upgrade to Spring Boot 4.2.1

CLAUDE.md

@@ -48,7 +48,7 @@ All production code lives under `de.hoennig.gittally`. Commands are in the `comm
 
 ## Testing Conventions
 
-Tests use **Kotest `FunSpec`** style. `SpringExtension` is registered globally in `KotestProjectConfig` — do not add it per-spec.
+Tests use **Kotest `FunSpec`** style. `SpringExtension` is registered globally in `io.kotest.provided.ProjectConfig` — do not add it per-spec.
 
 ```kotlin
 class MyTest : FunSpec() {
@@ -63,7 +63,21 @@ Use `shouldBe`, `shouldNotBe`, `shouldThrow` etc. from `io.kotest.matchers`.
 
 ### Mocking in Spring Slice Tests
 
-`springmockk` is not compatible with the target Spring Boot version (4.0). The `@MockkBean` annotation is unavailable. Use `@TestConfiguration` to register MockK mocks as Spring beans:
+Use `@MockkBean` from `springmockk` to inject MockK mocks into the Spring context:
+
+```kotlin
+@WebMvcTest(SomeController::class)
+class SomeControllerTest : FunSpec() {
+    @MockkBean
+    lateinit var someService: SomeService
+    init {
+        beforeEach { clearMocks(someService) }
+        // full MockK syntax: every { } / verify { }
+    }
+}
+```
+
+Alternatively, register mocks via `@TestConfiguration` without the springmockk dependency:
 
 ```kotlin
 @WebMvcTest(SomeController::class)
@@ -87,7 +101,5 @@ Pure unit tests (no Spring context) use MockK directly without any Spring wiring
 All major decisions are in `docs/adrs/`. Run `adr-status` (after `source .envrc`) for a one-line summary of each. Decisions in force:
 
 - **Test framework**: Kotest + MockK + WireMock + Testcontainers (ADR 0001)
-- **Gradle**: 8.14 target (currently 8.8; upgrade pending Spring Boot 4.0 migration) (ADR 0002)
+- **Gradle**: 8.14.5 (ADR 0002)
-- **Spring Boot**: 4.0 target (currently 3.3.4 — pending upgrade; 3.3.x is EOL) (ADR 0003)
+- **Spring Boot**: 4.0.6 (ADR 0003)
-
-The Spring Boot and Gradle upgrades are open work items documented in the ADRs. When upgrading, verify `ApplicationContextTest` passes as the primary smoke test.

build.gradle.kts

@@ -1,11 +1,11 @@
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 plugins {
-    id("org.springframework.boot") version "3.3.4"
+    id("org.springframework.boot") version "4.0.6"
-    id("io.spring.dependency-management") version "1.1.6"
+    id("io.spring.dependency-management") version "1.1.7"
-    id("org.jlleitschuh.gradle.ktlint") version "12.1.1"
+    id("org.jlleitschuh.gradle.ktlint") version "14.2.0"
-    kotlin("jvm") version "1.9.25"
+    kotlin("jvm") version "2.2.0"
-    kotlin("plugin.spring") version "1.9.25"
+    kotlin("plugin.spring") version "2.2.0"
 }
 
 group = "de.hoennig"
@@ -29,26 +29,26 @@ dependencies {
     testImplementation("org.springframework.boot:spring-boot-starter-test")
 
     // Kotest
-    testImplementation("io.kotest:kotest-runner-junit5:5.9.1")
+    testImplementation("io.kotest:kotest-runner-junit5:6.1.5")
-    testImplementation("io.kotest:kotest-assertions-core:5.9.1")
+    testImplementation("io.kotest:kotest-assertions-core:6.1.5")
-    testImplementation("io.kotest.extensions:kotest-extensions-spring:1.3.0")
+    testImplementation("io.kotest:kotest-extensions-spring:6.1.5")
 
     // MockK
     testImplementation("io.mockk:mockk:1.13.11")
-    testImplementation("com.ninja-squad:springmockk:4.0.2")
+    testImplementation("com.ninja-squad:springmockk:5.0.1")
 
