Add deletion check to test

* adds test if deleted files really don't exist anymore afterwards
* adds boolean isDeleted(String path) function to Deleter interface
* other Uploaders must implement this method, otherwise
NotImplementedException is thrown when running this test

pom.xml

@@ -141,5 +141,11 @@ Institute of Molecular Cell Biology and Genetics.</license.copyrightOwners>
 			<classifier>tests</classifier>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>commons-lang</groupId>
+			<artifactId>commons-lang</artifactId>
+			<version>2.6</version>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 </project>

src/test/java/net/imagej/updater/AbstractUploaderTestBase.java

@@ -31,24 +31,21 @@
 
 package net.imagej.updater;
 
-import static net.imagej.updater.UpdaterTestUtils.cleanup;
-import static net.imagej.updater.UpdaterTestUtils.initialize;
-import static net.imagej.updater.UpdaterTestUtils.writeFile;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assume.assumeNotNull;
+import net.imagej.updater.util.StderrProgress;
+import net.imagej.updater.util.UpdaterUtil;
+import org.apache.commons.lang.NotImplementedException;
+import org.junit.After;
 
 import java.io.File;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URL;
 
-import net.imagej.updater.FilesCollection;
-import net.imagej.updater.util.StderrProgress;
-import net.imagej.updater.util.UpdaterUtil;
-
-import org.junit.After;
+import static net.imagej.updater.UpdaterTestUtils.*;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeNotNull;
 
 /**
  * An abstract base class for testing uploader backends.
@@ -87,6 +84,8 @@ public void test(final Deleter deleter, final String host, final String uploadDi
 			assertTrue(deleter.login());
 			deleter.delete(UpdaterUtil.XML_COMPRESSED);
 			deleter.delete("plugins/");
+			assertTrue(deleter.isDeleted(UpdaterUtil.XML_COMPRESSED));
+			assertTrue(deleter.isDeleted("plugins/"));
 			deleter.logout();
 		}
 
@@ -144,8 +143,11 @@ public boolean isUpdateSiteEmpty() throws MalformedURLException, IOException {
 	}
 
 	public interface Deleter {
-		public abstract boolean login();
-		public abstract void delete(final String path) throws IOException;
-		public abstract void logout();
+		boolean login();
+		void delete(final String path) throws IOException;
+		void logout();
+		default boolean isDeleted(String path) throws IOException {
+			throw new NotImplementedException();
+		}
 	}
 }