Use reflective access for JavaModuleDetector methods (#173)

Author: jjohannes

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Java Module Testing Gradle Plugin - Changelog
 
+## Version 1.8.1
+* [#172](https://github.com/gradlex-org/java-module-testing/issues/172) Fix incompatibility with Gradle 9.5.0+
+
 ## Version 1.8
 * [#143](https://github.com/gradlex-org/java-module-testing/issues/143) Fully support other source sets than 'main' in whitebox tests
 * [#114](https://github.com/gradlex-org/java-module-testing/issues/114) Fix: issue where the plugin causes a 'mutating a configuration after it has been resolved' error

build.gradle.kts

@@ -15,4 +15,5 @@ publishingConventions {
     }
 }
 
-testingConventions { testGradleVersions("7.4", "7.6.5", "8.0.2", "8.14.2") }
+// 9.4.1 is the last version where 'JavaModuleDetector' is a class and not an interface
+testingConventions { testGradleVersions("7.4", "7.6.5", "8.0.2", "8.14.2", "9.4.1") }

src/main/java/org/gradlex/javamodule/testing/internal/actions/JavaCompileSetModulePathAction.java

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 package org.gradlex.javamodule.testing.internal.actions;
 
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 import javax.inject.Inject;
@@ -31,10 +32,22 @@ public void execute(Task task) {
 
         // Since for Gradle this sources set does not look like a module, we have to define the module path ourselves
         compilerArgs.add("--module-path");
-        compilerArgs.add(getJavaModuleDetector()
-                .inferModulePath(true, classpathAndModulePath)
-                .getAsPath());
-        javaCompile.setClasspath(getJavaModuleDetector().inferClasspath(true, classpathAndModulePath));
+        compilerArgs.add(infer("ModulePath", classpathAndModulePath).getAsPath());
+        javaCompile.setClasspath(infer("Classpath", classpathAndModulePath));
         javaCompile.getOptions().setCompilerArgs(compilerArgs);
     }
+
+    /**
+     * Use reflective access for JavaModuleDetector methods so that it does not matter if JavaModuleDetector is a
+     * class (<9.5.0) or an interface (9.5.0+).
+     */
+    private FileCollection infer(String pathType, FileCollection classpathAndModulePath) {
+        try {
+            Method inferModulePath =
+                    JavaModuleDetector.class.getDeclaredMethod("infer" + pathType, boolean.class, FileCollection.class);
+            return (FileCollection) inferModulePath.invoke(getJavaModuleDetector(), true, classpathAndModulePath);
+        } catch (ReflectiveOperationException e) {
+            throw new RuntimeException(e);
+        }
+    }
 }