FieldMatcher.java

/*
 * Copyright (c) 2002 Cunningham & Cunningham, Inc.
 * Copyright (c) 2009-2015 by Jochen Wierum & Cologne Intelligence
 *
 * This file is part of FitGoodies.
 *
 * FitGoodies is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * FitGoodies is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with FitGoodies.  If not, see <http://www.gnu.org/licenses/>.
 */

package de.cologneintelligence.fitgoodies.testsupport;

import org.hamcrest.Description;
import org.hamcrest.DiagnosingMatcher;
import org.hamcrest.Matcher;

import java.lang.reflect.Field;

public class FieldMatcher extends DiagnosingMatcher<Object> {
	private final String fieldName;
	private final Matcher matcher;

	public FieldMatcher(String fieldName, Matcher matcher) {
		this.fieldName = fieldName;
		this.matcher = matcher;
	}

	public static FieldMatcher hasField(String name, Matcher matcher) {
		return new FieldMatcher(name, matcher);
	}

	@Override
	public boolean matches(final Object item, Description mismatchDescription) {
		try {
			final Field fieldItem = item.getClass().getField(fieldName);
			final Object fieldObjectItem = fieldItem.get(item);

			if (matcher.matches(fieldObjectItem)) {
				return true;
			}

			matcher.describeMismatch(fieldObjectItem, mismatchDescription);

		} catch (IllegalAccessException e) {
			mismatchDescription.appendText("is inaccessible");
		} catch (NoSuchFieldException e) {
			mismatchDescription.appendText("doesn't exist");
		}

		return false;
	}

	@Override
	public void describeTo(final Description description) {
		description.appendText("Field " + fieldName + " that ");
		matcher.describeTo(description);
	}
}