Support JEP-441: Pattern Matching for switch for Java 21+

rewrite-groovy/src/main/java/org/openrewrite/groovy/GroovyParserVisitor.java

@@ -650,7 +650,7 @@ public List<J.Annotation> visitAndGetAnnotations(AnnotatedNode node) {
             for (AnnotationNode annotationNode : node.getAnnotations()) {
                 // The groovy compiler can add or remove annotations for AST transformations.
                 // Because @groovy.transform.Immutable is discarded in favour of other transform annotations, the removed annotation must be parsed by hand.
-                if (sourceStartsWith("@" + Immutable.class.getSimpleName()) || sourceStartsWith("@" + Immutable.class.getCanonicalName()) ) {
+                if (sourceStartsWith("@" + Immutable.class.getSimpleName()) || sourceStartsWith("@" + Immutable.class.getCanonicalName())) {
                     visitAnnotation(new AnnotationNode(new ClassNode(Immutable.class)));
                     paramAnnotations.add(pollQueue());
                 }
@@ -1135,10 +1135,12 @@ public void visitCaseStatement(CaseStatement statement) {
                     J.Case.Type.Statement,
                     null,
                     JContainer.build(singletonList(JRightPadded.build(visit(statement.getExpression())))),
+                    null,
+                    null,
                     statement.getCode() instanceof EmptyStatement ?
                             JContainer.build(sourceBefore(":"), convertStatements(emptyList()), Markers.EMPTY) :
-                            JContainer.build(sourceBefore(":"), convertStatements(((BlockStatement) statement.getCode()).getStatements()), Markers.EMPTY)
-                    , null)
+                            JContainer.build(sourceBefore(":"), convertStatements(((BlockStatement) statement.getCode()).getStatements()), Markers.EMPTY),
+                    null)
             );
         }
 
@@ -1149,6 +1151,8 @@ private J.Case visitDefaultCaseStatement(BlockStatement statement) {
                     J.Case.Type.Statement,
                     null,
                     JContainer.build(singletonList(JRightPadded.build(new J.Identifier(randomId(), EMPTY, Markers.EMPTY, emptyList(), skip("default"), null, null)))),
+                    null,
+                    null,
                     JContainer.build(sourceBefore(":"), convertStatements(statement.getStatements()), Markers.EMPTY),
                     null
             );
@@ -1609,7 +1613,7 @@ public void visitGStringExpression(GStringExpression gstring) {
                 }
             }
 
-            queue.add(new G.GString(randomId(), fmt, Markers.EMPTY, delimiter, strings,typeMapping.type(gstring.getType())));
+            queue.add(new G.GString(randomId(), fmt, Markers.EMPTY, delimiter, strings, typeMapping.type(gstring.getType())));
             skip(delimiter); // Closing delim for GString
         }
 
@@ -2778,6 +2782,7 @@ private static ClassNode staticType(Parameter parameter) {
     }
 
     private static final Map<String, J.Modifier.Type> modifierNameToType;
+
     static {
         modifierNameToType = new LinkedHashMap<>();
         modifierNameToType.put("def", J.Modifier.Type.LanguageExtension);

rewrite-java-11/src/main/java/org/openrewrite/java/isolated/ReloadableJava11ParserVisitor.java

@@ -346,6 +346,8 @@ public J visitCase(CaseTree node, Space fmt) {
                         ),
                         Markers.EMPTY
                 ),
+                null,
+                null,
                 JContainer.build(sourceBefore(":"), convertStatements(node.getStatements()), Markers.EMPTY),
                 null
         );

rewrite-java-17/src/main/java/org/openrewrite/java/isolated/ReloadableJava17ParserVisitor.java

@@ -355,6 +355,8 @@ public J visitCase(CaseTree node, Space fmt) {
                                 convertAll(node.getExpressions(), commaDelim, t -> EMPTY),
                         Markers.EMPTY
                 ),
+                null,
+                null,
                 JContainer.build(
                         sourceBefore(type == J.Case.Type.Rule ? "->" : ":"),
                         convertStatements(node.getStatements()),

rewrite-java-21/src/main/java/org/openrewrite/java/isolated/ReloadableJava21ParserVisitor.java

