Allow display name formatter to return null

kotest-extensions/kotest-extensions-junit5/src/jvmMain/kotlin/io/kotest/extensions/junit5/KotestExtensionContext.kt

@@ -4,7 +4,7 @@ import io.kotest.core.config.ProjectConfiguration
 import io.kotest.core.descriptors.toDescriptor
 import io.kotest.core.spec.Spec
 import io.kotest.core.test.TestCase
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.getFallbackDisplayNameFormatter
 import org.junit.jupiter.api.TestInstance
 import org.junit.jupiter.api.extension.ExtensionContext
 import org.junit.jupiter.api.extension.TestInstances
@@ -19,7 +19,7 @@ class KotestExtensionContext(
    private val testCase: TestCase?
 ) : ExtensionContext {
 
-   private val formatter = getDisplayNameFormatter(ProjectConfiguration().registry, ProjectConfiguration())
+   private val formatter = getFallbackDisplayNameFormatter(ProjectConfiguration().registry, ProjectConfiguration())
 
    override fun getExecutionMode(): ExecutionMode = ExecutionMode.CONCURRENT
 
@@ -103,7 +103,7 @@ class ExtensionStore(private val namespace: ExtensionContext.Namespace) : Extens
       key: K,
       defaultCreator: Function<K, V>,
       requiredType: Class<V>
-   ): V? {
+   ): V {
       val value = map[namespace to key]
       return when {
          value == null -> defaultCreator.apply(key)

kotest-extensions/kotest-extensions-junitxml/src/jvmMain/kotlin/io/kotest/extensions/junitxml/JunitXmlReporter.kt

@@ -8,7 +8,7 @@ import io.kotest.core.test.TestCase
 import io.kotest.core.test.TestResult
 import io.kotest.core.test.TestType
 import io.kotest.engine.test.names.formatTestPath
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.getFallbackDisplayNameFormatter
 import org.jdom2.Document
 import org.jdom2.Element
 import org.jdom2.output.Format
@@ -25,7 +25,6 @@ import java.time.format.DateTimeFormatter.ISO_LOCAL_DATE_TIME
 import java.util.concurrent.ConcurrentHashMap
 import kotlin.io.path.absolute
 import kotlin.reflect.KClass
-import kotlin.time.Duration
 import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.DurationUnit
 
@@ -58,7 +57,7 @@ class JunitXmlReporter(
       const val AttributeName = "name"
    }
 
-   private val formatter = getDisplayNameFormatter(ProjectConfiguration().registry, ProjectConfiguration())
+   private val formatter = getFallbackDisplayNameFormatter(ProjectConfiguration().registry, ProjectConfiguration())
    private var marks = ConcurrentHashMap<KClass<out Spec>, Long>()
 
    private fun outputDir(): Path {

kotest-framework/kotest-framework-api/src/commonMain/kotlin/io/kotest/core/config/ExtensionRegistry.kt

@@ -1,7 +1,9 @@
 package io.kotest.core.config
 
+import io.kotest.common.KotestInternal
 import io.kotest.core.extensions.Extension
 
+@KotestInternal
 interface ExtensionRegistry {
    fun all(): List<Extension>
    fun add(extension: Extension)
@@ -11,6 +13,7 @@ interface ExtensionRegistry {
    fun isNotEmpty(): Boolean
 }
 
+@KotestInternal
 class DefaultExtensionRegistry : ExtensionRegistry {
 
    private val extensions = mutableListOf<Extension>()
@@ -33,6 +36,7 @@ class DefaultExtensionRegistry : ExtensionRegistry {
    override fun isNotEmpty(): Boolean = extensions.isNotEmpty()
 }
 
+@KotestInternal
 object EmptyExtensionRegistry : ExtensionRegistry {
 
    override fun all(): List<Extension> = emptyList()
@@ -53,6 +57,7 @@ object EmptyExtensionRegistry : ExtensionRegistry {
    override fun isNotEmpty(): Boolean = false
 }
 
+@KotestInternal
 class FixedExtensionRegistry(private vararg val extensions: Extension) : ExtensionRegistry {
 
    override fun all(): List<Extension> = extensions.toList()

kotest-framework/kotest-framework-api/src/commonMain/kotlin/io/kotest/core/names/DisplayNameFormatter.kt

@@ -11,10 +11,10 @@ interface DisplayNameFormatter {
    /**
     * Returns a formatted name for a test.
     */
-   fun format(testCase: TestCase): String
+   fun format(testCase: TestCase): String?
 
