TMS-29: Test case exposing .ConcurrentModificationException.

servlet/src/test/java/com/twelvemonkeys/servlet/image/IIOProviderContextListenerTest.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2014, Harald Kuhr
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name "TwelveMonkeys" nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.twelvemonkeys.servlet.image;
+
+import org.junit.Test;
+
+import javax.imageio.ImageReader;
+import javax.imageio.spi.IIORegistry;
+import javax.imageio.spi.ImageReaderSpi;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+import java.io.IOException;
+import java.util.Locale;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * IIOProviderContextListenerTest
+ *
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
+ * @author last modified by $Author: haraldk$
+ * @version $Id: IIOProviderContextListenerTest.java,v 1.0 02.01.14 12:33 haraldk Exp$
+ */
+public class IIOProviderContextListenerTest {
+    @Test
+    public void testContextInitialized() {
+        ServletContextListener listener = new IIOProviderContextListener();
+        listener.contextInitialized(mock(ServletContextEvent.class));
+    }
+
+    @Test
+    public void testContextDestroyed() {
+        ServletContext context = mock(ServletContext.class);
+        ServletContextEvent destroyed = mock(ServletContextEvent.class);
+        when(destroyed.getServletContext()).thenReturn(context);
+
+        ServletContextListener listener = new IIOProviderContextListener();
+        listener.contextInitialized(mock(ServletContextEvent.class));
+        listener.contextDestroyed(destroyed);
+    }
+
+    // Regression test for issue #30
+    @Test
+    public void testDestroyConcurrentModRegression() {
+        ServletContext context = mock(ServletContext.class);
+        ServletContextEvent destroyed = mock(ServletContextEvent.class);
+        when(destroyed.getServletContext()).thenReturn(context);
+
+        ServletContextListener listener = new IIOProviderContextListener();
+        listener.contextInitialized(mock(ServletContextEvent.class));
+
+        ImageReaderSpi provider1 = new MockImageReaderSpiOne();
+        ImageReaderSpi provider2 = new MockImageReaderSpiToo();
+
+        // NOTE: Fake registering for simplicity, but it still exposes the original problem with de-registering
+        IIORegistry registry = IIORegistry.getDefaultInstance();
+        registry.registerServiceProvider(provider1);
+        registry.registerServiceProvider(provider2);
+        assertTrue(registry.contains(provider1));
+        assertTrue(registry.contains(provider2));
+
+        listener.contextDestroyed(destroyed);
+
+        assertFalse(registry.contains(provider1));
+        assertFalse(registry.contains(provider2));
+    }
+
+    private static abstract class MockImageReaderSpiBase extends ImageReaderSpi {
+        @Override
+        public boolean canDecodeInput(Object source) throws IOException {
+            return false;
+        }
+
+        @Override
+        public ImageReader createReaderInstance(Object extension) throws IOException {
+            return null;
+        }
+
+        @Override
+        public String getDescription(Locale locale) {
+            return "I'm a mock. So don't mock me.";
+        }
+    }
+
+    private static final class MockImageReaderSpiOne extends MockImageReaderSpiBase {
+    }
+
+    private static final class MockImageReaderSpiToo extends MockImageReaderSpiBase {
+    }
+}