Skip preview feature tests against future JRE versions (eclipse-jdt#4329)

Most preview related tests fail when the JRE version is higher than the
highest compliance level supported by ECJ. Guard such tests from being
run in such cases.

eclipse-jdt#4329

Author: jarthana

org.eclipse.jdt.compiler.apt.tests/src/org/eclipse/jdt/compiler/apt/tests/RecordElementsTests.java

@@ -189,8 +189,6 @@ protected void internalTestWithPreview(JavaCompiler compiler, String processor,
 			options.add("-source");
 			options.add(compliance);
 		}
-//		if (preview)
-//			options.add("--enable-preview");
 		BatchTestUtils.compileInModuleMode(compiler, options, processor, targetFolder, null, true, processBinaries);
 		// If it succeeded, the processor will have set this property to "succeeded";
 		// if not, it will set it to an error value.

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/ImplicitlyDeclaredClassesTest.java

@@ -15,7 +15,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.stream.Stream;
-import javax.lang.model.SourceVersion;
+import org.eclipse.jdt.core.tests.util.PreviewTest;
 import org.eclipse.jdt.core.util.ClassFileBytesDisassembler;
 import org.eclipse.jdt.core.util.ClassFormatException;
 import org.eclipse.jdt.internal.compiler.CompilationResult;
@@ -32,6 +32,7 @@
 import org.eclipse.jdt.internal.compiler.problem.ProblemReporter;
 import org.junit.Test;
 
+@PreviewTest
 public class ImplicitlyDeclaredClassesTest extends AbstractRegressionTest9 {
 	public static boolean optimizeStringLiterals = false;
 	private static final JavacTestOptions JAVAC_OPTIONS = new JavacTestOptions("--enable-preview -source 24");
@@ -49,7 +50,6 @@ public ImplicitlyDeclaredClassesTest(String testName){
 	protected void setUp() throws Exception {
 		this.runJavacOptIn = true;
 		super.setUp();
-		this.isJRE25Plus = isRunningIn25Jre();
  	}
 	@Override
 	protected void tearDown() throws Exception {
@@ -69,15 +69,6 @@ public static junit.framework.Test suite() {
 	protected Map<String, String> getCompilerOptions() {
 		return getCompilerOptions(true);
 	}
-	private boolean isJRE25Plus = false;
-	public boolean isRunningIn25Jre() {
-		try {
-			SourceVersion.valueOf("RELEASE_25");
-		} catch(IllegalArgumentException iae) {
-			return false;
-		}
-		return true;
-	}
 	// Enables the tests to run individually
 	protected Map<String, String> getCompilerOptions(boolean previewFlag) {
 		Map<String, String> defaultOptions = super.getCompilerOptions();
@@ -90,14 +81,10 @@ protected Map<String, String> getCompilerOptions(boolean previewFlag) {
 	}
 	@Override
 	protected void runConformTest(String[] testFiles, String expectedOutput) {
-		if(this.isJRE25Plus)
-			return;
 		runConformTest(testFiles, expectedOutput, null, VMARGS, new JavacTestOptions("-source 24 --enable-preview"));
 	}
 	@Override
 	protected void runConformTest(String[] testFiles, String expectedOutput, Map<String, String> customOptions) {
-		if(this.isJRE25Plus)
-			return;
 		runConformTest(testFiles, expectedOutput, customOptions, VMARGS, JAVAC_OPTIONS);
 	}
 	@Override
@@ -274,8 +261,6 @@ class XYZ {
 	// Test implicit type with a valid candidate main method (public but no static, and String[] argument)
 	@Test
 	public void testImplicitType006() throws IOException, ClassFormatException {
-		if (this.isJRE25Plus)
-			return;
 		try {
 			runConformTest(
 					new String[] {"X.java",
@@ -383,8 +368,6 @@ public static void main(String[] args) {
 		"Hello2");
 	}
 	public void testGH3137b() {
-		if (this.isJRE25Plus)
-			return;
 		runConformTest(new String[] {
 				"X.java",
 				"""
@@ -400,8 +383,6 @@ public static void main(String[] args) {
 		JavacTestOptions.SKIP);
 	}
 	public void testGH3714() {
-		if (this.isJRE25Plus)
-			return;
 		runConformTest(new String[] {
 				"Main.java",
 				"""

