Propagate Java toolchain to JavaExec tasks

grails-gradle/plugins/build.gradle

@@ -56,6 +56,16 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-gradle-plugin'
     implementation 'org.springframework.boot:spring-boot-loader-tools'
     implementation 'io.spring.gradle:dependency-management-plugin'
+
+    // Testing - Gradle TestKit is auto-added by java-gradle-plugin
+    testImplementation('org.spockframework:spock-core') { transitive = false }
+    testImplementation 'org.codehaus.groovy:groovy-test-junit5'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
+}
+
+configurations {
+    testCompileClasspath.exclude group: 'org.apache.groovy', module: 'groovy'
+    testRuntimeClasspath.exclude group: 'org.apache.groovy', module: 'groovy'
 }
 
 gradlePlugin {
@@ -129,6 +139,12 @@ tasks.withType(Copy) {
     }
 }
 
+tasks.withType(Test).configureEach {
+    systemProperty 'projectVersion', projectVersion
+    systemProperty 'currentJdk', JavaVersion.current().majorVersion
+}
+
 apply {
     from rootProject.layout.projectDirectory.file('gradle/docs-config.gradle')
+    from rootProject.layout.projectDirectory.file('gradle/test-config.gradle')
 }

grails-gradle/plugins/src/main/groovy/org/grails/gradle/plugin/core/GrailsGradlePlugin.groovy

@@ -54,6 +54,7 @@ import org.gradle.api.tasks.TaskContainer
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.api.tasks.compile.GroovyCompile
 import org.gradle.api.tasks.testing.Test
+import org.gradle.jvm.toolchain.JavaToolchainService
 import org.gradle.language.jvm.tasks.ProcessResources
 import org.gradle.process.JavaForkOptions
 import org.gradle.tooling.provider.model.ToolingModelBuilderRegistry
@@ -556,6 +557,44 @@ class GrailsGradlePlugin extends GroovyPlugin {
         String grailsEnvSystemProperty = System.getProperty(Environment.KEY)
         tasks.withType(Test).configureEach(systemPropertyConfigurer.curry(grailsEnvSystemProperty ?: Environment.TEST.getName()))
         tasks.withType(JavaExec).configureEach(systemPropertyConfigurer.curry(grailsEnvSystemProperty ?: Environment.DEVELOPMENT.getName()))
+
+        configureToolchainForForkTasks(project)
+    }
+
+    /**
+     * Configures {@link JavaExec} tasks to inherit the project's Java toolchain.
+     *
+     * <p>Gradle's {@code JavaPlugin} already sets toolchain conventions on
+     * {@code JavaCompile}, {@code Javadoc}, and {@code Test} tasks, but does
+     * <strong>not</strong> set them on {@code JavaExec} tasks. This means forked
+     * JVM processes (dbm-* migration tasks, console, shell, and application
+     * context commands) use the JDK running Gradle instead of the project's
+     * configured toolchain. When the project targets a different JDK version
+     * than the one running Gradle, this causes {@code UnsupportedClassVersionError}
+     * or silent runtime failures.</p>
+     *
+     * <p>This method only acts when the user has explicitly configured a toolchain
+     * via {@code java.toolchain.languageVersion}. When no toolchain is configured,
+     * behavior is unchanged - tasks use the JDK running Gradle as before.</p>
+     *
+     * <p>Uses {@code convention()} so that individual tasks can still override
+     * the launcher via {@code javaLauncher.set(...)} if needed.</p>
+     *
+     * @param project the Gradle project
+     * @since 7.0.8
+     */
+    protected void configureToolchainForForkTasks(Project project) {
+        project.afterEvaluate {
+            def javaExtension = project.extensions.findByType(org.gradle.api.plugins.JavaPluginExtension)
+            if (javaExtension?.toolchain?.languageVersion?.isPresent()) {
+                def toolchainService = project.extensions.getByType(JavaToolchainService)
+                def launcher = toolchainService.launcherFor(javaExtension.toolchain)
+
+                project.tasks.withType(JavaExec).configureEach { JavaExec task ->
+                    task.javaLauncher.convention(launcher)
+                }
+            }
+        }
     }
 
     protected void configureConsoleTask(Project project) {

grails-gradle/plugins/src/test/groovy/org/grails/gradle/plugin/core/GradleSpecification.groovy