     // WireMock
-    testImplementation("org.wiremock.integrations:wiremock-spring-boot:3.1.0")
+    testImplementation("org.wiremock.integrations:wiremock-spring-boot:4.2.1")
 
     // Testcontainers (versions managed by Spring Boot BOM)
     testImplementation("org.springframework.boot:spring-boot-testcontainers")
     testImplementation("org.testcontainers:testcontainers")
 }
 
-tasks.withType<KotlinCompile> {
+kotlin {
-    kotlinOptions {
+    compilerOptions {
-        freeCompilerArgs += "-Xjsr305=strict"
+        freeCompilerArgs.addAll("-Xjsr305=strict")
-        jvmTarget = "21"
+        jvmTarget = JvmTarget.JVM_21
     }
 }
 

docs/adrs/0002-2026-06-09.gradle-version.md

@@ -2,11 +2,11 @@
 
 **Status:**
 - proposed: 2026-06-09
-- accepted: -
+- accepted: 2026-06-09
 - rejected: -
 - superseded: -
 
-**Decision [proposed]:** Gradle 8.14 — minimum required by Spring Boot 4.0; Gradle 9 deferred until openapi-generator and ktlint-gradle confirm compatibility.
+**Decision [accepted]:** Gradle 8.14.5 — minimum required by Spring Boot 4.0; Gradle 9 deferred until openapi-generator and ktlint-gradle confirm compatibility.
 
 ## Context and Problem Statement
 
@@ -41,7 +41,7 @@ It has a direct dependency chain:
 - Plugin ecosystem readiness varies: the
   [openapi-generator Gradle plugin](https://github.com/OpenAPITools/openapi-generator/issues/22084)
   has a known Gradle 9 issue in its generated build files, and
-  [ktlint-gradle 12.1.1](https://github.com/JLLeitschuh/ktlint-gradle) Gradle 9 support
+  [ktlint-gradle 14.2.0](https://github.com/JLLeitschuh/ktlint-gradle) Gradle 9 support
   needs verification.
 - The [`io.spring.dependency-management` plugin](https://github.com/spring-gradle-plugins/dependency-management-plugin)
   used to resolve the Spring BOM has known friction with Gradle 9
@@ -56,9 +56,9 @@ current 8.8 is necessary regardless of whether Gradle 9 is chosen.
 * Gradle 8.14 (minimum for Spring Boot 4.0)
 * Gradle 9.x
 
-### [Gradle 8.x](https://docs.gradle.org/8.8/release-notes.html)
+### [Gradle 8.x](https://docs.gradle.org/8.14.5/release-notes.html)
 
-The currently configured series (wrapper at 8.8, to be bumped to 8.14+ for Spring Boot 4.0).
+The currently configured series (wrapper at 8.14.5, upgraded from 8.8 as part of the Spring Boot 4.0 migration).
 
 #### Advantages
 
@@ -91,7 +91,7 @@ The current major release (9.5.1 as of May 2026), officially supported alongside
 - [openapi-generator-gradle-plugin](https://github.com/OpenAPITools/openapi-generator/issues/22084)
   has a known Gradle 9 issue in generated `build.gradle` files; impact on the spec-first
   code generation task specifically needs verification.
-- [ktlint-gradle 12.1.1](https://github.com/JLLeitschuh/ktlint-gradle) Gradle 9 support
+- [ktlint-gradle 14.2.0](https://github.com/JLLeitschuh/ktlint-gradle) Gradle 9 support
   needs verification.
 - Configuration Cache mandatory means any currently uncached plugin will break the build
   until updated, complicating initial setup.
@@ -106,7 +106,7 @@ The main reasons:
 - Gradle 9 is technically compatible with Spring Boot 4.0, but the mandatory Configuration Cache
   creates unacceptable risk until the openapi-generator-gradle-plugin Gradle 9 compatibility
   is confirmed (see [issue #22084](https://github.com/OpenAPITools/openapi-generator/issues/22084)).
-- ktlint-gradle 12.1.1 Gradle 9 support is unverified; a formatter breaking the build on day
+- ktlint-gradle 14.2.0 Gradle 9 support is unverified; a formatter breaking the build on day
   one is a poor start.
 