@@ -348,13 +348,15 @@ public J visitCase(CaseTree node, Space fmt) {
                 Markers.EMPTY,
                 type,
                 null,
+                null,
                 JContainer.build(
-                        node.getExpressions().isEmpty() ? EMPTY : sourceBefore("case"),
-                        node.getExpressions().isEmpty() ?
+                        node.getLabels().isEmpty() ? EMPTY : sourceBefore("case"),
+                        node.getLabels().isEmpty() || node.getLabels().getFirst() instanceof DefaultCaseLabelTree ?
                                 List.of(JRightPadded.build(new J.Identifier(randomId(), Space.EMPTY, Markers.EMPTY, emptyList(), skip("default"), null, null))) :
-                                convertAll(node.getExpressions(), commaDelim, t -> EMPTY),
+                                convertAll(node.getLabels(), commaDelim, ignored -> node.getGuard() != null ? sourceBefore("when", '-') : EMPTY),
                         Markers.EMPTY
                 ),
+                convert(node.getGuard()),
                 JContainer.build(
                         sourceBefore(type == J.Case.Type.Rule ? "->" : ":"),
                         convertStatements(node.getStatements()),
@@ -779,12 +781,26 @@ public J visitInstanceOf(InstanceOfTree node, Space fmt) {
         return new J.InstanceOf(randomId(), fmt, Markers.EMPTY,
                 convert(node.getExpression(), t -> sourceBefore("instanceof")),
                 convert(node.getType()),
-                node.getPattern() instanceof JCBindingPattern b ?
-                        new J.Identifier(randomId(), sourceBefore(b.getVariable().getName().toString()), Markers.EMPTY, emptyList(), b.getVariable().getName().toString(),
-                                type, typeMapping.variableType(b.var.sym)) : null,
+                getNodePattern(node.getPattern(), type),
                 type);
     }
 
+    private @Nullable J getNodePattern(@Nullable PatternTree pattern, JavaType type) {
+        if (pattern instanceof JCBindingPattern b) {
+            return new J.Identifier(randomId(), sourceBefore(b.getVariable().getName().toString()), Markers.EMPTY, emptyList(), b.getVariable().getName().toString(),
+                    type, typeMapping.variableType(b.var.sym));
+        } else {
+            if (pattern == null) {
+                return null;
+            }
+            int saveCursor = cursor;
+            int endCursor = max(endPos(pattern), cursor);
+            cursor = endCursor;
+            return new J.Unknown(randomId(), whitespace(), Markers.EMPTY, new J.Unknown.Source(randomId(), whitespace(), Markers.EMPTY, source.substring(saveCursor, endCursor)));
+
+        }
+    }
+
     @Override
     public J visitIntersectionType(IntersectionTypeTree node, Space fmt) {
         JContainer<TypeTree> bounds = node.getBounds().isEmpty() ? null :

rewrite-java-8/src/main/java/org/openrewrite/java/ReloadableJava8ParserVisitor.java

@@ -343,6 +343,8 @@ public J visitCase(CaseTree node, Space fmt) {
                         ),
                         Markers.EMPTY
                 ),
+                null,
+                null,
                 JContainer.build(sourceBefore(":"), convertStatements(node.getStatements()), Markers.EMPTY),
                 null
         );
@@ -1787,17 +1789,17 @@ private <J2 extends J> List<JRightPadded<J2>> convertAll(List<? extends Tree> tr
 
