AssertThatException.java

/**
 * Powerunit - A JDK1.8 test framework
 * Copyright (C) 2014 Mathieu Boretti.
 *
 * This file is part of Powerunit
 *
 * Powerunit 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.
 *
 * Powerunit 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 Powerunit. If not, see <http://www.gnu.org/licenses/>.
 */
package ch.powerunit;

import org.hamcrest.Matcher;

/**
 * DSL for assertion on exception result.
 * <p>
 * This interface is returned by the various methods
 * {@link TestSuite#assertWhen(Statement) assertWhen} exposed by
 * {@link TestSuite}.
 *
 * @author borettim
 *
 * @param <T>
 *            The exception type
 */
public interface AssertThatException<T extends Throwable> {

	/**
	 * Define the matcher on the exception and execute the matcher validation.
	 * <p>
	 * <br>
	 * <i>By default, assertion can only be used from the main thread of the
	 * test ; When used from another thread, the assertion will be lost. In the
	 * case the {@link Test#fastFail() fastFail} attribute of {@link Test @Test}
	 * annotation is used, the assertion may not be lost, in case the thread use
	 * an assertion method from the test object instance. </i>
	 * <p>
	 * For instance, having this method :
	 * 
	 * <pre>
	 * public static void method1() throws Exception {
	 * 	throw new Exception("demo1");
	 * }
	 * </pre>
	 * 
	 * It is possible to test the message by using :
	 * 
	 * <pre>
	 * assertWhen(asStatement(DemoAssertThatExceptionTest::method1)).throwException(
	 * 		exceptionMessage("demo1"));
	 * </pre>
	 * 
	 * @param matching
	 *            the matcher.
	 * @return true if the assertion is valid ; If the assertion is false,
	 *         depending on {@link Test#fastFail()} : If <code>true</code>, then
	 *         fail the test, else, return false and the test will be failed
	 *         later.
	 * @see Test#fastFail() The documentation of the <code>fastFail</code>
	 *      attribute of the <code>@Test</code> annotation, regarding the action
	 *      done by this assertion.
	 */
	boolean throwException(Matcher<? super T> matching);
}