feat(#821): ktor works with any dependency provider, and also with ktor-di with auto detection

Author: osoykan

build.gradle.kts

@@ -31,7 +31,10 @@ apiValidation {
     "spring-4x-kafka-tests",
     "spring-4x-tests",
     "spring-3x-tests",
-    "spring-2x-tests"
+    "spring-2x-tests",
+    "ktor-di-tests",
+    "ktor-koin-tests",
+    "ktor-test-fixtures",
   )
 }
 kover {

docs/release-notes/0.20.0.md

@@ -81,9 +81,54 @@ addInitializers(stoveSpring4xRegistrar { registerBean<MyService>() })
 
 ---
 
+### Ktor DI Flexibility
+
+Stove's Ktor module now supports multiple dependency injection systems. Previously, Koin was required. Now you can use:
+
+1. **Koin** (existing support)
+2. **Ktor-DI** (new built-in support)
+3. **Custom resolver** (any DI framework)
+
+Both Koin and Ktor-DI are now `compileOnly` dependencies - you bring your preferred DI system.
+
+**Using Koin:**
+
+```kotlin
+dependencies {
+    testImplementation("io.insert-koin:koin-ktor:$koinVersion")
+}
+
+// In your test setup
+bridge() // Auto-detects Koin
+```
+
+**Using Ktor-DI:**
+
+```kotlin
+dependencies {
+    testImplementation("io.ktor:ktor-server-di:$ktorVersion")
+}
+
+// In your test setup
+bridge() // Auto-detects Ktor-DI
+```
+
+**Using a Custom Resolver:**
+
+For any other DI framework (Kodein, Dagger, manual, etc.):
+
+```kotlin
+bridge { application, klass ->
+    // Your custom resolution logic
+    myDiContainer.resolve(klass.java)
+}
+```
+
+---
+
 ### Runtime Version Checks
 
