요? 2. 모든 mock이 구성 블록 외부에서 생성됩니까? 3. 내 콜백이 정말 실행되고 있나요? 4. 내 경로가 올바르게 해결되고 있나요? |
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