 Upgrade trigger: revisit Gradle 9 once openapi-generator and ktlint-gradle confirm support.

docs/adrs/0003-2026-06-09.spring-boot-version.md

@@ -2,11 +2,11 @@
 
 **Status:**
 - proposed: 2026-06-09
-- accepted: -
+- accepted: 2026-06-09
 - rejected: -
 - superseded: -
 
-**Decision [proposed]:** Spring Boot 4.0 — only actively-supported version; springmockk workaround via @TestConfiguration until a compatible release is published.
+**Decision [accepted]:** Spring Boot 4.0.6 — only actively-supported version; springmockk 5.0.1 provides @MockkBean for Spring Boot 4.0.
 
 ## Context and Problem Statement
 
@@ -34,12 +34,12 @@ Spring Boot 4.0 moves to Spring Framework 7 and Jakarta EE 11.
 
 The key ecosystem dependencies and their Spring Boot 4.0 compatibility status:
 
-| Dependency | Role | Spring Boot 4.0 status |
+| Dependency | Version | Role | Spring Boot 4.0 status |
-|---|---|---|
+|---|---|---|---|
-| [picocli-spring-boot-starter](https://picocli.info/) | CLI wiring | Untested; last documented target is Spring Boot 3.1. The integration is minimal (one `IFactory` bean), so it likely works in practice. |
+| [picocli-spring-boot-starter](https://picocli.info/) | 4.7.6 | CLI wiring | **Compatible** — `ApplicationContextTest` confirms context wiring works. |
-| [springmockk](https://github.com/Ninja-Squad/springmockk) | `@MockkBean` in tests | **Incompatible** — confirmed Spring Boot 3.x only. |
+| [springmockk](https://github.com/Ninja-Squad/springmockk) | 5.0.1 | `@MockkBean` in tests | **Compatible** — 5.x released specifically for Spring Boot 4.0; `@MockkBean` verified. |
-| [kotest-extensions-spring](https://github.com/kotest/kotest-extensions-spring) | Kotest + `@SpringBootTest` | Compatibility unconfirmed. |
+| [kotest-extensions-spring](https://github.com/kotest/kotest-extensions-spring) | 6.1.5 | Kotest + `@SpringBootTest` | **Compatible** — 6.x (new groupId `io.kotest`) required; config moved to `io.kotest.provided.ProjectConfig`. |
-| [wiremock-spring-boot](https://wiremock.org/docs/spring-boot/) | HTTP stubbing in tests | **Compatible** — Spring Boot 4.0 explicitly supported since January 2026. |
+| [wiremock-spring-boot](https://wiremock.org/docs/spring-boot/) | 4.2.1 | HTTP stubbing in tests | **Compatible** — Spring Boot 4.0 explicitly supported since January 2026. |
 
 ## Considered Options
 
@@ -76,12 +76,9 @@ The current and only actively-supported major release.
 