@@ -0,0 +1,134 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+package org.grails.gradle.plugin.core
+
+import org.gradle.testkit.runner.BuildResult
+import org.gradle.testkit.runner.GradleRunner
+import org.gradle.testkit.runner.TaskOutcome
+import spock.lang.Specification
+
+import java.nio.file.FileVisitResult
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.SimpleFileVisitor
+import java.nio.file.attribute.BasicFileAttributes
+
+/**
+ * Base class for Gradle plugin functional tests using TestKit.
+ *
+ * <p>Adapted from the {@code GradleSpecification} in the
+ * {@code apache/grails-gradle-publish} project. Handles temp directory
+ * management, GradleRunner setup, test resource project copying, and
+ * common build assertions.</p>
+ *
+ * @since 7.0.8
+ */
+abstract class GradleSpecification extends Specification {
+
+    private static Path basePath
+    private static GradleRunner gradleRunner
+
+    /** Project version injected by Gradle test config. */
+    protected static final String PROJECT_VERSION = System.getProperty('projectVersion')
+
+    /** Current JDK major version injected by Gradle test config. */
+    protected static final int CURRENT_JDK = Integer.parseInt(System.getProperty('currentJdk'))
+
+    void setupSpec() {
+        basePath = Files.createTempDirectory('gradle-projects')
+        Path testKitDir = Files.createDirectories(basePath.resolve('.gradle'))
+        gradleRunner = GradleRunner.create()
+                .withPluginClasspath()
+                .withTestKitDir(testKitDir.toFile())
+    }
+
+    void cleanup() {
+        basePath?.toFile()?.listFiles()?.each {
+            if (it.name == '.gradle') {
+                return
+            }
+            it.deleteDir()
+        }
+    }
+
+    void cleanupSpec() {
+        basePath?.toFile()?.deleteDir()
+    }
+
+    /**
+     * Sets up a test project from resource files under
+     * {@code src/test/resources/test-projects/{projectName}}.
+     *
+     * <p>Files are copied to a temp directory. Any occurrence of
+     * {@code __CURRENT_JDK__} in {@code .gradle} files is replaced
+     * with the actual current JDK version, and {@code __PROJECT_VERSION__}
+     * is replaced with the actual project version.</p>
+     */
+    protected GradleRunner setupTestResourceProject(String projectName) {
+        Path destination = basePath.resolve(projectName)
+        Files.createDirectories(destination)
+
+        Path source = Path.of("src/test/resources/test-projects/${projectName}")
+        copyDirectory(source, destination)
+
+        gradleRunner.withProjectDir(destination.toFile())
+    }
+
+    /**
+     * Executes a Gradle task and returns the build result.
+     */
+    protected BuildResult executeTask(String taskName, List<String> otherArgs = []) {
+        List<String> args = [taskName, '--stacktrace']
+        args.addAll(otherArgs)
+        gradleRunner.withArguments(args).forwardOutput().build()
+    }
+
+    /**
+     * Asserts that the given task succeeded.
+     */
+    protected void assertTaskSuccess(String taskName, BuildResult result) {
+        def task = result.tasks.find { it.path.endsWith(":${taskName}") }
+        assert task != null : "Task '${taskName}' not found in build result"
+        assert task.outcome == TaskOutcome.SUCCESS : "Task '${taskName}' outcome was ${task.outcome}"
+    }
+
+    private void copyDirectory(Path source, Path destination) {
+        Files.walkFileTree(source, new SimpleFileVisitor<Path>() {
+            @Override
+            FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
+                Files.createDirectories(destination.resolve(source.relativize(dir)))
+                FileVisitResult.CONTINUE
+            }
+
+            @Override
+            FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+                Path target = destination.resolve(source.relativize(file))
+                if (file.toString().endsWith('.gradle') || file.toString().endsWith('.properties')) {
+                    String content = Files.readString(file)
+                            .replace('__CURRENT_JDK__', String.valueOf(CURRENT_JDK))
+                            .replace('__PROJECT_VERSION__', PROJECT_VERSION)
+                    Files.writeString(target, content)
+                } else {
+                    Files.copy(file, target)
+                }
+                FileVisitResult.CONTINUE
+            }
+        })
+    }
+}

grails-gradle/plugins/src/test/groovy/org/grails/gradle/plugin/core/GrailsGradlePluginToolchainSpec.groovy

