Issue #1036: Adding unit test

Author: DPUkyle

guice/src/test/java/cucumber/runtime/java/guice/impl/InjectorSourceFactoryTest.java

@@ -3,8 +3,15 @@
 import com.google.inject.Injector;
 import cucumber.runtime.Env;
 import cucumber.runtime.java.guice.InjectorSource;
+import org.junit.Assert;
 import org.junit.Test;
 
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.net.URL;
+import java.net.URLClassLoader;
 import java.util.Properties;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -110,4 +117,62 @@ public void failsToInstantiateClassWithNoDefaultConstructor() throws Exception {
             assertThat(exception.getCause(), instanceOf(InstantiationException.class));
         }
     }
+
+  /**
+   * <p>Simulates enterprise applications which often use a hierarchy of classloaders.
+   * 
+   * <p>MyChildClassLoader is the only classloader with knowledge of c.r.j.guice.impl.LivesInChildClassLoader
+   * 
+   * <p>The bytecode of LivesInChildClassLoader is intentionally renamed to 'LivesInChildClassLoader.class.txt' to prevent
+   * this test's ClassLoader from resolving it.
+   * 
+   * <p>If InjectorSourceFactory calls Class#forName without an explicit ClassLoader argument, which is the behavior of 
+   * 1.2.4 and earlier, Class#forName will default to the test's ClassLoader which has no knowledge 
+   * of class LivesInChildClassLoader and the test will fail.
+   * 
+   * <p>See <a href="https://github.com/cucumber/cucumber-jvm/issues/1036">https://github.com/cucumber/cucumber-jvm/issues/1036</a>
+   * @throws Exception
+   */
+  @Test
+    public void instantiateClassInChildClassLoader() throws Exception {
+        ClassLoader childClassLoader = new MyChildClassLoader(this.getClass().getClassLoader());
+        Thread.currentThread().setContextClassLoader( childClassLoader );
+        
+        Properties properties = new Properties();
+        properties.setProperty(InjectorSourceFactory.GUICE_INJECTOR_SOURCE_KEY, "cucumber.runtime.java.guice.impl.LivesInChildClassLoader");
+        InjectorSourceFactory injectorSourceFactory = createInjectorSourceFactory(properties);
+        
+        assertThat(injectorSourceFactory.create(), is(instanceOf(InjectorSource.class)));        
+    }
+    
+    private static class MyChildClassLoader extends ClassLoader {
+        public MyChildClassLoader( ClassLoader parent ) {
+            super(parent);
+        }
+
+        @Override
+        protected Class<?> loadClass( String name, boolean resolve ) throws ClassNotFoundException {
+            if( name.equals( "cucumber.runtime.java.guice.impl.LivesInChildClassLoader" ) ) {
+                String filename = getClass().getClassLoader().getResource("cucumber/runtime/java/guice/impl/LivesInChildClassLoader.class.txt").getFile();
+                File file = new File( filename );
+                try {
+                    FileInputStream in = new FileInputStream( file );
+                    byte[] bytes = new byte[1024];
+                    ByteArrayOutputStream content = new ByteArrayOutputStream();
+                    while( true ) {
+                        int iLen = in.read(bytes);
+                        content.write( bytes, 0, iLen );
+                        if( iLen < 1024 ) {
+                            break;
+                        }
+                    }
+                    byte[] bytecode = content.toByteArray();
+                    return defineClass( name, bytecode, 0, bytecode.length );
+                } catch (Exception e) {
+                    throw new RuntimeException( e );
+                }
+            }
+            return super.loadClass(name, resolve);
+        }
+    }
 }

guice/src/test/resources/cucumber/runtime/java/guice/impl/LivesInChildClassLoader.class.txt

@@ -0,0 +1,11 @@
+package cucumber.runtime.java.guice.impl;
+
+import com.google.inject.Injector;
+import cucumber.runtime.java.guice.InjectorSource;
+
+public class LivesInChildClassLoader implements InjectorSource {
+  @Override
+  public Injector getInjector() {
+    return null;
+  }
+}