001package org.junit.runner.manipulation;
002
003import java.util.Collection;
004import java.util.Collections;
005import java.util.HashSet;
006import java.util.List;
007import java.util.Set;
008
009import org.junit.runner.Description;
010
011/**
012 * Orders tests.
013 *
014 * @since 4.13
015 */
016public final class Orderer  {
017    private final Ordering ordering;
018
019    Orderer(Ordering delegate) {
020        this.ordering = delegate;
021    }
022
023    /**
024     * Orders the descriptions.
025     *
026     * @return descriptions in order
027     */
028    public List<Description> order(Collection<Description> descriptions)
029            throws InvalidOrderingException {
030        List<Description> inOrder = ordering.orderItems(
031                Collections.unmodifiableCollection(descriptions));
032        if (!ordering.validateOrderingIsCorrect()) {
033            return inOrder;
034        }
035
036        Set<Description> uniqueDescriptions = new HashSet<Description>(descriptions);
037        if (!uniqueDescriptions.containsAll(inOrder)) {
038            throw new InvalidOrderingException("Ordering added items");
039        }
040        Set<Description> resultAsSet = new HashSet<Description>(inOrder);
041        if (resultAsSet.size() != inOrder.size()) {
042            throw new InvalidOrderingException("Ordering duplicated items");
043        } else if (!resultAsSet.containsAll(uniqueDescriptions)) {
044            throw new InvalidOrderingException("Ordering removed items");
045        }
046
047        return inOrder;
048    }
049
050    /**
051     * Order the tests in <code>target</code>.
052     *
053     * @throws InvalidOrderingException if ordering does something invalid (like remove or add
054     * children)
055     */
056    public void apply(Object target) throws InvalidOrderingException {
057        if (target instanceof Orderable) {
058            Orderable orderable = (Orderable) target;
059            orderable.order(this);
060        }
061    }
062}