Extract ELVDS sealed-hierarchy change test into standalone preview jtreg test

Author: biboudis

test/langtools/tools/javac/patterns/EnhancedVariableDeclSealedTypeChanges.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+/*
+ * @test
+ * @summary Verify enhanced variable declarations when sealed hierarchy changes after compilation.
+ * @enablePreview
+ * @compile EnhancedVariableDeclSealedTypeChanges.java
+ * @compile EnhancedVariableDeclSealedTypeChanges2.java
+ * @run main EnhancedVariableDeclSealedTypeChanges
+ */
+
+import java.util.function.Consumer;
+
+public class EnhancedVariableDeclSealedTypeChanges {
+    public static void main(String... args) throws Exception {
+        new EnhancedVariableDeclSealedTypeChanges().run();
+    }
+
+    void run() throws Exception {
+        doRun(this::enhancedVariableDeclStatement);
+        doRun(this::enhancedVariableDeclStatementNoComponentAccess);
+    }
+
+    <T> void doRun(Consumer<T> consumer) throws Exception {
+        consumer.accept((T) new A(1, 2));
+
+        try {
+            consumer.accept((T) Class.forName("EnhancedVariableDeclSealedTypeChangesClass")
+                                     .getDeclaredConstructor()
+                                     .newInstance());
+            throw new AssertionError("Expected an exception, but none thrown.");
+        } catch (Throwable ex) {
+            validateMatchException(ex);
+        }
+    }
+
+    void validateMatchException(Throwable t) {
+        if (!(t instanceof MatchException)) {
+            throw new AssertionError("Unexpected exception kind", t);
+        }
+    }
+
+    void enhancedVariableDeclStatement(EnhancedVariableDeclSealedTypeChangesIntf obj) {
+        A(Integer x, Integer y) = obj;
+        if (x + y < 0) {
+            throw new AssertionError("unreachable");
+        }
+    }
+
+    void enhancedVariableDeclStatementNoComponentAccess(EnhancedVariableDeclSealedTypeChangesIntf obj) {
+        A(var x, var y) = obj;
+        if (obj == null) {
+            throw new AssertionError("unreachable");
+        }
+    }
+
+    record A(Integer x, Integer y) implements EnhancedVariableDeclSealedTypeChangesIntf {}
+}
+
+sealed interface EnhancedVariableDeclSealedTypeChangesIntf
+        permits EnhancedVariableDeclSealedTypeChanges.A {}

test/langtools/tools/javac/patterns/EnhancedVariableDeclSealedTypeChanges2.java

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+sealed interface EnhancedVariableDeclSealedTypeChangesIntf
+        permits EnhancedVariableDeclSealedTypeChanges.A, EnhancedVariableDeclSealedTypeChangesClass {}
+
+final class EnhancedVariableDeclSealedTypeChangesClass
+        implements EnhancedVariableDeclSealedTypeChangesIntf {}