 #### Disadvantages
 
-- **springmockk is incompatible.** The `@MockkBean` / `@SpykBean` annotations are not available.
+- **springmockk 5.x is required.** Version 4.x is Spring Boot 3.x only. Version 5.0.1 adds
-  This matters in particular for `@WebMvcTest` (controller error-behaviour) and
+  Spring Boot 4.0 support; `@MockkBean` / `@SpykBean` work as expected.
-  `@DataJpaTest`-adjacent tests where collaborators need to be mocked in the Spring context.
+  As an alternative, register MockK mocks via `@TestConfiguration` without the springmockk dependency:
-  The workaround is to register MockK mocks as Spring beans via `@TestConfiguration`,
-  which preserves full MockK syntax (`every { }`, `verify { }`) at the cost of one
-  inner configuration class per test file and an explicit `clearMocks()` call in `beforeEach`:
   ```kotlin
   @WebMvcTest(SomeController::class)
   @Import(SomeControllerTest.Mocks::class)
@@ -93,17 +90,12 @@ The current and only actively-supported major release.
       @Autowired lateinit var someService: SomeService
       init {
           beforeEach { clearMocks(someService) }
-          // full MockK syntax available
       }
   }
   ```
-  This is more verbose than `@MockkBean` but avoids mixing Mockito and MockK.
+- **picocli-spring-boot-starter** context wiring confirmed via `ApplicationContextTest`.
-  Revisit once springmockk publishes a Spring Boot 4.0-compatible release.
+- **kotest-extensions-spring 6.x** (groupId `io.kotest`) is required for Spring Boot 4.0.
-- **picocli-spring-boot-starter is untested against Spring Boot 4.0.**
+  The project config must be placed at `io.kotest.provided.ProjectConfig` (Kotest 6 discovery requirement).
-  The risk is low (the auto-configuration is a single `IFactory` bean with no framework-version-specific API),
-  but it cannot be assumed safe until verified by a running context test.
-- **kotest-extensions-spring** compatibility needs verification before the first
-  `@SpringBootTest` test is written.
 - Relatively new GA; fewer community examples for the 4.0 generation.
 
 ## Decision Outcome
@@ -124,9 +116,4 @@ The main reasons:
   - kotest-extensions-spring compatibility must be verified before the
     first `@SpringBootTest` test is written.
 
-Open items before the code is upgraded:
+All ecosystem blockers are resolved. The codebase runs Spring Boot 4.0.6.
-1. Bump Spring Boot to 4.0.6 and verify `ApplicationContextTest` still passes.
-2. Confirm picocli-spring-boot-starter works under the new context.
-3. Confirm kotest-extensions-spring works with Spring Boot 4.0.
-4. Replace `@MockkBean` usages with the `@TestConfiguration` + `mockk()` pattern
-   until springmockk publishes a compatible release.

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.5-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

src/main/kotlin/de/hoennig/gittally/GitTallyApplication.kt

@@ -17,7 +17,8 @@ class GitTallyApplication
 class CliRunner(
     private val factory: IFactory,
     private val rootCommand: GitTallyCommand,
-) : CommandLineRunner, ExitCodeGenerator {
+) : CommandLineRunner,
+    ExitCodeGenerator {
     private var exitCode = 0
 
     override fun run(vararg args: String) {

src/main/kotlin/de/hoennig/gittally/GitTallyCommand.kt

@@ -15,7 +15,5 @@ import picocli.CommandLine.Command
     description = ["Lightweight, declarative CI/CD system"],
 )
 class GitTallyCommand : Runnable {
-    override fun run() {
+    override fun run(): Unit = throw CommandLine.ParameterException(CommandLine(this), "Specify a subcommand")
-        throw CommandLine.ParameterException(CommandLine(this), "Specify a subcommand")
-    }
 }

src/test/kotlin/de/hoennig/gittally/KotestProjectConfig.kt

@@ -1,8 +0,0 @@
-package de.hoennig.gittally
-
-import io.kotest.core.config.AbstractProjectConfig
-import io.kotest.extensions.spring.SpringExtension
-
-object KotestProjectConfig : AbstractProjectConfig() {
-    override fun extensions() = listOf(SpringExtension)
-}

src/test/kotlin/de/hoennig/gittally/framework/MockKSmokeTest.kt

@@ -10,14 +10,15 @@ interface Greeter {
     fun greet(name: String): String
 }
 
-class MockKSmokeTest : FunSpec({
+class MockKSmokeTest :
+    FunSpec({
 
-    test("mockk stubs and verifies") {
+        test("mockk stubs and verifies") {
-        val greeter = mockk<Greeter>()
+            val greeter = mockk<Greeter>()
-        every { greeter.greet("world") } returns "hello, world"
+            every { greeter.greet("world") } returns "hello, world"
 