     private Space statementDelim(@Nullable Tree t) {
         if (t instanceof JCAssert ||
-                t instanceof JCAssign ||
-                t instanceof JCAssignOp ||
-                t instanceof JCBreak ||
-                t instanceof JCContinue ||
-                t instanceof JCDoWhileLoop ||
-                t instanceof JCImport ||
-                t instanceof JCMethodInvocation ||
-                t instanceof JCNewClass ||
-                t instanceof JCReturn ||
-                t instanceof JCThrow ||
-                t instanceof JCUnary) {
+            t instanceof JCAssign ||
+            t instanceof JCAssignOp ||
+            t instanceof JCBreak ||
+            t instanceof JCContinue ||
+            t instanceof JCDoWhileLoop ||
+            t instanceof JCImport ||
+            t instanceof JCMethodInvocation ||
+            t instanceof JCNewClass ||
+            t instanceof JCReturn ||
+            t instanceof JCThrow ||
+            t instanceof JCUnary) {
             return sourceBefore(";");
         }
 
@@ -1808,7 +1810,7 @@ private Space statementDelim(@Nullable Tree t) {
         if (t instanceof JCExpressionStatement) {
             ExpressionTree expTree = ((ExpressionStatementTree) t).getExpression();
             if (expTree instanceof ErroneousTree) {
-                return Space.build(source.substring(((JCTree) expTree).getEndPosition(endPosTable),((JCTree) t).getEndPosition(endPosTable)), Collections.emptyList());
+                return Space.build(source.substring(((JCTree) expTree).getEndPosition(endPosTable), ((JCTree) t).getEndPosition(endPosTable)), Collections.emptyList());
             } else {
                 return sourceBefore(";");
             }
@@ -1972,7 +1974,7 @@ private int positionOfNext(String untilDelim, @Nullable Character stop) {
                     char c2 = source.charAt(delimIndex + 1);
                     switch (c1) {
                         case '/':
-                            switch(c2) {
+                            switch (c2) {
                                 case '/':
                                     inSingleLineComment = true;
                                     delimIndex++;
@@ -1984,7 +1986,7 @@ private int positionOfNext(String untilDelim, @Nullable Character stop) {
                             }
                             break;
                         case '*':
-                            if(c2 == '/') {
+                            if (c2 == '/') {
                                 inMultiLineComment = false;
                                 delimIndex++;
                                 continue;
@@ -2051,7 +2053,7 @@ private List<String> listFlags(long flags) {
                     try {
                         // FIXME instanceof probably not right here...
                         return field.get(null) instanceof Long &&
-                                field.getName().matches("[A-Z_]+");
+                               field.getName().matches("[A-Z_]+");
                     } catch (IllegalAccessException e) {
                         throw new RuntimeException(e);
                     }

rewrite-java-tck/src/main/java/org/openrewrite/java/tree/RecordPatternMatchingTest.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed 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
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.openrewrite.java.tree;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.java.MinimumJava21;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+import org.openrewrite.test.TypeValidation;
+
+import static org.openrewrite.java.Assertions.java;
+
+@MinimumJava21
+class RecordPatternMatchingTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.typeValidationOptions(TypeValidation.all().unknown(false));
+    }
+
+    @Test
+    void shouldParseJava21PatternMatchForRecords() {
+        rewriteRun(
+          java(
+            //language=java
+            """
+              record Point(int x, int y) {}
+              class Test {
+                  void printSum(Object obj) {
+                      if (obj instanceof Point(int x, int y)) {
+                          System.out.println(x+y);
+                      }
+                  }
+              }
+              """
+          ));
+    }
+
+    @Test
+    void shouldParseJava21NestedPatternMatchForRecords() {
+        rewriteRun(
+          java(
+            //language=java
+            """
+              record Point(int x, int y) {}
+              enum Color { RED, GREEN, BLUE }
+              record ColoredPoint(Point p, Color c) {}
+              record Rectangle(ColoredPoint upperLeft, ColoredPoint lowerRight) {}
+              class Test {
+                  void printColorOfUpperLeftPoint(Rectangle r) {
+                      if (r instanceof Rectangle(ColoredPoint(Point p, Color c),
+                                                 ColoredPoint lr)) {
+                          System.out.println(c);
+                      }
+                  }
+              }
+              """
+          ));
+    }
+
+}