Fix formatting records without an explicit constructor

palantir-java-format/src/main/java/com/palantir/javaformat/java/JavaInputAstVisitor.java

@@ -1369,6 +1369,8 @@ public Void visitAnnotatedType(AnnotatedTypeTree node, Void unused) {
     // TODO(fawind): Use Flags.COMPACT_RECORD_CONSTRUCTOR once if/when we drop support for Java 11
     protected static final long COMPACT_RECORD_CONSTRUCTOR = 1L << 51;
 
+    protected static final long RECORD = 1L << 61;
+
     @Override
     public Void visitMethod(MethodTree node, Void unused) {
         sync(node);

palantir-java-format/src/main/java/com/palantir/javaformat/java/java14/Java14InputAstVisitor.java

@@ -17,10 +17,11 @@
 package com.palantir.javaformat.java.java14;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
-import static com.google.common.collect.MoreCollectors.onlyElement;
+import static com.google.common.collect.MoreCollectors.toOptional;
 import static com.sun.source.tree.Tree.Kind.BLOCK;
 
 import com.google.common.base.Verify;
+import com.google.common.collect.ImmutableList;
 import com.palantir.javaformat.Op;
 import com.palantir.javaformat.OpsBuilder;
 import com.palantir.javaformat.java.JavaInputAstVisitor;
@@ -29,13 +30,11 @@
 import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.InstanceOfTree;
-import com.sun.source.tree.MethodTree;
 import com.sun.source.tree.SwitchExpressionTree;
 import com.sun.source.tree.Tree;
 import com.sun.source.tree.YieldTree;
 import com.sun.tools.javac.code.Flags;
 import com.sun.tools.javac.tree.JCTree;
-import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
 import com.sun.tools.javac.tree.TreeInfo;
 import java.util.List;
 import java.util.Optional;
@@ -111,17 +110,16 @@ public void visitRecordDeclaration(ClassTree node) {
             if (!node.getTypeParameters().isEmpty()) {
                 typeParametersRest(node.getTypeParameters(), hasSuperInterfaceTypes ? plusFour : ZERO);
             }
-            MethodTree constructor = node.getMembers().stream()
-                    .filter(JCMethodDecl.class::isInstance)
-                    .map(JCMethodDecl.class::cast)
-                    .filter(m -> (m.mods.flags & COMPACT_RECORD_CONSTRUCTOR) == COMPACT_RECORD_CONSTRUCTOR)
-                    .collect(onlyElement());
+            ImmutableList<JCTree.JCVariableDecl> parameters = compactRecordConstructor(node)
+                    .map(m -> ImmutableList.copyOf(m.getParameters()))
+                    .orElseGet(() -> recordVariables(node));
             token("(");
-            if (!constructor.getParameters().isEmpty() || constructor.getReceiverParameter() != null) {
+            if (!parameters.isEmpty()) {
                 // Break before args.
                 builder.breakToFill("");
             }
-            visitFormals(Optional.ofNullable(constructor.getReceiverParameter()), constructor.getParameters());
+            // record headers can't declare receiver parameters
+            visitFormals(/* receiver= */ Optional.empty(), parameters);
             token(")");
             if (hasSuperInterfaceTypes) {
                 builder.breakToFill(" ");
@@ -152,6 +150,22 @@ public void visitRecordDeclaration(ClassTree node) {
         dropEmptyDeclarations();
     }
 
+    private static Optional<JCTree.JCMethodDecl> compactRecordConstructor(ClassTree node) {
+        return node.getMembers().stream()
+                .filter(JCTree.JCMethodDecl.class::isInstance)
+                .map(JCTree.JCMethodDecl.class::cast)
+                .filter(m -> (m.mods.flags & COMPACT_RECORD_CONSTRUCTOR) == COMPACT_RECORD_CONSTRUCTOR)
+                .collect(toOptional());
+    }
+
+    private static ImmutableList<JCTree.JCVariableDecl> recordVariables(ClassTree node) {
+        return node.getMembers().stream()
+                .filter(JCTree.JCVariableDecl.class::isInstance)
+                .map(JCTree.JCVariableDecl.class::cast)
+                .filter(m -> (m.mods.flags & RECORD) == RECORD)
+                .collect(toImmutableList());
+    }
+
     @Override
     public Void visitInstanceOf(InstanceOfTree node, Void unused) {
         sync(node);

palantir-java-format/src/test/java/com/palantir/javaformat/java/FileBasedTests.java

@@ -41,7 +41,8 @@
 @Execution(ExecutionMode.CONCURRENT)
 public final class FileBasedTests {
     // Tests files that are only used when run with java 14 or higher
-    private static final ImmutableSet<String> JAVA_14_TESTS = ImmutableSet.of("java14");
+    private static final ImmutableSet<String> JAVA_14_TESTS =
+            ImmutableSet.of("ExpressionSwitch", "RSL", "Records", "Var");
 
     private final Class<?> testClass;
     /** The path prefix for all tests if loaded as resources. */

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/ExpressionSwitch.input

@@ -0,0 +1,9 @@
+class ExpressionSwitch {
+  boolean odd(int x) {
+    return switch (x) {
+      case 0  -> true;
+      case 1  -> false;
+      default -> { int y = x - 1; return odd(y); }
+    };
+  }
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/ExpressionSwitch.output

@@ -0,0 +1,12 @@
+class ExpressionSwitch {
+    boolean odd(int x) {
+        return switch (x) {
+            case 0 -> true;
+            case 1 -> false;
+            default -> {
+                int y = x - 1;
+                return odd(y);
+            }
+        };
+    }
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/RSL.input

@@ -0,0 +1,6 @@
+class RSLs {
+    String s = """
+    lorem
+      ipsum
+    """;
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/RSL.output

@@ -0,0 +1,6 @@
+class RSLs {
+    String s = """
+    lorem
+      ipsum
+    """;
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/Records.input

@@ -0,0 +1,29 @@
+class Records {
+  record R1() {}
+
+  private record R2() {}
+
+  @Deprecated
+  private record R3() {}
+
+  record R4<T>() {}
+
+  record R5<T>(int x) {}
+
+  record R6<T>(@Deprecated int x) {}
+
+  record R7<T>(@Deprecated int x, int... y) {}
+
+  record R8<T>() implements Comparable<R8<T>> {
+    @Override
+    public int compareTo(R8<T> other) {
+      return 0;
+    }
+  }
+
+  record R9(int x) {
+    R9(int x) {
+      this.x = x;
+    }
+  }
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/Records.output

@@ -0,0 +1,29 @@
+class Records {
+    record R1() {}
+
+    private record R2() {}
+
+    @Deprecated
+    private record R3() {}
+
+    record R4<T>() {}
+
+    record R5<T>(int x) {}
+
+    record R6<T>(@Deprecated int x) {}
+
+    record R7<T>(@Deprecated int x, int... y) {}
+
+    record R8<T>() implements Comparable<R8<T>> {
+        @Override
+        public int compareTo(R8<T> other) {
+            return 0;
+        }
+    }
+
+    record R9(int x) {
+        R9(int x) {
+            this.x = x;
+        }
+    }
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/Var.input

@@ -0,0 +1,5 @@
+class Var {
+  void f() {
+    for (var x : ImmutableList.of(42)) {}
+  }
+}

palantir-java-format/src/test/resources/com/palantir/javaformat/java/testdata/Var.output

@@ -0,0 +1,5 @@
+class Var {
+    void f() {
+        for (var x : ImmutableList.of(42)) {}
+    }
+}