/*
    * Copyright (C) 2019 Nail Samatov <sanail@yandex.ru> and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  package org.eclipse.jgit.junit;
  
  import static java.lang.ClassLoader.getSystemClassLoader;
  
  import java.net.URL;
  import java.net.URLClassLoader;
  
  import org.junit.runners.BlockJUnit4ClassRunner;
  import org.junit.runners.model.InitializationError;
  
  /**
   * This class is used when it's required to load jgit classes in separate
   * classloader for each test class. It can be needed to isolate static field
   * initialization between separate tests.
   */
  public class SeparateClassloaderTestRunner extends BlockJUnit4ClassRunner {
  
  	/**
  	 * Creates a SeparateClassloaderTestRunner to run {@code klass}.
  	 *
  	 * @param klass
  	 *            test class to run.
  	 * @throws InitializationError
  	 *             if the test class is malformed or can't be found.
  	 */
  	public SeparateClassloaderTestRunner(Class<?> klass)
  			throws InitializationError {
  		super(loadNewClass(klass));
  	}
  
  	private static Class<?> loadNewClass(Class<?> klass)
  			throws InitializationError {
  		try {
  			URL[] urls = ((URLClassLoader) getSystemClassLoader()).getURLs();
  			ClassLoader testClassLoader = new URLClassLoader(urls) {
  
  				@Override
  				public Class<?> loadClass(String name)
  						throws ClassNotFoundException {
  					if (name.startsWith("org.eclipse.jgit.")) {
  						return super.findClass(name);
  					}
  
  					return super.loadClass(name);
  				}
  			};
  			return Class.forName(klass.getName(), true, testClassLoader);
  		} catch (ClassNotFoundException e) {
  			throw new InitializationError(e);
  		}
  	}
  }