mavenized testing-util module - wip

1 files changed, 978 insertions, 0 deletions

diff --git a/testing-util/src/main/java/org/aspectj/testing/util/TestUtil.java b/testing-util/src/main/java/org/aspectj/testing/util/TestUtil.java
new file mode 100644
index 000000000..1dbc0115c
--- /dev/null
+++ b/testing-util/src/main/java/org/aspectj/testing/util/TestUtil.java
@@ -0,0 +1,978 @@
+/* *******************************************************************
+ * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
+ * All rights reserved. 
+ * This program and the accompanying materials are made available 
+ * under the terms of the Eclipse Public License v1.0 
+ * which accompanies this distribution and is available at 
+ * http://www.eclipse.org/legal/epl-v10.html 
+ *  
+ * Contributors: 
+ *     Xerox/PARC     initial implementation 
+ * ******************************************************************/
+
+package org.aspectj.testing.util;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.io.PrintWriter;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+
+import jdiff.text.FileLine;
+import jdiff.util.Diff;
+import jdiff.util.DiffNormalOutput;
+import junit.framework.Assert;
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestResult;
+import junit.framework.TestSuite;
+import junit.runner.TestCaseClassLoader;
+
+import org.aspectj.bridge.IMessageHandler;
+import org.aspectj.bridge.MessageUtil;
+import org.aspectj.util.FileUtil;
+import org.aspectj.util.LangUtil;
+import org.aspectj.util.Reflection;
+
+/**
+ * Things that junit should perhaps have, but doesn't. Note the file-comparison methods require JDiff to run, but JDiff types are
+ * not required to resolve this class. Also, the bytecode weaver is required to compare class files, but not to compare other files.
+ */
+public final class TestUtil {
+	private static final boolean JAVA_5_VM;
+	private static final String ASPECTJRT_KEY = "aspectjrt";
+	private static final String TESTING_CLIENT_KEY = "testing-client";
+	public static final URL BAD_URL;
+	private static final File LIB_DIR;
+	private static final Properties LIB_RPATHS;
+	private static final Map LIB_ENTRIES;
+	private static File ASPECTJRT_PATH;
+	static {
+		{
+			String[] paths = { "sp:aspectjrt.path", "sp:aspectjrt.jar", "../lib/test/aspectjrt.jar",
+					"../aj-build/jars/aspectj5rt-all.jar", "../aj-build/jars/runtime.jar", "../runtime/bin" };
+			ASPECTJRT_PATH = FileUtil.getBestFile(paths);
+		}
+		{
+			boolean j5 = false;
+			try {
+				Class.forName("java.lang.annotation.Annotation");
+				j5 = true;
+			} catch (Throwable t) {
+			}
+			JAVA_5_VM = j5;
+		}
+		{
+			URL url = null;
+			try {
+				url = new URL("http://eclipse.org/BADURL");
+			} catch (MalformedURLException e) {
+				// ignore - hopefully never
+			}
+			BAD_URL = url;
+		}
+		{
+			File file = new File("lib");
+			if (!isLibDir(file)) {
+				File cur = new File(".").getAbsoluteFile();
+				File parent = cur.getParentFile();
+				while (null != parent) {
+					file = new File(parent, "lib");
+					if (isLibDir(file)) {
+						break;
+					}
+					parent = parent.getParentFile();
+				}
+				if (null == parent) {
+					file = new File("NOT IN ASPECTJ TREE");
+				}
+			}
+			LIB_DIR = file;
+		}
+
+		LIB_RPATHS = new Properties();
+		LIB_RPATHS.setProperty(ASPECTJRT_KEY, "tests/aspectjrt.jar");
+		LIB_RPATHS.setProperty(TESTING_CLIENT_KEY, "tests/testing-client.jar");
+		// TODO support others loaded dynamically
+
+		Map map = new HashMap();
+		for (Iterator iter = LIB_RPATHS.keySet().iterator(); iter.hasNext();) {
+			String key = (String) iter.next();
+			String path = LIB_RPATHS.getProperty(key);
+			File file = null;
+			URL url = null;
+			try {
+				file = libFile(path);
+				url = libURL(path);
+			} catch (IllegalArgumentException e) {
+				file = new File(path + " not found");
+				url = BAD_URL;
+			} finally {
+				map.put(key + ".file", file);
+				map.put(key + ".url", url);
+			}
+		}
+		// TODO support changing entries, etc.