    /**
     * Returns a formatted name for a spec class.
     */
-   fun format(kclass: KClass<*>): String
+   fun format(kclass: KClass<*>): String?
 }

kotest-framework/kotest-framework-engine/api/kotest-framework-engine.api

@@ -826,15 +826,31 @@ public final class io/kotest/engine/test/names/DefaultDisplayNameFormatter : io/
 
 public final class io/kotest/engine/test/names/DefaultDisplayNameFormatterKt {
 	public static final fun appendTagsInDisplayName (Lio/kotest/core/test/TestCase;Ljava/lang/String;)Ljava/lang/String;
-	public static final fun getDisplayNameFormatter (Lio/kotest/core/config/ExtensionRegistry;Lio/kotest/core/config/ProjectConfiguration;)Lio/kotest/core/names/DisplayNameFormatter;
 }
 
 public final class io/kotest/engine/test/names/DuplicateTestNameException : java/lang/RuntimeException {
 	public fun <init> (Ljava/lang/String;)V
 }
 
+public final class io/kotest/engine/test/names/FallbackDisplayNameFormatter {
+	public static final field Companion Lio/kotest/engine/test/names/FallbackDisplayNameFormatter$Companion;
+	public fun <init> (Lio/kotest/core/names/DisplayNameFormatter;Lio/kotest/engine/test/names/DefaultDisplayNameFormatter;)V
+	public fun <init> (Lio/kotest/engine/test/names/DefaultDisplayNameFormatter;)V
+	public final fun format (Lio/kotest/core/test/TestCase;)Ljava/lang/String;
+	public final fun format (Lkotlin/reflect/KClass;)Ljava/lang/String;
+}
+
+public final class io/kotest/engine/test/names/FallbackDisplayNameFormatter$Companion {
+	public final fun default ()Lio/kotest/engine/test/names/FallbackDisplayNameFormatter;
+	public final fun default (Lio/kotest/core/config/ProjectConfiguration;)Lio/kotest/engine/test/names/FallbackDisplayNameFormatter;
+}
+
+public final class io/kotest/engine/test/names/GetDisplayNameFormatterKt {
+	public static final fun getFallbackDisplayNameFormatter (Lio/kotest/core/config/ExtensionRegistry;Lio/kotest/core/config/ProjectConfiguration;)Lio/kotest/engine/test/names/FallbackDisplayNameFormatter;
+}
+
 public final class io/kotest/engine/test/names/PathsKt {
-	public static final fun formatTestPath (Lio/kotest/core/names/DisplayNameFormatter;Lio/kotest/core/test/TestCase;Ljava/lang/String;)Ljava/lang/String;
+	public static final fun formatTestPath (Lio/kotest/engine/test/names/FallbackDisplayNameFormatter;Lio/kotest/core/test/TestCase;Ljava/lang/String;)Ljava/lang/String;
 }
 
 public final class io/kotest/engine/test/scopes/DuplicateNameHandlingTestScope : io/kotest/core/test/TestScope {

kotest-framework/kotest-framework-engine/src/commonMain/kotlin/io/kotest/engine/listener/TeamCityTestEngineListener.kt

@@ -1,9 +1,9 @@
 package io.kotest.engine.listener
 
+import io.kotest.common.KotestInternal
 import io.kotest.core.config.ProjectConfiguration
 import io.kotest.core.descriptors.Descriptor
 import io.kotest.core.descriptors.toDescriptor
-import io.kotest.core.names.DisplayNameFormatter
 import io.kotest.core.test.TestCase
 import io.kotest.core.test.TestResult
 import io.kotest.core.test.TestType
@@ -12,23 +12,24 @@ import io.kotest.engine.extensions.MultipleExceptions
 import io.kotest.engine.interceptors.EngineContext
 import io.kotest.engine.teamcity.Locations
 import io.kotest.engine.teamcity.TeamCityMessageBuilder
-import io.kotest.engine.test.names.DefaultDisplayNameFormatter
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.FallbackDisplayNameFormatter
+import io.kotest.engine.test.names.getFallbackDisplayNameFormatter
 import io.kotest.mpp.Logger
 import io.kotest.mpp.bestName
 import kotlin.reflect.KClass
 
 /**
  * A [TestEngineListener] that logs events to the console using a [TeamCityMessageBuilder].
  */
+@KotestInternal
 class TeamCityTestEngineListener(
    private val prefix: String = TeamCityMessageBuilder.TeamCityPrefix,
    private val details: Boolean = true,
 ) : TestEngineListener {
 
    private val logger = Logger(TeamCityTestEngineListener::class)
 
