MetadataIndexTest.java

package net.glowstone.entity;

import net.glowstone.entity.meta.MetadataIndex;
import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

import static org.junit.Assert.*;

/**
 * Tests for {@link MetadataIndex}.
 */
public class MetadataIndexTest {

    /**
     * Tests that more specific metadata always appears later.
     */
    @Test
    public void testOrdering() {
        HashMap<Class<?>, MetadataIndex> seen = new HashMap<>();

        for (MetadataIndex index : MetadataIndex.values()) {
            Class<?> clazz = index.getAppliesTo();

            for (Map.Entry<Class<?>, MetadataIndex> entry : seen.entrySet()) {
                if (clazz != entry.getKey() && clazz.isAssignableFrom(entry.getKey())) {
                    fail("Index " + index + "(" + clazz.getSimpleName() + ") follows index " + entry.getValue() + "(" + entry.getKey().getSimpleName() + ") which it parents");
                }
            }

            if (!seen.containsKey(clazz)) {
                seen.put(clazz, index);
            }
        }
    }

    /**
     * Tests that no two MetadataIndex entries can overlap on a single
     * entity. Will not catch failure for entities without any metadata
     * keys defined.
     */
    @Test
    public void testNoOverlap() {
        HashMap<Class<?>, HashMap<Integer, MetadataIndex>> map = new HashMap<>();

        for (MetadataIndex index : MetadataIndex.values()) {
            Class<?> clazz = index.getAppliesTo();

            if (index == MetadataIndex.PLAYER_SKIN_FLAGS) {
                // this index is permitted to override others
                continue;
            }

            // check for duplication
            for (Map.Entry<Class<?>, HashMap<Integer, MetadataIndex>> entry : map.entrySet()) {
                // check that class is a parent
                if (entry.getKey().isAssignableFrom(clazz)) {
                    // look for matching index
                    if (entry.getValue().containsKey(index.getIndex())) {
                        fail("Index " + index + "(" + clazz.getSimpleName() + ") conflicts with " + entry.getValue().get(index.getIndex()) + "(" + entry.getKey().getSimpleName() + ")");
                    }
                }
            }

            // insert this index
            HashMap<Integer, MetadataIndex> classMap = map.get(index.getAppliesTo());
            if (classMap == null) {
                classMap = new HashMap<>();
                map.put(index.getAppliesTo(), classMap);
            }
            classMap.put(index.getIndex(), index);
        }
    }

}