+		LIB_ENTRIES = Collections.unmodifiableMap(map);
+	}
+
+	private static boolean isLibDir(File lib) {
+		return new File(lib, "test" + File.separator + "aspectjrt.jar").exists();
+	}
+
+	private TestUtil() {
+		super();
+	}
+
+	public static boolean is15VMOrGreater() {
+		return JAVA_5_VM;
+	}
+
+	public static File aspectjrtPath() {
+		return ASPECTJRT_PATH;
+	}
+
+	public static URL fileToURL(File file) {
+		try {
+			return file.toURL();
+		} catch (MalformedURLException e) {
+			return null;
+		}
+	}
+
+	public static String filesToPath(File[] entries) {
+		return toPath(entries);
+	}
+
+	public static String urlsToPath(URL[] entries) {
+		return toPath(entries);
+	}
+
+	/**
+	 * untyped interface for mixed entries
+	 */
+	public static String filesOrurlsToPath(Object[] entries) {
+		return toPath(entries);
+	}
+
+	/**
+	 * This relies on these being File (where toString() == getPath()) or URL (where toString() == toExternalForm()).
+	 * 
+	 * @param entries the Object[] of File or URL elements
+	 * @return the String with entries dlimited by the File.pathSeparator
+	 */
+	private static String toPath(Object[] entries) {
+		if ((null == entries) || (0 == entries.length)) {
+			return "";
+		}
+		StringBuffer path = new StringBuffer();
+		boolean started = false;
+		for (int i = 0; i < entries.length; i++) {
+			if (null != entries[i]) {
+				if (started) {
+					path.append(File.pathSeparator);
+				} else {
+					started = true;
+				}
+				path.append(entries[i].toString());
+			}
+		}
+		return path.toString();
+	}
+
+	/**
+	 * @param input the String to parse for [on|off|true|false]
+	 * @throws IllegalArgumentException if input is bad
+	 **/
+	public static boolean parseBoolean(String input) {
+		return parseBoolean(input, true);
+	}
+
+	/**
+	 * @param input the String to parse for [on|off|true|false]
+	 * @param iaxOnError if true and input is bad, throw IllegalArgumentException
+	 * @return true if input is true, false otherwise
+	 * @throws IllegalArgumentException if iaxOnError and input is bad
+	 */
+	public static boolean parseBoolean(final String input, boolean iaxOnError) {
+		final String syntax = ": [on|off|true|false]";
+		if (null == input) {
+			return false;
+		}
+		String lc = input.trim().toLowerCase();
+		boolean result = false;
+		boolean valid = false;
+		switch (lc.length()) {
+		case 2:
+			if (valid = "on".equals(lc)) {
+				result = true;
+			}
+			break;
+		case 3:
+			valid = "off".equals(lc);
+			break;
+		case 4:
+			if (valid = "true".equals(lc)) {
+				result = true;
+			}
+			break;
+		case 5:
+			valid = "false".equals(lc);
+			break;
+		}
+		if (iaxOnError && !valid) {
+			throw new IllegalArgumentException(input + syntax);
+		}
+		return result;
+	}
+
+	public static File aspectjrtJarFile() {
+		return (File) LIB_ENTRIES.get(ASPECTJRT_KEY + ".file");
+	}
+
+	public static URL aspectjrtJarURL() {
+		return (URL) LIB_ENTRIES.get(ASPECTJRT_KEY + ".url");
+	}
+
+	public static File testingClientJarFile() {
+		return (File) LIB_ENTRIES.get(TESTING_CLIENT_KEY + ".file");
+	}
+
+	public static URL testingClientJarURL() {
+		return (URL) LIB_ENTRIES.get(TESTING_CLIENT_KEY + ".url");
+	}
+
+	/**
+	 * 
+	 * @param rpath the String relative path from the library directory to a resource that must exist (may be a directory), using
+	 *        forward slashes as a file separator
+	 * @return the File path
+	 * @throws IllegalArgumentException if no such directory or file
+	 */
+	public static File libFile(String rpath) {
+		if ((null == rpath) || (0 == rpath.length())) {
+			throw new IllegalArgumentException("no input");
+		}
+		rpath = rpath.replace('/', File.separatorChar);
+		File result = new File(LIB_DIR, rpath);
+		if (result.exists()) {
+			return result;
+		}
+		throw new IllegalArgumentException("not in " + LIB_DIR + ": " + rpath);
+	}
+
+	/**
+	 * Like libPath, only it returns a URL.
