Kotest Integration

Module

db-tester-kotest

Extension Class

Location: io.github.seijikohara.dbtester.kotest.extension.DatabaseTestExtension

Type: TestCaseExtension - Intercepts test case execution for DataSet and ExpectedDataSet phases.

Registration

Recommended -- Use the @DatabaseTest annotation. The specification class must implement the DatabaseTestSupport interface:

@DatabaseTest
class UserRepositorySpec : AnnotationSpec(), DatabaseTestSupport {

    override val dbTesterRegistry = DataSourceRegistry()
    private lateinit var dataSource: DataSource

    @BeforeAll
    fun setupSpec() {
        dataSource = createDataSource()
        dbTesterRegistry.registerDefault(dataSource)
    }

    @Test
    @DataSet
    @ExpectedDataSet
    fun `should create user`() {
        // Test implementation
    }
}

Alternative -- Register the extension in the init block:

class UserRepositorySpec : AnnotationSpec(), DatabaseTestSupport {

    override val dbTesterRegistry = DataSourceRegistry()

    init {
        extensions(DatabaseTestExtension())
    }

    @BeforeAll
    fun setupSpec() {
        dbTesterRegistry.registerDefault(dataSource)
    }

    @Test
    @DataSet
    @ExpectedDataSet
    fun `should create user`() {
        // Test implementation
    }
}

DatabaseTestSupport Interface

The DatabaseTestSupport interface provides the contract for database testing:

Property	Type	Required	Description
dbTesterRegistry	DataSourceRegistry	Yes	Data source registration
dbTesterConfiguration	Configuration	No	Custom configuration (defaults to Configuration.defaults())

DataSource Registration

Implement the DatabaseTestSupport interface and override dbTesterRegistry:

@DatabaseTest
class UserRepositorySpec : AnnotationSpec(), DatabaseTestSupport {

    override val dbTesterRegistry = DataSourceRegistry()

    @BeforeAll
    fun setupSpec() {
        dbTesterRegistry.registerDefault(dataSource)
        dbTesterRegistry.register("secondary", secondaryDataSource)
    }
}

Configuration Customization

Override dbTesterConfiguration in the interface implementation:

@DatabaseTest
class UserRepositorySpec : AnnotationSpec(), DatabaseTestSupport {

    override val dbTesterRegistry = DataSourceRegistry()

    override val dbTesterConfiguration = Configuration.builder()
        .conventions(ConventionSettings.builder()
            .dataFormat(DataFormat.TSV)
            .build())
        .build()
}

Test Method Naming

Use backtick method names for descriptive test names:

@Test
@DataSet
fun `should create user with email`() {
    // Scenario name: "should create user with email"
}

AnnotationSpec Requirement

DB Tester requires AnnotationSpec style for Kotest integration for three reasons:

1. Annotations (@DataSet, @ExpectedDataSet) can apply to test methods
2. Method resolution via reflection is reliable
3. Familiar JUnit-like structure for Java developers

Related Specifications

• Test Frameworks Overview - Supported frameworks summary
• JUnit - JUnit integration
• Spock - Spock integration
• Spring Boot - Spring Boot auto-configuration
• Lifecycle - Lifecycle hooks and executor classes
• Annotations - Annotation details
• Configuration - Configuration options