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The goal of quality-test is to provide a small Java library for basic code quality checks within unit tests. It is discouraged to use quality-test in production code. The checks provided in this library are designed to be used in unit-tests. The checks and utilities provided in this package check static properties of classes, for example whether classes are marked final or constructors are private. Additionally, there are utils to give additional code coverage for private constructors. Quality-Test often can be used together with Google Reflections (http://code.google.com/p/reflections/) to perform checks such as, assure that every class in package *.dto.* is final or make sure that no class in the package *.controller.* contains any non-final static variables.

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/*******************************************************************************
 * Copyright 2013 André Rouél
 * Copyright 2013 Dominik Seichter
 * 
 * Licensed 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 net.sf.qualitytest;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;

import javax.annotation.Nonnull;

import net.sf.qualitytest.exception.CoverageForPrivateConstructorException;

/**
 * Code coverage often report missing line coverage if your utility classes
 * contain private constructors. Still, it is good practice to assure
 * that utility classes cannot be constructed. This utility class
 * will execute a private default constructor in a class and therefore
 * remove this noise from your code coverage reports.
 *  
 * @author Dominik Seichter
 *
 */
public final class CoverageForPrivateConstructor {

	/**
	 * Reduce noise in code coverage reports by
	 * executing the private default constructor of 
	 * a utility class.
	 * 
	 * @param clazz The private default constructor of this class is executed.
	 */
	public static void giveMeCoverage(@Nonnull final Class clazz) {
		// reduces only some noise in coverage report
		try {
			giveMeCoverageInteral(clazz);
		} catch (SecurityException e) {
			throw new CoverageForPrivateConstructorException(e);
		} catch (NoSuchMethodException e) {
			throw new CoverageForPrivateConstructorException(e);
		} catch (IllegalArgumentException e) {
			throw new CoverageForPrivateConstructorException(e);
		} catch (InstantiationException e) {
			throw new CoverageForPrivateConstructorException(e);
		} catch (IllegalAccessException e) {
			throw new CoverageForPrivateConstructorException(e);
		} catch (InvocationTargetException e) {
			throw new CoverageForPrivateConstructorException(e);
		}		
	}

	/**
	 * Internal method which we can mock to simulate different exceptions.
	 * 
	 * @param clazz
	 * @throws NoSuchMethodException
	 * @throws InstantiationException
	 * @throws IllegalAccessException
	 * @throws InvocationTargetException
	 */
	protected static void giveMeCoverageInteral(@Nonnull final Class clazz)
			throws NoSuchMethodException, InstantiationException,
			IllegalAccessException, InvocationTargetException {
		final Constructor constructor = clazz.getDeclaredConstructor();
		constructor.setAccessible(true);
		constructor.newInstance();
		constructor.setAccessible(false);
	}
	
	
	
	/**
	 * Attention: This class is not intended to create objects from it.
	 */
	private CoverageForPrivateConstructor() {
		// This class is not intended to create objects from it.
	}
}