-When Spring Boot or Spring Kafka is missing from the classpath, Stove now provides clear error messages:
+When Spring Boot, Spring Kafka, or Ktor DI is missing from the classpath, Stove now provides clear error messages:
 
 ```
 ═══════════════════════════════════════════════════════════════════════════════

gradle/libs.versions.toml

@@ -102,6 +102,7 @@ ktor-server-host-common = { module = "io.ktor:ktor-server-host-common", version.
 ktor-server = { module = "io.ktor:ktor-server", version.ref = "ktor" }
 ktor-server-call-logging = { module = "io.ktor:ktor-server-call-logging", version.ref = "ktor" }
 ktor-server-netty = { module = "io.ktor:ktor-server-netty", version.ref = "ktor" }
+ktor-server-di = { module = "io.ktor:ktor-server-di", version.ref = "ktor" }
 ktor-serialization-kotlinx-json = { module = "io.ktor:ktor-serialization-kotlinx-json", version.ref = "ktor" }
 ktor-client-core = { module = "io.ktor:ktor-client-core", version.ref = "ktor" }
 ktor-client-okhttp = { module = "io.ktor:ktor-client-okhttp", version.ref = "ktor" }

settings.gradle.kts

@@ -17,6 +17,9 @@ include(
 )
 include(
   "starters:ktor:stove-ktor-testing-e2e",
+  "starters:ktor:tests:ktor-test-fixtures",
+  "starters:ktor:tests:ktor-koin-tests",
+  "starters:ktor:tests:ktor-di-tests",
   "starters:spring:stove-spring-testing-e2e",
   "starters:spring:stove-spring-testing-e2e-kafka",
   "starters:spring:tests:spring-test-fixtures",

starters/ktor/stove-ktor-testing-e2e/api/stove-ktor-testing-e2e.api

@@ -1,3 +1,10 @@
+public final class com/trendyol/stove/testing/e2e/DependencyResolvers {
+	public static final field INSTANCE Lcom/trendyol/stove/testing/e2e/DependencyResolvers;
+	public final fun autoDetect ()Lkotlin/jvm/functions/Function2;
+	public final fun getKoin ()Lkotlin/jvm/functions/Function2;
+	public final fun getKtorDi ()Lkotlin/jvm/functions/Function2;
+}
+
 public final class com/trendyol/stove/testing/e2e/KtorApplicationUnderTest : com/trendyol/stove/testing/e2e/system/abstractions/ApplicationUnderTest {
 	public fun <init> (Lcom/trendyol/stove/testing/e2e/system/TestSystem;Lkotlin/jvm/functions/Function1;Ljava/util/List;)V
 	public fun start (Ljava/util/List;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -10,12 +17,19 @@ public final class com/trendyol/stove/testing/e2e/KtorApplicationUnderTestKt {
 }
 
 public final class com/trendyol/stove/testing/e2e/KtorBridgeSystem : com/trendyol/stove/testing/e2e/system/BridgeSystem, com/trendyol/stove/testing/e2e/system/abstractions/AfterRunAwareWithContext, com/trendyol/stove/testing/e2e/system/abstractions/PluggedSystem {
-	public fun <init> (Lcom/trendyol/stove/testing/e2e/system/TestSystem;)V
+	public fun <init> (Lcom/trendyol/stove/testing/e2e/system/TestSystem;Lkotlin/jvm/functions/Function2;)V
 	public fun get (Lkotlin/reflect/KClass;)Ljava/lang/Object;
 	public fun getTestSystem ()Lcom/trendyol/stove/testing/e2e/system/TestSystem;
 }
 
 public final class com/trendyol/stove/testing/e2e/KtorBridgeSystemKt {
-	public static final fun bridge-hQma78k (Lcom/trendyol/stove/testing/e2e/system/TestSystem;)Lcom/trendyol/stove/testing/e2e/system/TestSystem;
+	public static final fun bridge-PmNtuJU (Lcom/trendyol/stove/testing/e2e/system/TestSystem;Lkotlin/jvm/functions/Function2;)Lcom/trendyol/stove/testing/e2e/system/TestSystem;
+	public static synthetic fun bridge-PmNtuJU$default (Lcom/trendyol/stove/testing/e2e/system/TestSystem;Lkotlin/jvm/functions/Function2;ILjava/lang/Object;)Lcom/trendyol/stove/testing/e2e/system/TestSystem;
+}
+
+public final class com/trendyol/stove/testing/e2e/KtorDiCheck {
+	public static final field INSTANCE Lcom/trendyol/stove/testing/e2e/KtorDiCheck;
+	public final fun isKoinAvailable ()Z
+	public final fun isKtorDiAvailable ()Z
 }
 

starters/ktor/stove-ktor-testing-e2e/build.gradle.kts

@@ -1,5 +1,8 @@
 dependencies {
   api(projects.lib.stoveTestingE2e)
   implementation(libs.ktor.server.host.common)
-  implementation(libs.koin.ktor)
+  
+  // Both DI systems as compileOnly - users bring their preferred DI at runtime
+  compileOnly(libs.koin.ktor)
+  compileOnly(libs.ktor.server.di)
 }

starters/ktor/stove-ktor-testing-e2e/src/main/kotlin/com/trendyol/stove/testing/e2e/DependencyResolvers.kt

@@ -0,0 +1,55 @@
+package com.trendyol.stove.testing.e2e
+
+import io.ktor.server.application.*
+import io.ktor.server.plugins.di.*
+import io.ktor.util.reflect.*
+import org.koin.ktor.ext.getKoin
+import kotlin.reflect.KClass
+import kotlin.reflect.full.starProjectedType
+
+/**
+ * Type alias for a dependency resolver function.