-   private var formatter: DisplayNameFormatter = DefaultDisplayNameFormatter(ProjectConfiguration())
+   private var formatter = FallbackDisplayNameFormatter.default(ProjectConfiguration())
 
    // once a spec has completed, we want to be able to check whether any given test is
    // a container or a leaf test, and so this map contains all test that have children
@@ -73,7 +74,7 @@ class TeamCityTestEngineListener(
    override suspend fun engineStarted() {}
 
    override suspend fun engineInitialized(context: EngineContext) {
-      formatter = getDisplayNameFormatter(context.configuration.registry, context.configuration)
+      formatter = getFallbackDisplayNameFormatter(context.configuration.registry, context.configuration)
    }
 
    override suspend fun engineFinished(t: List<Throwable>) {

kotest-framework/kotest-framework-engine/src/commonMain/kotlin/io/kotest/engine/test/names/DefaultDisplayNameFormatter.kt

@@ -3,9 +3,7 @@ package io.kotest.engine.test.names
 import io.kotest.common.Platform
 import io.kotest.common.platform
 import io.kotest.core.annotation.displayname.wrapper
-import io.kotest.core.config.ExtensionRegistry
 import io.kotest.core.config.ProjectConfiguration
-import io.kotest.core.extensions.DisplayNameFormatterExtension
 import io.kotest.core.names.DisplayNameFormatter
 import io.kotest.core.names.TestNameCase
 import io.kotest.core.spec.DisplayName
@@ -14,13 +12,6 @@ import io.kotest.mpp.annotation
 import io.kotest.mpp.bestName
 import kotlin.reflect.KClass
 
-fun getDisplayNameFormatter(registry: ExtensionRegistry, configuration: ProjectConfiguration): DisplayNameFormatter {
-   return registry.all()
-      .filterIsInstance<DisplayNameFormatterExtension>()
-      .firstOrNull()
-      ?.formatter() ?: DefaultDisplayNameFormatter(configuration)
-}
-
 /**
  * A default implementation of [DisplayNameFormatter].
  * Used when there are no registered [io.kotest.core.extensions.DisplayNameFormatterExtension]s.

kotest-framework/kotest-framework-engine/src/commonMain/kotlin/io/kotest/engine/test/names/FallbackDisplayNameFormatter.kt

@@ -0,0 +1,29 @@
+package io.kotest.engine.test.names
+
+import io.kotest.core.config.ProjectConfiguration
+import io.kotest.core.names.DisplayNameFormatter
+import io.kotest.core.test.TestCase
+import kotlin.reflect.KClass
+
+class FallbackDisplayNameFormatter(
+   private val custom: DisplayNameFormatter?,
+   private val fallback: DefaultDisplayNameFormatter,
+) {
+
+   companion object {
+      fun default() = default(ProjectConfiguration())
+
+      fun default(configuration: ProjectConfiguration) =
+         FallbackDisplayNameFormatter(DefaultDisplayNameFormatter(configuration))
+   }
+
+   constructor(fallback: DefaultDisplayNameFormatter) : this(null, fallback)
+
+   fun format(kclass: KClass<*>): String {
+      return custom?.format(kclass) ?: fallback.format(kclass)
+   }
+
+   fun format(testCase: TestCase): String {
+      return custom?.format(testCase) ?: fallback.format(testCase)
+   }
+}

kotest-framework/kotest-framework-engine/src/commonMain/kotlin/io/kotest/engine/test/names/GetDisplayNameFormatter.kt

@@ -0,0 +1,17 @@
+package io.kotest.engine.test.names
+
+import io.kotest.common.KotestInternal
+import io.kotest.core.config.ExtensionRegistry
+import io.kotest.core.config.ProjectConfiguration
+import io.kotest.core.extensions.DisplayNameFormatterExtension
+
+@KotestInternal
+fun getFallbackDisplayNameFormatter(
+   registry: ExtensionRegistry,
+   configuration: ProjectConfiguration,
+): FallbackDisplayNameFormatter {
+   val custom = registry.all()
+      .filterIsInstance<DisplayNameFormatterExtension>()
+      .firstOrNull()?.formatter()
+   return FallbackDisplayNameFormatter(custom, DefaultDisplayNameFormatter(configuration))
+}

kotest-framework/kotest-framework-engine/src/commonMain/kotlin/io/kotest/engine/test/names/paths.kt

