text: /*
   * Copyright 2002-2019 the original author or authors.
   *
   * 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
   *
   *      https://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 org.springframework.instrument.classloading;
  
  import java.lang.instrument.ClassFileTransformer;
  import java.security.ProtectionDomain;
  
  import org.junit.jupiter.api.Test;
  
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
  import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
  
  /**
   * Unit tests for the {@link ReflectiveLoadTimeWeaver} class.
   *
   * @author Rick Evans
   * @author Chris Beams
   */
  public class ReflectiveLoadTimeWeaverTests {
  
  	@Test
  	public void testCtorWithNullClassLoader() {
  		assertThatIllegalArgumentException().isThrownBy(() ->
  				new ReflectiveLoadTimeWeaver(null));
  	}
  
  	@Test
  	public void testCtorWithClassLoaderThatDoesNotExposeAnAddTransformerMethod() {
  		assertThatIllegalStateException().isThrownBy(() ->
  				new ReflectiveLoadTimeWeaver(getClass().getClassLoader()));
  	}
  
  	@Test
  	public void testCtorWithClassLoaderThatDoesNotExposeAGetThrowawayClassLoaderMethodIsOkay() {
  		JustAddTransformerClassLoader classLoader = new JustAddTransformerClassLoader();
  		ReflectiveLoadTimeWeaver weaver = new ReflectiveLoadTimeWeaver(classLoader);
  		weaver.addTransformer(new ClassFileTransformer() {
  			@Override
  			public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) {
  				return "CAFEDEAD".getBytes();
  			}
  		});
  		assertThat(classLoader.getNumTimesGetThrowawayClassLoaderCalled()).isEqualTo(1);
  	}
  
  	@Test
  	public void testAddTransformerWithNullTransformer() {
  		assertThatIllegalArgumentException().isThrownBy(() ->
  				new ReflectiveLoadTimeWeaver(new JustAddTransformerClassLoader()).addTransformer(null));
  	}
  
  	@Test
  	public void testGetThrowawayClassLoaderWithClassLoaderThatDoesNotExposeAGetThrowawayClassLoaderMethodYieldsFallbackClassLoader() {
  		ReflectiveLoadTimeWeaver weaver = new ReflectiveLoadTimeWeaver(new JustAddTransformerClassLoader());
  		ClassLoader throwawayClassLoader = weaver.getThrowawayClassLoader();
  		assertThat(throwawayClassLoader).isNotNull();
  	}
  
  	@Test
  	public void testGetThrowawayClassLoaderWithTotallyCompliantClassLoader() {
  		TotallyCompliantClassLoader classLoader = new TotallyCompliantClassLoader();
  		ReflectiveLoadTimeWeaver weaver = new ReflectiveLoadTimeWeaver(classLoader);
  		ClassLoader throwawayClassLoader = weaver.getThrowawayClassLoader();
  		assertThat(throwawayClassLoader).isNotNull();
  		assertThat(classLoader.getNumTimesGetThrowawayClassLoaderCalled()).isEqualTo(1);
  	}
  
  
  	public static class JustAddTransformerClassLoader extends ClassLoader {
  
  		private int numTimesAddTransformerCalled = 0;
  
  
  		public int getNumTimesGetThrowawayClassLoaderCalled() {
  			return this.numTimesAddTransformerCalled;
  		}
  
  
  		public void addTransformer(ClassFileTransformer transformer) {
  			++this.numTimesAddTransformerCalled;
  		}
  
  	}
  
  
  	public static final class TotallyCompliantClassLoader extends JustAddTransformerClassLoader {
  
  		private int numTimesGetThrowawayClassLoaderCalled = 0;
  
  
  		@Override
  		public int getNumTimesGetThrowawayClassLoaderCalled() {
  			return this.numTimesGetThrowawayClassLoaderCalled;
  		}
  
  
  		public ClassLoader getThrowawayClassLoader() {
  			++this.numTimesGetThrowawayClassLoaderCalled;
  			return getClass().getClassLoader();
  		}
  
  	}
  
  }
  