+ * Takes an Application and a KClass, returns the resolved dependency.
+ */
+typealias DependencyResolver = (Application, KClass<*>) -> Any
+
+/**
+ * Default resolver implementations for supported DI frameworks.
+ */
+object DependencyResolvers {
+  /**
+   * Resolver for Koin DI framework.
+   */
+  val koin: DependencyResolver = { application, klass -> application.getKoin().get(klass) }
+
+  /**
+   * Resolver for Ktor-DI framework.
+   */
+  val ktorDi: DependencyResolver = { application, klass ->
+    require(application.attributes.contains(DependencyRegistryKey)) {
+      "Ktor-DI not installed in application. Make sure to install(DI) { ... } in your application."
+    }
+    val typeInfo = TypeInfo(klass, klass.starProjectedType)
+    application.dependencies.getBlocking(DependencyKey(type = typeInfo))
+  }
+
+  /**
+   * Auto-detects and returns the appropriate resolver based on available DI frameworks.
+   * Prefers Ktor-DI over Koin if both are available.
+   * Detection is deferred to runtime to ensure classpath is fully resolved.
+   */
+  fun autoDetect(): DependencyResolver = { application, klass ->
+    val resolver = when {
+      KtorDiCheck.isKtorDiAvailable() -> ktorDi
+
+      KtorDiCheck.isKoinAvailable() -> koin
+
+      else -> error(
+        "No supported DI framework found. " +
+          "Add either Koin (io.insert-koin:koin-ktor) or Ktor-DI (io.ktor:ktor-server-di) to your classpath, " +
+          "or provide a custom resolver via bridge(resolver = { app, klass -> ... })"
+      )
+    }
+    resolver(application, klass)
+  }
+}

starters/ktor/stove-ktor-testing-e2e/src/main/kotlin/com/trendyol/stove/testing/e2e/KtorBridgeSystem.kt

@@ -4,22 +4,47 @@ import com.trendyol.stove.testing.e2e.system.*
 import com.trendyol.stove.testing.e2e.system.abstractions.*
 import com.trendyol.stove.testing.e2e.system.annotations.StoveDsl
 import io.ktor.server.application.*
-import org.koin.ktor.ext.*
 import kotlin.reflect.KClass
 
 /**
  * A system that provides a bridge between the test system and the application context.
+ * Supports Koin, Ktor-DI, or a custom resolver for dependency resolution.
  *
  * @property testSystem the test system to bridge.
+ * @property resolver the dependency resolver function to use.
  */
 @StoveDsl
 class KtorBridgeSystem(
-  override val testSystem: TestSystem
+  override val testSystem: TestSystem,
+  private val resolver: DependencyResolver
 ) : BridgeSystem<Application>(testSystem),
   PluggedSystem,
   AfterRunAwareWithContext<Application> {
-  override fun <D : Any> get(klass: KClass<D>): D = ctx.getKoin().get(klass)
+  @Suppress("UNCHECKED_CAST")
+  override operator fun <D : Any> get(klass: KClass<D>): D = resolver(ctx, klass) as D
 }
 
+/**
+ * Registers the Ktor bridge system with automatic DI detection or a custom resolver.
+ * Supports Koin and Ktor-DI out of the box.
+ *
+ * Example usage with auto-detect:
+ * ```kotlin
+ * bridge() // Auto-detects Koin or Ktor-DI
+ * ```
+ *
+ * Example usage with custom resolver:
+ * ```kotlin
+ * bridge { application, klass ->
+ *   application.myCustomDi.resolve(klass)
+ * }
+ * ```
+ *
+ * @param resolver a function that takes an Application and KClass and returns the resolved dependency.
+ *                 Defaults to auto-detecting Koin or Ktor-DI.
+ * @throws IllegalStateException if no DI framework is available and no custom resolver is provided.
+ */
 @StoveDsl
-fun WithDsl.bridge(): TestSystem = this.testSystem.withBridgeSystem(KtorBridgeSystem(this.testSystem))
+fun WithDsl.bridge(
+  resolver: DependencyResolver = DependencyResolvers.autoDetect()
+): TestSystem = this.testSystem.withBridgeSystem(KtorBridgeSystem(this.testSystem, resolver))

starters/ktor/stove-ktor-testing-e2e/src/main/kotlin/com/trendyol/stove/testing/e2e/KtorDiCheck.kt

@@ -0,0 +1,28 @@
+@file:Suppress("TooGenericExceptionCaught", "SwallowedException")
+
+package com.trendyol.stove.testing.e2e
+
+/**
+ * Checks which DI system is available on the classpath.
+ */
+object KtorDiCheck {
+  /**
+   * Returns true if Koin is available on the classpath.
+   */
+  fun isKoinAvailable(): Boolean = try {
+    Class.forName("org.koin.ktor.ext.ApplicationExtKt")
+    true
+  } catch (_: ClassNotFoundException) {
+    false
+  }
+
+  /**
+   * Returns true if Ktor-DI is available on the classpath.
+   */
+  fun isKtorDiAvailable(): Boolean = try {
+    Class.forName("io.ktor.server.plugins.di.DependencyInjectionConfig")
+    true
+  } catch (_: ClassNotFoundException) {
+    false
+  }
+}