@@ -1,9 +1,8 @@
 package io.kotest.engine.test.names
 
-import io.kotest.core.names.DisplayNameFormatter
 import io.kotest.core.test.TestCase
 
-fun DisplayNameFormatter.formatTestPath(testCase: TestCase, separator: String): String {
+fun FallbackDisplayNameFormatter.formatTestPath(testCase: TestCase, separator: String): String {
    return when (val parent = testCase.parent) {
       null -> format(testCase)
       else -> formatTestPath(parent, separator) + separator + format(testCase)

kotest-framework/kotest-framework-engine/src/jsMain/kotlin/io/kotest/engine/spec/createSpecExecutorDelegate.kt

@@ -12,7 +12,7 @@ import io.kotest.engine.interceptors.EngineContext
 import io.kotest.engine.it
 import io.kotest.engine.test.TestCaseExecutor
 import io.kotest.engine.test.interceptors.testNameEscape
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.getFallbackDisplayNameFormatter
 import io.kotest.engine.test.scopes.TerminalTestScope
 import io.kotest.engine.test.status.isEnabledInternal
 import io.kotest.engine.xit
@@ -32,7 +32,7 @@ internal actual fun createSpecExecutorDelegate(
 @ExperimentalKotest
 internal class JavascriptSpecExecutorDelegate(private val context: EngineContext) : SpecExecutorDelegate {
 
-   private val formatter = getDisplayNameFormatter(
+   private val formatter = getFallbackDisplayNameFormatter(
       context.configuration.registry,
       context.configuration,
    )

kotest-framework/kotest-framework-engine/src/jvmMain/kotlin/io/kotest/engine/listener/EnhancedConsoleTestEngineListener.kt

@@ -4,14 +4,13 @@ import com.github.ajalt.mordant.TermColors
 import io.kotest.core.config.ProjectConfiguration
 import io.kotest.core.descriptors.Descriptor
 import io.kotest.core.descriptors.toDescriptor
-import io.kotest.core.names.DisplayNameFormatter
 import io.kotest.core.test.TestCase
 import io.kotest.core.test.TestResult
 import io.kotest.core.test.TestType
 import io.kotest.engine.interceptors.EngineContext
-import io.kotest.engine.test.names.DefaultDisplayNameFormatter
+import io.kotest.engine.test.names.FallbackDisplayNameFormatter
 import io.kotest.engine.test.names.formatTestPath
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.getFallbackDisplayNameFormatter
 import kotlin.reflect.KClass
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.milliseconds
@@ -32,7 +31,7 @@ class EnhancedConsoleTestEngineListener(private val term: TermColors) : Abstract
    private var slow = 500.milliseconds
    private var verySlow = 5000.milliseconds
 
-   private var formatter:DisplayNameFormatter = DefaultDisplayNameFormatter(ProjectConfiguration())
+   private var formatter = FallbackDisplayNameFormatter.default(ProjectConfiguration())
 
    private fun green(str: String) = term.green(str)
    private fun greenBold(str: String) = term.green.plus(term.bold).invoke(str)
@@ -75,7 +74,7 @@ class EnhancedConsoleTestEngineListener(private val term: TermColors) : Abstract
 
    override suspend fun engineInitialized(context: EngineContext) {
 
-      formatter = getDisplayNameFormatter(context.configuration.registry, context.configuration)
+      formatter = getFallbackDisplayNameFormatter(context.configuration.registry, context.configuration)
 
       println(bold(">> Kotest"))
       println("- " + intros.shuffled().first())
@@ -209,6 +208,7 @@ class EnhancedConsoleTestEngineListener(private val term: TermColors) : Abstract
             testsFailed = testsFailed + Pair(testCase, result)
             specsFailed = specsFailed + testCase.descriptor.spec()
          }
+
          else -> Unit
       }
 

kotest-runner/kotest-runner-junit5/api/kotest-runner-junit5.api

@@ -4,7 +4,7 @@ public final class io/kotest/runner/junit/platform/DescriptorsKt {
 }
 