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/PreviewFlagTest.java

@@ -15,12 +15,14 @@
 import java.io.IOException;
 import java.util.Map;
 import junit.framework.Test;
+import org.eclipse.jdt.core.tests.util.PreviewTest;
 import org.eclipse.jdt.core.util.ClassFileBytesDisassembler;
 import org.eclipse.jdt.core.util.ClassFormatException;
 import org.eclipse.jdt.internal.compiler.batch.FileSystem;
 import org.eclipse.jdt.internal.compiler.env.INameEnvironment;
 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
 
+@PreviewTest
 public class PreviewFlagTest extends AbstractRegressionTest9 {
 
 	private static final JavacTestOptions JAVAC_OPTIONS = new JavacTestOptions("--enable-preview -source 24");

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/PrimitiveInPatternsTest.java

@@ -14,10 +14,12 @@
 
 import java.util.Map;
 import junit.framework.Test;
+import org.eclipse.jdt.core.tests.util.PreviewTest;
 import org.eclipse.jdt.internal.compiler.batch.FileSystem;
 import org.eclipse.jdt.internal.compiler.env.INameEnvironment;
 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
 
+@PreviewTest
 public class PrimitiveInPatternsTest extends AbstractRegressionTest9 {
 
 	private static final JavacTestOptions JAVAC_OPTIONS = new JavacTestOptions("--enable-preview -source 24");

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SuperAfterStatementsTest.java

@@ -15,12 +15,13 @@
 import java.io.IOException;
 import java.util.Map;
 import junit.framework.Test;
+import org.eclipse.jdt.core.tests.util.PreviewTest;
 import org.eclipse.jdt.core.util.ClassFileBytesDisassembler;
 import org.eclipse.jdt.core.util.ClassFormatException;
 import org.eclipse.jdt.internal.compiler.batch.FileSystem;
 import org.eclipse.jdt.internal.compiler.env.INameEnvironment;
 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
-
+@PreviewTest
 public class SuperAfterStatementsTest extends AbstractRegressionTest9 {
 
 	private static final JavacTestOptions JAVAC_OPTIONS = new JavacTestOptions("--enable-preview -source 24");

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/util/AbstractCompilerTest.java

@@ -14,6 +14,7 @@
 package org.eclipse.jdt.core.tests.util;
 
 import java.io.File;
+import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
@@ -194,10 +195,18 @@ private static Test buildComplianceTestSuite(List testClasses, Class setupClass,
 		}
 		if (complianceSuite == null)
 			return null;
-
+		String specVersion = System.getProperty("java.specification.version");
+		int spec = Integer.parseInt(specVersion);
+		boolean futureJREUsed = spec > Integer.parseInt(CompilerOptions.getLatestVersion());
 		// add tests
 		for (int i=0, m=testClasses.size(); i<m ; i++) {
 			Class testClass = (Class)testClasses.get(i);
+			if (futureJREUsed) {
+				Annotation annotation = testClass.getAnnotation(PreviewTest.class);
+				if (annotation != null) {
+					continue;
+				}
+			}
 			TestSuite suite = new TestSuite(testClass.getName());
 			int inheritedDepth = 0;
 			try {

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/util/PreviewTest.java

@@ -0,0 +1,19 @@
+package org.eclipse.jdt.core.tests.util;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that the target test suite tests preview Java features. In certain cases
+ * a test is not meant to be run with a future JRE. For e.g., if the highest supported
+ * version by ECJ is 24, running certain tests, especially those related to preview
+ * features, may produce unexpected results when run with a JRE 25. Authors of test
+ * can mark such tests with this annotation and allow them to be skipped under
+ * conditions such as above.
+ *
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface PreviewTest {}