1 /*

     2  * @test /nodynamiccopyright/

     3  * @bug 8206986

     4  * @summary Verify cases with multiple labels work properly.

     5  * @compile/fail/ref=MultipleLabelsExpression-old.out -source 9 -Xlint:-options -XDrawDiagnostics MultipleLabelsExpression.java

     6  * @compile --enable-preview -source 12 MultipleLabelsExpression.java

     7  * @run main/othervm --enable-preview MultipleLabelsExpression

     8  */

     9 

    10 import java.util.Objects;

    11 import java.util.function.Function;

    12 

    13 public class MultipleLabelsExpression {

    14     public static void main(String... args) {

    15         new MultipleLabelsExpression().run();

    16     }

    17 

    18     private void run() {

    19         runTest(this::expression1);

    20     }

    21 

    22     private void runTest(Function<T, String> print) {

    23         check(T.A,  print, "A");

    24         check(T.B,  print, "B-C");

    25         check(T.C,  print, "B-C");

    26         check(T.D,  print, "D");

    27         check(T.E,  print, "other");

    28     }

    29 

    30     private String expression1(T t) {

    31         return switch (t) {

    32             case A -> "A";

    33             case B, C -> { break "B-C"; }

    34             case D -> "D";

    35             default -> "other";

    36         };

    37     }

    38 

    39     private void check(T t, Function<T, String> print, String expected) {

    40         String result = print.apply(t);

    41         if (!Objects.equals(result, expected)) {

    42             throw new AssertionError("Unexpected result: " + result);

    43         }

    44     }

    45 

    46     enum T {

    47         A, B, C, D, E;

    48     }

    49 }