Fix Java 21 parser dropping var in record pattern binding variables (#6781)

* Fix Java 21 parser dropping `var` in record pattern binding variables

* Replicate the same fix to the Java 25 parser

---------

Co-authored-by: Oliver Wolff <23139298+cuioss@users.noreply.github.com>
Co-authored-by: Tim te Beek <tim@moderne.io>

Author: cuioss-oliver

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

@@ -1743,8 +1743,9 @@ private J.VariableDeclarations visitVariables(List<VariableTree> nodes, Space fm
             typeExpr = convert(vartype);
         }
 
-        if (typeExpr == null && node.declaredUsingVar()) {
-            typeExpr = new J.Identifier(randomId(), sourceBefore("var"), Markers.build(singletonList(JavaVarKeyword.build())), emptyList(), "var", typeMapping.type(vartype), null);
+        if (typeExpr == null && (node.declaredUsingVar() ||
+                ((node.sym.flags() & Flags.MATCH_BINDING) != 0 && source.startsWith("var", indexOfNextNonWhitespace(cursor, source))))) {
+            typeExpr = new J.Identifier(randomId(), sourceBefore("var"), Markers.build(singletonList(JavaVarKeyword.build())), emptyList(), "var", vartype != null ? typeMapping.type(vartype) : typeMapping.type(node.sym.type), null);
         }
 
         if (typeExpr != null && !typeExprAnnotations.isEmpty()) {

rewrite-java-25/src/main/java/org/openrewrite/java/isolated/ReloadableJava25ParserVisitor.java

@@ -1775,8 +1775,9 @@ private J.VariableDeclarations visitVariables(List<VariableTree> nodes, Space fm
             typeExpr = convert(vartype);
         }
 
-        if (typeExpr == null && node.declaredUsingVar()) {
-            typeExpr = new J.Identifier(randomId(), sourceBefore("var"), Markers.build(singletonList(JavaVarKeyword.build())), emptyList(), "var", typeMapping.type(vartype), null);
+        if (typeExpr == null && (node.declaredUsingVar() ||
+                ((node.sym.flags() & Flags.MATCH_BINDING) != 0 && source.startsWith("var", indexOfNextNonWhitespace(cursor, source))))) {
+            typeExpr = new J.Identifier(randomId(), sourceBefore("var"), Markers.build(singletonList(JavaVarKeyword.build())), emptyList(), "var", vartype != null ? typeMapping.type(vartype) : typeMapping.type(node.sym.type), null);
         }
 
         if (typeExpr != null && !typeExprAnnotations.isEmpty()) {

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

@@ -43,6 +43,25 @@ void printSum(Object obj) {
         );
     }
 
+    @Test
+    void shouldParseRecordPatternWithVarKeyword() {
+        rewriteRun(
+          java(
+            //language=java
+            """
+              record Point(int x, int y) {}
+              class Test {
+                  void printSum(Object obj) {
+                      if (obj instanceof Point(var x, var y)) {
+                          System.out.println(x + y);
+                      }
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void shouldParseJava21NestedPatternMatchForRecords() {
         rewriteRun(