 public final class io/kotest/runner/junit/platform/JUnitTestEngineListener : io/kotest/engine/listener/AbstractTestEngineListener {
-	public fun <init> (Lorg/junit/platform/engine/EngineExecutionListener;Lorg/junit/platform/engine/support/descriptor/EngineDescriptor;Lio/kotest/core/names/DisplayNameFormatter;)V
+	public fun <init> (Lorg/junit/platform/engine/EngineExecutionListener;Lorg/junit/platform/engine/support/descriptor/EngineDescriptor;Lio/kotest/engine/test/names/FallbackDisplayNameFormatter;)V
 	public fun engineFinished (Ljava/util/List;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun engineInitialized (Lio/kotest/engine/interceptors/EngineContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun engineStarted (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -27,7 +27,6 @@ public final class io/kotest/runner/junit/platform/KotestEngineDescriptor : org/
 
 public final class io/kotest/runner/junit/platform/KotestJunitPlatformTestEngine : org/junit/platform/engine/TestEngine {
 	public static final field Companion Lio/kotest/runner/junit/platform/KotestJunitPlatformTestEngine$Companion;
-	public static final field EngineId Ljava/lang/String;
 	public fun <init> ()V
 	public fun discover (Lorg/junit/platform/engine/EngineDiscoveryRequest;Lorg/junit/platform/engine/UniqueId;)Lio/kotest/runner/junit/platform/KotestEngineDescriptor;
 	public synthetic fun discover (Lorg/junit/platform/engine/EngineDiscoveryRequest;Lorg/junit/platform/engine/UniqueId;)Lorg/junit/platform/engine/TestDescriptor;

kotest-runner/kotest-runner-junit5/src/jvmMain/kotlin/io/kotest/runner/junit/platform/JUnitTestEngineListener.kt

@@ -12,8 +12,7 @@ import io.kotest.core.test.TestType
 import io.kotest.engine.errors.ExtensionExceptionExtractor
 import io.kotest.engine.interceptors.EngineContext
 import io.kotest.engine.listener.AbstractTestEngineListener
-import io.kotest.engine.test.names.DefaultDisplayNameFormatter
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.FallbackDisplayNameFormatter
 import io.kotest.mpp.Logger
 import io.kotest.mpp.bestName
 import org.junit.platform.engine.EngineExecutionListener
@@ -75,7 +74,7 @@ import kotlin.time.Duration
 class JUnitTestEngineListener(
    private val listener: EngineExecutionListener,
    val root: EngineDescriptor,
-   private val formatter: DisplayNameFormatter,
+   private val formatter: FallbackDisplayNameFormatter,
 ) : AbstractTestEngineListener() {
 
    private val logger = Logger(JUnitTestEngineListener::class)

kotest-runner/kotest-runner-junit5/src/jvmMain/kotlin/io/kotest/runner/junit/platform/KotestJunitPlatformTestEngine.kt

@@ -4,15 +4,15 @@ import io.kotest.core.config.ProjectConfiguration
 import io.kotest.core.descriptors.toDescriptor
 import io.kotest.core.extensions.Extension
 import io.kotest.core.filter.TestFilter
-import io.kotest.core.names.DisplayNameFormatter
 import io.kotest.core.spec.Spec
 import io.kotest.engine.TestEngineLauncher
 import io.kotest.engine.config.ConfigManager
 import io.kotest.engine.config.detectAbstractProjectConfigsJVM
 import io.kotest.engine.config.loadProjectConfigFromClassnameJVM
 import io.kotest.engine.listener.PinnedSpecTestEngineListener
 import io.kotest.engine.listener.ThreadSafeTestEngineListener
-import io.kotest.engine.test.names.getDisplayNameFormatter
+import io.kotest.engine.test.names.FallbackDisplayNameFormatter
+import io.kotest.engine.test.names.getFallbackDisplayNameFormatter
 import io.kotest.framework.discovery.Discovery
 import io.kotest.framework.discovery.DiscoveryRequest
 import io.kotest.mpp.Logger
@@ -41,7 +41,7 @@ class KotestJunitPlatformTestEngine : TestEngine {
    private val logger = Logger(KotestJunitPlatformTestEngine::class)
 
    companion object {
-      const val EngineId = "kotest"
+      internal const val EngineId = "kotest"
    }
 
    override fun getId(): String = EngineId
@@ -169,8 +169,8 @@ class KotestEngineDescriptor(
    val error: Throwable?, // an error during discovery
 ) : EngineDescriptor(id, "Kotest") {
 
-   internal val formatter: DisplayNameFormatter by lazy {
-      getDisplayNameFormatter(configuration.registry, configuration)
+   internal val formatter: FallbackDisplayNameFormatter by lazy {
+      getFallbackDisplayNameFormatter(configuration.registry, configuration)
    }
 
    internal val classes: List<KClass<out Spec>>