+	 * 
+	 * @return URL or null if it does not exist
+	 * @throws IllegalArgumentException if no such directory or file
+	 */
+	public static URL libURL(String rpath) {
+		File file = libFile(rpath);
+		try {
+			return file.toURL();
+		} catch (MalformedURLException e) {
+			throw new IllegalArgumentException("bad URL from: " + file);
+		}
+	}
+
+	// ---- arrays
+
+	public static void assertArrayEquals(String msg, Object[] expected, Object[] found) {
+		TestCase.assertEquals(msg, Arrays.asList(expected), Arrays.asList(found));
+	}
+
+	// ---- unordered
+
+	public static void assertSetEquals(Collection expected, Collection found) {
+		assertSetEquals(null, expected, found);
+	}
+
+	public static void assertSetEquals(String msg, Object[] expected, Object[] found) {
+		assertSetEquals(msg, Arrays.asList(expected), Arrays.asList(found));
+	}
+
+	public static void assertSetEquals(String msg, Collection expected, Collection found) {
+		msg = (msg == null) ? "" : msg + ": ";
+
+		Set results1 = new HashSet(found);
+		results1.removeAll(expected);
+
+		Set results2 = new HashSet(expected);
+		results2.removeAll(found);
+
+		if (results1.isEmpty()) {
+			TestCase.assertTrue(msg + "Expected but didn't find: " + results2.toString(), results2.isEmpty());
+		} else if (results2.isEmpty()) {
+			TestCase.assertTrue(msg + "Didn't expect: " + results1.toString(), results1.isEmpty());
+		} else {
+			TestCase.assertTrue(msg + "Expected but didn't find: " + results2.toString() + "\nDidn't expect: "
+					+ results1.toString(), false);
+		}
+	}
+
+	// ---- objects
+
+	public static void assertCommutativeEquals(Object a, Object b, boolean should) {
+		TestCase.assertEquals(a + " equals " + b, should, a.equals(b));
+		TestCase.assertEquals(b + " equals " + a, should, b.equals(a));
+		assertHashEquals(a, b, should);
+	}
+
+	private static void assertHashEquals(Object s, Object t, boolean should) {
+		if (should) {
+			TestCase.assertTrue(s + " does not hash to same as " + t, s.hashCode() == t.hashCode());
+		} else {
+			if (s.hashCode() == t.hashCode()) {
+				System.err.println("warning: hash collision with hash = " + t.hashCode());
+				System.err.println("  for " + s);
+				System.err.println("  and " + t);
+			}
+		}
+	}
+
+	// -- reflective stuff
+
+	public static void runMain(String classPath, String className) {
+		runMethod(classPath, className, "main", new Object[] { new String[0] });
+	}
+
+	public static Object runMethod(String classPath, String className, String methodName, Object[] args) {
+		classPath += File.pathSeparator + System.getProperty("java.class.path");
+
+		ClassLoader loader = new TestCaseClassLoader(classPath);
+
+		Class c = null;
+		try {
+			c = loader.loadClass(className);
+		} catch (ClassNotFoundException e) {
+			Assert.assertTrue("unexpected exception: " + e, false);
+		}
+		return Reflection.invokestaticN(c, methodName, args);
+	}
+
+	/**
+	 * Checks that two multi-line strings have the same value. Each line is trimmed before comparision Produces an error on the
+	 * particular line of conflict
+	 */
+	public static void assertMultiLineStringEquals(String message, String s1, String s2) {
+		try {
+			BufferedReader r1 = new BufferedReader(new StringReader(s1));
+			BufferedReader r2 = new BufferedReader(new StringReader(s2));
+
+			List lines = new ArrayList();
+			String l1, l2;
+
+			int index = 1;
+			while (true) {
+				l1 = readNonBlankLine(r1);
+				l2 = readNonBlankLine(r2);
+				if (l1 == null || l2 == null)
+					break;
+				if (l1.equals(l2)) {
+					lines.add(l1);
+				} else {
+					showContext(lines);
+					Assert.assertEquals(message + "(line " + index + "):\n" + l1 + "\n" + l2, l1, l2);
+				}
+				index++;
+			}
+			if (l1 != null)
+				showContext(lines);
+			Assert.assertTrue(message + ": unexpected " + l1, l1 == null);
+			if (l2 != null)
+				showContext(lines);
+			Assert.assertTrue(message + ": unexpected " + l2, l2 == null);
+		} catch (IOException ioe) {
+			Assert.assertTrue(message + ": caught " + ioe.getMessage(), false);
+		}
+	}
+
+	private static void showContext(List lines) {
