[#337] Automatically add junit-platform-launcher to testRuntimeOnly

... for JUnit Platform projects to avoid "UNKNOWN_ERROR" or:
"NoClassDefFoundError: org.junit.platform.launcher.core.LauncherFactory" with PIT 1.14.0+
(with pitest-junit-plugin 1.2.0+).

That dependency is no longer shaded. More details:
#337

Author: szpak

CHANGELOG.md

@@ -2,9 +2,18 @@
 
 ## 1.14.0 - Unreleased
 
- - Remove deprecated Project.getConvention() usage (in Gradle 8.2+) - [#343](https://github.com/szpak/gradle-pitest-plugin/issues/343)
+ - Automatically add `junit-platform-launcher` dependency to `testRuntimeOnly` for JUnit Platform projects - [#337](https://github.com/szpak/gradle-pitest-plugin/issues/337) - help from [Björn Kautler](https://github.com/Vampire)
+ - Remove deprecated `Project.getConvention()` usage (in Gradle 8.2+) - [#343](https://github.com/szpak/gradle-pitest-plugin/issues/343)
  - Basic regression testing with Gradle up to 8.2
 
+**Compatibility notes**
+Starting with PIT 1.14.0 (with pitest-junit-plugin 1.2.0+) `junit-platform-launcher` is no longer shaded and has to be explicitly added to avoid:
+"Minion exited abnormally due to UNKNOWN_ERROR" or "NoClassDefFoundError: org.junit.platform.launcher.core.LauncherFactory".
+
+As an experimental (incubating) feature, `junit-platform-launcher` is automatically added to the `testRuntimeOnly` configuration for the JUnit Platform projects.
+
+**PLEASE NOTE**. This feature is experimental and might not work as expected in some corner cases. In that situation, just disable it with `addJUnitPlatformLauncher = false` and add the required dependency 'junit-platform-launcher' in a proper version to 'testRuntimeOnly' manually. More information: https://github.com/szpak/gradle-pitest-plugin/issues/337
+
 
 ## 1.9.11 - 2022-11-27
 

src/funcTest/groovy/info/solidsoft/gradle/pitest/functional/Junit5FunctionalSpec.groovy

@@ -33,7 +33,8 @@ class Junit5FunctionalSpec extends AbstractPitestFunctionalSpec {
             result.standardOutput.contains('Generated 2 mutations Killed 2 (100%)')
     }
 
-    @Issue(["https://github.com/szpak/gradle-pitest-plugin/issues/177", "https://github.com/szpak/gradle-pitest-plugin/issues/300"])
+    @Issue(["https://github.com/szpak/gradle-pitest-plugin/issues/177", "https://github.com/szpak/gradle-pitest-plugin/issues/300",
+        "https://github.com/szpak/gradle-pitest-plugin/issues/337"])
     void "should work with junit5 without explicitly adding dependency (#description)"() {
         given:
             copyResources("testProjects/junit5simple", "")
@@ -51,7 +52,8 @@ class Junit5FunctionalSpec extends AbstractPitestFunctionalSpec {
             result.standardOutput.contains("junit-platform-commons-${expectedJUnitPlatformVersion}.jar")
         where:
             buildFileName                             || expectedJunitPluginVersion | expectedJUnitJupiterVersion | expectedJUnitPlatformVersion
-            'build.gradle'                            || "1.0.0"                    | "5.8.0"                     | "1.8.0"
+            'build.gradle'                            || "1.2.0"                    | "5.10.0"                    | "1.10.0"
+            'build-pit-plugin-1.0.0-junit-5.8.gradle' || "1.0.0"                    | "5.8.0"                     | "1.8.0"
             'build-pit-1.8-junit-platform-5.7.gradle' || "0.14"                     | "5.7.0"                     | "1.7.0"
 
             description = "plugin $expectedJunitPluginVersion, junit $expectedJUnitJupiterVersion, platform $expectedJUnitPlatformVersion"

src/funcTest/resources/testProjects/junit5kotlin/build.gradle

@@ -1,7 +1,7 @@
 buildscript {
     ext.kotlin_version = '1.3.61'
-    ext.junit5Version = '5.7.0'
-    ext.junitPlatformVersion = '1.7.0'
+    ext.junit5Version = '5.10.0'
+    ext.junitPlatformVersion = '1.10.0'
 
     repositories {
         mavenCentral()
@@ -31,7 +31,7 @@ dependencies {
     testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junit5Version"
     testImplementation "org.junit.platform:junit-platform-runner:$junitPlatformVersion"
 
