• Database has to be cleaned after each integration test so that every test is independent each other
• Sometimes Test case is not represents real applications transaction scope
• Clean up database manually after each test is more concise and reliable

Solution

Implementation

 class JpaDatabaseCleanerExtension : AfterEachCallback {

    private lateinit var tableNames: List<String>

    override fun afterEach(context: ExtensionContext?) {
        if (context == null) {
            throw IllegalStateException("No extension context found")
        }
        if (!this::tableNames.isInitialized) {
            SpringExtension.getApplicationContext(context).getBean(EntityManager::class.java)
                .also { entityManager -> entityManager.initTableNames() }
        }
        SpringExtension.getApplicationContext(context).getBean(DataSource::class.java)
            .also { dataSource ->
                dataSource.connection.use { connection ->
                    connection.prepareStatement("SET REFERENTIAL_INTEGRITY FALSE").executeUpdate()
                    tableNames.forEach { name -> connection.prepareStatement("TRUNCATE TABLE $name").executeUpdate() }
                    connection.prepareStatement("SET REFERENTIAL_INTEGRITY TRUE").executeUpdate()
                }
            }
    }

    private fun EntityManager.initTableNames() {
        tableNames = metamodel.managedTypes
            .mapNotNull { it.javaType.kotlin.findAnnotation<Table>() }
            .map { table -> table.name }
    }
}

• Using junit AfterEachCallback interface
• SET REFERENTIAL_INTEGRITY FALSE for better performance
• Get table names using Spring application context’s EntityManager and @Table annotations
• Bugfix/#33 test transaction by raeperd · Pull Request #39 · raeperd/realworld-springboot-kotlin

Usage

@ExtendWith(JpaDatabaseCleanerExtension::class)
@AutoConfigureMockMvc
@SpringBootTest
class ArticleFavoriteIntegrationTest(
    @Autowired private val mockMvc: MockMvc,
) {
    @Test
    fun `when post get delete articles favorite expect return valid response`() {
	    // testcodes
    }
}

• Just need to use @ExtendWith in class level
• This is much cleaner than implementing DatabaseCleanupService, and then inject dependency

Reference

1. Do not use transactional in tests
2. Cleaning up database tables after each integration test method with spring boot 2 and kotlin
3. Test case is not represents real applications transaction scope · Issue #33 · raeperd/realworld-springboot-kotlin
4. How To Clean Your Database Between JUnit 5 Tests With Spring Boot | Kotlin Tutorial - YouTube