+		int n = lines.size();
+		for (int i = Math.max(0, n - 8); i < n; i++) {
+			System.err.println(lines.get(i));
+		}
+	}
+
+	private static String readNonBlankLine(BufferedReader r) throws IOException {
+		String l = r.readLine();
+		if (l == null)
+			return null;
+		l = l.trim();
+		// comment to include comments when reading
+		int commentLoc = l.indexOf("//");
+		if (-1 != commentLoc) {
+			l = l.substring(0, commentLoc).trim();
+		}
+		if ("".equals(l))
+			return readNonBlankLine(r);
+		return l;
+	}
+
+	/**
+	 * If there is an expected dir, expect each file in its subtree to match a corresponding actual file in the base directory. This
+	 * does NOT check that all actual files have corresponding expected files. This ignores directory paths containing "CVS".
+	 * 
+	 * @param handler the IMessageHandler sink for error messages
+	 * @param expectedBaseDir the File path to the directory containing expected files, all of which are compared with any
+	 *        corresponding actual files
+	 * @param actualBaseDir the File path to the base directory from which to find any actual files corresponding to expected files.
+	 * @return true if all files in the expectedBaseDir directory tree have matching files in the actualBaseDir directory tree.
+	 */
+	public static boolean sameDirectoryContents(final IMessageHandler handler, final File expectedBaseDir,
+			final File actualBaseDir, final boolean fastFail) {
+		LangUtil.throwIaxIfNull(handler, "handler");
+		if (!FileUtil.canReadDir(expectedBaseDir)) {
+			MessageUtil.fail(handler, " expected dir not found: " + expectedBaseDir);
+			return false;
+		}
+		if (!FileUtil.canReadDir(actualBaseDir)) {
+			MessageUtil.fail(handler, " actual dir not found: " + actualBaseDir);
+			return false;
+		}
+		String[] paths = FileUtil.listFiles(expectedBaseDir);
+		boolean result = true;
+		for (int i = 0; i < paths.length; i++) {
+			if (-1 != paths[i].indexOf("CVS")) {
+				continue;
+			}
+			if (!sameFiles(handler, expectedBaseDir, actualBaseDir, paths[i]) && result) {
+				result = false;
+				if (fastFail) {
+					break;
+				}
+			}
+		}
+		return result;
+	}
+
+	// ------------ File-comparison utilities (XXX need their own class...)
+	/**
+	 * Test interface to compare two files, line by line, and report differences as one FAIL message if a handler is supplied. This
+	 * preprocesses .class files by disassembling.
+	 * 
+	 * @param handler the IMessageHandler for any FAIL messages (null to ignore)
+	 * @param expectedFile the File path to the canonical file
+	 * @param actualFile the File path to the actual file, if any
+	 * @return true if the input files are the same, based on per-line comparisons
+	 */
+	public static boolean sameFiles(IMessageHandler handler, File expectedFile, File actualFile) {
+		return doSameFile(handler, null, null, expectedFile, actualFile);
+	}
+
+	/**
+	 * Test interface to compare two files, line by line, and report differences as one FAIL message if a handler is supplied. This
+	 * preprocesses .class files by disassembling. This method assumes that the files are at the same offset from two respective
+	 * base directories.
+	 * 
+	 * @param handler the IMessageHandler for any FAIL messages (null to ignore)
+	 * @param expectedBaseDir the File path to the canonical file base directory
+	 * @param actualBaseDir the File path to the actual file base directory
+	 * @param path the String path offset from the base directories
+	 * @return true if the input files are the same, based on per-line comparisons
+	 */
+	public static boolean sameFiles(IMessageHandler handler, File expectedBaseDir, File actualBaseDir, String path) {
+		File actualFile = new File(actualBaseDir, path);
+		File expectedFile = new File(expectedBaseDir, path);
+		return doSameFile(handler, expectedBaseDir, actualBaseDir, expectedFile, actualFile);
+	}
+
+	/**
+	 * This does the work, selecting a lineator subclass and converting public API's to JDiff APIs for comparison. Currently, all
+	 * jdiff interfaces are method-local, so this class will load without it; if we do use it, we can avoid the duplication.