-    pitest 'org.pitest:pitest-junit5-plugin:1.0.0'
+    pitest 'org.pitest:pitest-junit5-plugin:1.2.0'
 }
 
 compileKotlin {

src/funcTest/resources/testProjects/junit5simple/build-pit-plugin-1.0.0-junit-5.8.gradle

@@ -0,0 +1,33 @@
+apply plugin: 'java'
+apply plugin: 'info.solidsoft.pitest'
+
+/*
+//Local/current version of the plugin should be put on a classpath earlier to override that plugin version
+buildscript {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+    }
+    dependencies {
+        classpath 'info.solidsoft.gradle.pitest:gradle-pitest-plugin:X.Y.Z-SNAPSHOT'
+    }
+}
+*/
+
+repositories {
+    mavenCentral()
+}
+
+group = "pitest.test"
+
+dependencies {
+    testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.8.0'
+}
+
+test {
+    useJUnitPlatform()
+}
+
+pitest {
+    junit5PluginVersion = "1.0.0"
+}

src/funcTest/resources/testProjects/junit5simple/build.gradle

@@ -18,21 +18,18 @@ repositories {
     mavenCentral()
 }
 
-dependencies {
-//    //Not needed, 'junit5PluginVersion' should implicitly add it in requested version
-//    pitest 'org.pitest:pitest-junit5-plugin:1.0.0'
-}
-
 group = "pitest.test"
 
 dependencies {
-    testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.8.0'
+    testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.10.0'
 }
 
 test {
     useJUnitPlatform()
 }
 
 pitest {
-    junit5PluginVersion = "1.0.0"
+    pitestVersion = "1.14.4"
+    junit5PluginVersion = "1.2.0"    //with no longer shaded junit-platform-launcher
+    verbose = true  //for "ClassNotFoundException: org.junit.platform.launcher.core.LauncherFactory" which should not happen
 }

src/main/groovy/info/solidsoft/gradle/pitest/PitestPlugin.groovy

@@ -23,6 +23,9 @@ import org.gradle.api.GradleException
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.artifacts.Configuration
+import org.gradle.api.artifacts.ModuleVersionIdentifier
+import org.gradle.api.artifacts.result.ResolutionResult
+import org.gradle.api.artifacts.result.ResolvedComponentResult
 import org.gradle.api.file.FileCollection
 import org.gradle.api.logging.Logger
 import org.gradle.api.logging.Logging
@@ -112,6 +115,7 @@ class PitestPlugin implements Plugin<Project> {
         extension.fileExtensionsToFilter.set(DEFAULT_FILE_EXTENSIONS_TO_FILTER_FROM_CLASSPATH)
         extension.useClasspathFile.set(false)
         extension.verbosity.set("NO_SPINNER")
+        extension.addJUnitPlatformLauncher.set(true)
     }
 