-        greeter.greet("world") shouldBe "hello, world"
+            greeter.greet("world") shouldBe "hello, world"
 
-        verify(exactly = 1) { greeter.greet("world") }
+            verify(exactly = 1) { greeter.greet("world") }
-    }
+        }
-})
+    })

src/test/kotlin/de/hoennig/gittally/framework/SpringMockKSmokeTest.kt

@@ -21,7 +21,6 @@ interface MessageService {
 @SpringBootTest
 @Import(SpringMockKSmokeTest.Mocks::class)
 class SpringMockKSmokeTest : FunSpec() {
-
     @TestConfiguration
     class Mocks {
         @Bean
@@ -47,7 +46,6 @@ class SpringMockKSmokeTest : FunSpec() {
 /** Verifies whether @MockkBean works with the current Spring Boot version (springmockk 4.0.2). */
 @SpringBootTest
 class MockkBeanSmokeTest : FunSpec() {
-
     @MockkBean
     lateinit var messageService: MessageService
 

src/test/kotlin/de/hoennig/gittally/framework/TestcontainersSmokeTest.kt

@@ -5,13 +5,15 @@ import io.kotest.matchers.shouldBe
 import org.testcontainers.containers.GenericContainer
 import org.testcontainers.utility.DockerImageName
 
-class TestcontainersSmokeTest : FunSpec({
+class TestcontainersSmokeTest :
+    FunSpec({
 
-    test("Testcontainers starts a container") {
+        test("Testcontainers starts a container") {
-        val container = GenericContainer(DockerImageName.parse("alpine:3"))
+            val container =
-            .withCommand("sh", "-c", "sleep 30")
+                GenericContainer(DockerImageName.parse("alpine:3"))
-        container.start()
+                    .withCommand("sh", "-c", "sleep 30")
-        container.isRunning shouldBe true
+            container.start()
-        container.stop()
+            container.isRunning shouldBe true
-    }
+            container.stop()
-})
+        }
+    })

src/test/kotlin/de/hoennig/gittally/framework/WireMockSmokeTest.kt

@@ -11,22 +11,24 @@ import java.net.http.HttpClient
 import java.net.http.HttpRequest
 import java.net.http.HttpResponse
 
-class WireMockSmokeTest : FunSpec({
+class WireMockSmokeTest :
+    FunSpec({
 
-    val server = WireMockServer(options().dynamicPort())
+        val server = WireMockServer(options().dynamicPort())
 
-    beforeSpec { server.start() }
+        beforeSpec { server.start() }
-    afterSpec { server.stop() }
+        afterSpec { server.stop() }
 
-    test("WireMock stubs an HTTP endpoint") {
+        test("WireMock stubs an HTTP endpoint") {
-        server.stubFor(get("/ping").willReturn(aResponse().withStatus(200).withBody("pong")))
+            server.stubFor(get("/ping").willReturn(aResponse().withStatus(200).withBody("pong")))
 
-        val response = HttpClient.newHttpClient().send(
+            val response =
-            HttpRequest.newBuilder().uri(URI.create("http://localhost:${server.port()}/ping")).build(),
+                HttpClient.newHttpClient().send(
-            HttpResponse.BodyHandlers.ofString(),
+                    HttpRequest.newBuilder().uri(URI.create("http://localhost:${server.port()}/ping")).build(),
-        )
+                    HttpResponse.BodyHandlers.ofString(),
+                )
 
-        response.statusCode() shouldBe 200
+            response.statusCode() shouldBe 200
-        response.body() shouldBe "pong"
+            response.body() shouldBe "pong"
-    }
+        }
-})
+    })

src/test/kotlin/io/kotest/provided/ProjectConfig.kt

@@ -0,0 +1,8 @@
+package io.kotest.provided
+
+import io.kotest.core.config.AbstractProjectConfig
+import io.kotest.extensions.spring.SpringExtension
+
+object ProjectConfig : AbstractProjectConfig() {
+    override val extensions = listOf(SpringExtension())
+}