SequentialEntryIterableMatchers.java

/*
 * Copyright 2014 WANdisco
 *
 *  WANdisco licenses this file to you under the Apache License,
 *  version 2.0 (the "License"); you may not use this file except in compliance
 *  with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 *  License for the specific language governing permissions and limitations
 *  under the License.
 */

package c5db.interfaces.log;

import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;

import java.util.List;

import static c5db.interfaces.log.SequentialEntryIterable.SequentialEntryIterator;

public class SequentialEntryIterableMatchers {
  public static <E extends SequentialEntry> TypeSafeMatcher<SequentialEntryIterator<E>>
  isIteratorContainingInOrder(List<E> entries) {

    return new TypeSafeMatcher<SequentialEntryIterator<E>>() {
      private Exception exception;

      @Override
      protected boolean matchesSafely(SequentialEntryIterator<E> iterator) {
        int listIndex = 0;

        try {
          while (iterator.hasNext()) {
            E next = iterator.next();
            if (listIndex >= entries.size()
                || !next.equals(entries.get(listIndex))) {
              return false;
            }

            listIndex++;
          }
        } catch (Exception e) {
          exception = e;
          return false;
        }

        return listIndex == entries.size();
      }

      @Override
      public void describeTo(Description description) {
        description.appendText(" a SequentialEntryIterator containing, in order, ")
            .appendValue(entries);
      }

      @Override
      protected void describeMismatchSafely(SequentialEntryIterator<E> item, Description mismatchDescription) {
        if (exception != null) {
          mismatchDescription.appendValue(exception);
        } else {
          super.describeMismatchSafely(item, mismatchDescription);
        }
      }
    };
  }
}