     private void failWithMeaningfulErrorMessageOnUnsupportedConfigurationInRootProjectBuildScript() {
@@ -239,6 +243,52 @@ class PitestPlugin implements Plugin<Project> {
                 dependencies.add(project.dependencies.create(junit5PluginDependencyAsString))
             }
         }
+
+        addJUnitPlatformLauncherDependencyIfNeeded()
+    }
+
+    private void addJUnitPlatformLauncherDependencyIfNeeded() {
+        Configuration testImplementation = project.configurations.findByName("testImplementation")
+        testImplementation.withDependencies { directDependencies ->
+            if (!extension.addJUnitPlatformLauncher.isPresent() || !extension.addJUnitPlatformLauncher.get()) {
+                log.info("'addJUnitPlatformLauncher' feature explicitly disabled in configuration. " +
+                    "Add junit-platform-launcher manually or expect 'Minion exited abnormally due to UNKNOWN_ERROR' or 'NoClassDefFoundError'")
+                return
+            }
+
+            //Note: For simplicity, adding also for older pitest-junit5-plugin versions (<1.2.0), which is not needed
+
+            final String orgJUnitPlatformGroup = "org.junit.platform"
+
+            log.debug("Direct ${testImplementation.name} dependencies (${directDependencies.size()}): ${directDependencies}")
+
+            //copy() seems to copy also something that refers to original configuration and generates StackOverflow on getting components
+            Configuration tmpTestImplementation = project.configurations.maybeCreate("tmpTestImplementation")
+            directDependencies.each { directDependency ->
+                tmpTestImplementation.dependencies.add(directDependency)
+            }
+
+            ResolutionResult resolutionResult = tmpTestImplementation.incoming.resolutionResult
+            Set<ResolvedComponentResult> allResolvedComponents = resolutionResult.allComponents
+            log.debug("All resolved components ${testImplementation.name} (${allResolvedComponents.size()}): ${allResolvedComponents}")
+
+            ResolvedComponentResult foundJunitPlatformComponent = allResolvedComponents.find { ResolvedComponentResult componentResult ->
+                ModuleVersionIdentifier moduleVersion = componentResult.moduleVersion
+                return moduleVersion.group == orgJUnitPlatformGroup &&
+                    (moduleVersion.name == "junit-platform-engine" || moduleVersion.name == "junit-platform-commons")
+            }
+
+            if (!foundJunitPlatformComponent) {
+                log.info("No ${orgJUnitPlatformGroup} components founds in ${testImplementation.name}, junit-platform-launcher will not be added")
+                return
+            }
+
+            String junitPlatformLauncherDependencyAsString = "${orgJUnitPlatformGroup}:junit-platform-launcher:${foundJunitPlatformComponent.moduleVersion.version}"
+            log.info("${orgJUnitPlatformGroup} component (${foundJunitPlatformComponent}) found in ${testImplementation.name}, " +
+                "adding junit-platform-launcher (${junitPlatformLauncherDependencyAsString}) to testRuntimeOnly")
+            project.configurations.findByName("testRuntimeOnly").dependencies.add(
+                project.dependencies.create(junitPlatformLauncherDependencyAsString))
+        }
     }
 
     private void suppressPassingDeprecatedTestPluginForNewerPitVersions(PitestTask pitestTask) {

src/main/groovy/info/solidsoft/gradle/pitest/PitestPluginExtension.groovy

@@ -250,6 +250,23 @@ class PitestPluginExtension {
     @Incubating
     final ListProperty<String> fileExtensionsToFilter
 
+    /**
+     * Adds 'junit-platform-launcher' automatically to the 'testRuntimeOnly' configuration.
+     *
+     * Starting with PIT 1.14.0 (with pitest-junit-plugin 1.2.0+) that dependency is no longer shaded and has to be explicitly added to avoid:
+     * "Minion exited abnormally due to UNKNOWN_ERROR" or "NoClassDefFoundError: org.junit.platform.launcher.core.LauncherFactory".
+     * This feature is enabled by default if junit-platform is found on the testImplementation classes.
+     *
+     * PLEASE NOTE. This feature is experimental and might not work as expected in some corner cases. In that situation, just disable it and add
+     * required dependency 'junit-platform-launcher' in a proper version to 'testRuntimeOnly' manually.
+     *
+     * More information: https://github.com/szpak/gradle-pitest-plugin/issues/337
+     *
+     * @since 1.14.0
+     */
+    @Incubating
+    final Property<Boolean> addJUnitPlatformLauncher
+
     final ReportAggregatorProperties reportAggregatorProperties
 
     PitestPluginExtension(Project project) {
@@ -303,6 +320,7 @@ class PitestPluginExtension {
         outputCharset = of.property(Charset)
         features = nullListPropertyOf(p, String)
         fileExtensionsToFilter = nullListPropertyOf(p, String)
+        addJUnitPlatformLauncher = of.property(Boolean)
         reportAggregatorProperties = new ReportAggregatorProperties(of)
     }