EnumValue.java

import org.checkerframework.common.value.qual.*;

public class EnumValue {

    enum Direction {
        NORTH,
        WEST,
        SOUTH,
        EAST
    };

    public enum Color {
        BLUE,
        RED,
        GREEN
    };

    private enum Fruit {
        APPLE,
        ORANGE,
        PEAR
    };

    void simpleTest() {
        Direction @ArrayLen(4) [] myCompass = Direction.values();
        Color @ArrayLen(3) [] myColors = Color.values();
        Fruit @ArrayLen(3) [] myFruitBasket = Fruit.values();

        //:: error: (assignment.type.incompatible)
        Direction @ArrayLen(7) [] badCompass = Direction.values();

        //:: error: (assignment.type.incompatible)
        Color @ArrayLen(4) [] badColors = Color.values();

        //:: error: (assignment.type.incompatible)
        Fruit @ArrayLen(2) [] badFruit = Fruit.values();
    }

    public enum AdvDirection {
        ANORTH {
            public AdvDirection getOpposite() {
                return ASOUTH;
            }
        },
        AEAST {
            public AdvDirection getOpposite() {
                return AWEST;
            }
        },
        ASOUTH {
            public AdvDirection getOpposite() {
                return ANORTH;
            }
        },
        AWEST {
            public AdvDirection getOpposite() {
                return AEAST;
            }
        };

        public abstract AdvDirection getOpposite();
    }

    void advTest() {
        AdvDirection @ArrayLen(4) [] myCompass = AdvDirection.values();
        //:: error: (assignment.type.incompatible)
        AdvDirection @ArrayLen(3) [] badCompass = AdvDirection.values();
        //:: error: (assignment.type.incompatible)
        AdvDirection @ArrayLen(5) [] badCompass2 = AdvDirection.values();
    }
}