@@ -0,0 +1,136 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+package org.grails.gradle.plugin.core
+
+/**
+ * Tests that {@link GrailsGradlePlugin} propagates the project's Java toolchain
+ * to JavaExec tasks via {@code javaLauncher.convention()}.
+ *
+ * <p>Without the fix, JavaExec tasks spawned by Grails (dbm-* migration
+ * commands, console, shell, application context commands) use the JDK
+ * running Gradle instead of the project's configured toolchain.</p>
+ *
+ * @since 7.0.8
+ * @see GrailsGradlePlugin#configureToolchainForForkTasks
+ */
+class GrailsGradlePluginToolchainSpec extends GradleSpecification {
+
+    // ----------------------------------------------------------------
+    // Toolchain propagation
+    // ----------------------------------------------------------------
+
+    def "JavaExec tasks inherit project toolchain"() {
+        given:
+        setupTestResourceProject('toolchain-javaexec')
+
+        when:
+        def result = executeTask('checkToolchain')
+
+        then:
+        result.output.contains("TOOLCHAIN_VERSION=${CURRENT_JDK}")
+    }
+
+    def "Test tasks inherit project toolchain"() {
+        given:
+        setupTestResourceProject('toolchain-test')
+
+        when:
+        def result = executeTask('checkTestToolchain')
+
+        then:
+        result.output.contains("TEST_TOOLCHAIN_VERSION=${CURRENT_JDK}")
+    }
+
+    def "ApplicationContextCommandTask inherits toolchain via grails-web plugin"() {
+        given:
+        setupTestResourceProject('toolchain-command')
+
+        when:
+        def result = executeTask('checkCommandToolchain')
+
+        then:
+        result.output.contains("CMD_TOOLCHAIN_VERSION=${CURRENT_JDK}")
+    }
+
+    def "convention allows individual task override via set()"() {
+        given:
+        setupTestResourceProject('toolchain-override')
+
+        when:
+        def result = executeTask('checkOverride')
+
+        then:
+        result.output.contains("OVERRIDE_VERSION=${CURRENT_JDK}")
+    }
+
+    // ----------------------------------------------------------------
+    // Backwards compatibility (no toolchain configured)
+    // ----------------------------------------------------------------
+
+    def "JavaExec tasks work without errors when no toolchain configured"() {
+        given:
+        setupTestResourceProject('no-toolchain-javaexec')
+
+        when:
+        def result = executeTask('checkToolchain')
+
+        then:
+        result.output.contains('HAS_LAUNCHER=')
+    }
+
+    def "GrailsWebGradlePlugin works without errors when no toolchain configured"() {
+        given:
+        setupTestResourceProject('no-toolchain-web')
+
+        when:
+        def result = executeTask('checkNoError')
+
+        then:
+        result.output.contains('WEB_PLUGIN_OK=true')
+    }
+
+    // ----------------------------------------------------------------
+    // Fork settings preservation
+    // ----------------------------------------------------------------
+
+    def "configureForkSettings applies system properties and default heap sizes"() {
+        given:
+        setupTestResourceProject('fork-settings-defaults')
+
+        when:
+        def result = executeTask('inspectSysProps')
+
+        then:
+        result.output.contains('HAS_ENV=true')
+        result.output.contains('MIN_HEAP=768m')
+        result.output.contains('MAX_HEAP=768m')
+    }
+
+    def "custom heap sizes are not overridden by fork settings"() {
+        given:
+        setupTestResourceProject('fork-settings-custom')
+
+        when:
+        def result = executeTask('inspectHeap')
+
+        then:
+        result.output.contains('MIN_HEAP=512m')
+        result.output.contains('MAX_HEAP=2g')
+    }
+}

grails-gradle/plugins/src/test/resources/test-projects/fork-settings-custom/build.gradle

@@ -0,0 +1,18 @@
+plugins {
+    id 'org.apache.grails.gradle.grails-app'
+}
+
+tasks.register('customHeap', JavaExec) {
+    classpath = files()
+    mainClass = 'does.not.Matter'
+    minHeapSize = '512m'
+    maxHeapSize = '2g'
+}
+
+tasks.register('inspectHeap') {
+    doLast {
+        def task = tasks.named('customHeap', JavaExec).get()
+        println "MIN_HEAP=${task.minHeapSize}"
+        println "MAX_HEAP=${task.maxHeapSize}"
+    }
+}

grails-gradle/plugins/src/test/resources/test-projects/fork-settings-custom/gradle.properties

@@ -0,0 +1 @@
+grailsVersion=__PROJECT_VERSION__

grails-gradle/plugins/src/test/resources/test-projects/fork-settings-custom/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'test-toolchain'

grails-gradle/plugins/src/test/resources/test-projects/fork-settings-defaults/build.gradle

@@ -0,0 +1,18 @@
+plugins {
+    id 'org.apache.grails.gradle.grails-app'
+}
+
+tasks.register('checkSysProps', JavaExec) {
+    classpath = files()
+    mainClass = 'does.not.Matter'
+}
+
+tasks.register('inspectSysProps') {
+    doLast {
+        def task = tasks.named('checkSysProps', JavaExec).get()
+        def sysProps = task.systemProperties
+        println "HAS_ENV=${sysProps.containsKey('grails.env')}"
+        println "MIN_HEAP=${task.minHeapSize}"
+        println "MAX_HEAP=${task.maxHeapSize}"
+    }
+}

grails-gradle/plugins/src/test/resources/test-projects/fork-settings-defaults/gradle.properties

@@ -0,0 +1 @@
+grailsVersion=__PROJECT_VERSION__