Handle 'any' patterns

Fixes google#1037

PiperOrigin-RevId: 606394473

core/src/main/java/com/google/googlejavaformat/java/java21/Java21InputAstVisitor.java

@@ -24,6 +24,8 @@
 import com.sun.source.tree.PatternCaseLabelTree;
 import com.sun.source.tree.PatternTree;
 import com.sun.source.tree.StringTemplateTree;
+import com.sun.source.tree.Tree;
+import com.sun.tools.javac.tree.JCTree;
 import javax.lang.model.element.Name;
 
 /**
@@ -107,4 +109,20 @@ protected void variableName(Name name) {
       visit(name);
     }
   }
+
+  @Override
+  public Void scan(Tree tree, Void unused) {
+    // Pre-visit AST for preview features, since com.sun.source.tree.AnyPattern can't be
+    // accessed directly without --enable-preview.
+    if (tree instanceof JCTree.JCAnyPattern) {
+      visitJcAnyPattern((JCTree.JCAnyPattern) tree);
+      return null;
+    } else {
+      return super.scan(tree, unused);
+    }
+  }
+
+  private void visitJcAnyPattern(JCTree.JCAnyPattern unused) {
+    token("_");
+  }
 }

core/src/test/java/com/google/googlejavaformat/java/FormatterIntegrationTest.java

@@ -62,7 +62,8 @@ public class FormatterIntegrationTest {
               "Unnamed",
               "I981",
               "StringTemplate",
-              "I1020")
+              "I1020",
+              "I1037")
           .build();
 
   @Parameters(name = "{index}: {0}")

core/src/test/resources/com/google/googlejavaformat/java/testdata/I1037.input

@@ -0,0 +1,11 @@
+public sealed interface A {
+  record AA(Long a) implements A {}
+
+  static Long mySwitch(A a) {
+    switch (a) {
+      case AA(_) -> {
+        return 1L;
+      }
+    }
+  }
+}

core/src/test/resources/com/google/googlejavaformat/java/testdata/I1037.output

@@ -0,0 +1,11 @@
+public sealed interface A {
+  record AA(Long a) implements A {}
+
+  static Long mySwitch(A a) {
+    switch (a) {
+      case AA(_) -> {
+        return 1L;
+      }
+    }
+  }
+}