+	 */
+	private static boolean doSameFile(IMessageHandler handler, File expectedBaseDir, File actualBaseDir, File expectedFile,
+			File actualFile) {
+		String path = expectedFile.getPath();
+		// XXX permit user to specify lineator
+		ILineator lineator = Lineator.TEXT;
+		if (path.endsWith(".class")) {
+			if (ClassLineator.haveDisassembler()) {
+				lineator = Lineator.CLASS;
+			} else {
+				MessageUtil.abort(handler, "skipping - dissassembler not available");
+				return false;
+			}
+		}
+		CanonicalLine[] actualLines = null;
+		CanonicalLine[] expectedLines = null;
+		try {
+			actualLines = lineator.getLines(handler, actualFile, actualBaseDir);
+			expectedLines = lineator.getLines(handler, expectedFile, expectedBaseDir);
+		} catch (IOException e) {
+			MessageUtil.fail(handler, "rendering lines ", e);
+			return false;
+		}
+		if (!LangUtil.isEmpty(actualLines) && !LangUtil.isEmpty(expectedLines)) {
+			// here's the transmutation back to jdiff - extract if publishing
+			// JDiff
+			CanonicalLine[][] clines = new CanonicalLine[][] { expectedLines, actualLines };
+			FileLine[][] flines = new FileLine[2][];
+			for (int i = 0; i < clines.length; i++) {
+				CanonicalLine[] cline = clines[i];
+				FileLine[] fline = new FileLine[cline.length];
+				for (int j = 0; j < fline.length; j++) {
+					fline[j] = new FileLine(cline[j].canonical, cline[j].line);
+				}
+				flines[i] = fline;
+			}
+
+			Diff.change edits = new Diff(flines[0], flines[1]).diff_2(false);
+			if ((null == edits) || (0 == (edits.inserted + edits.deleted))) {
+				// XXX confirm with jdiff that null means no edits
+				return true;
+			} else {
+				// String m = render(handler, edits, flines[0], flines[1]);
+				StringWriter writer = new StringWriter();
+				DiffNormalOutput out = new DiffNormalOutput(flines[0], flines[1]);
+				out.setOut(writer);
+				out.setLineSeparator(LangUtil.EOL);
+				try {
+					out.writeScript(edits);
+				} catch (IOException e) {
+					MessageUtil.fail(handler, "rendering edits", e);
+				} finally {
+					if (null != writer) {
+						try {
+							writer.close();
+						} catch (IOException e) {
+							MessageUtil.fail(handler, "closing after rendering edits", e);
+						}
+					}
+				}
+				String message = "diff between " + path + " in expected dir " + expectedBaseDir + " and actual dir "
+						+ actualBaseDir + LangUtil.EOL + writer.toString();
+				MessageUtil.fail(handler, message);
+			}
+		}
+		return false;
+	}
+
+	public static String cleanTestName(String name) {
+		name = name.replace(' ', '_');
+		return name;
+	}
+
+	public static Test skipTest(String tests) {
+		// could printStackTrace to give more context if needed...
+		System.err.println("skipping tests " + tests);
+		return testNamed("skipping tests " + tests);
+	}
+
+	public static Test testNamed(String named) {
+		final String name = cleanTestName(named);
+		return new Test() {
+			public int countTestCases() {
+				return 1;
+			}
+
+			public void run(TestResult r) {
+				r.startTest(this);
+				r.endTest(this);
+			}
+
+			public String toString() {
+				return name;
+			}
+		};
+	}
+
+	/**
+	 * @param sink the TestSuite sink to add result to
+	 * @param sourceName the String fully-qualified name of the class with a suite() method to load
+	 */
+	public static void loadTestsReflectively(TestSuite sink, String sourceName, boolean ignoreError) {
+		Throwable thrown = null;
+		try {
+			ClassLoader loader = sink.getClass().getClassLoader();
+			Class sourceClass = loader.loadClass(sourceName);
+			if (!Modifier.isPublic(sourceClass.getModifiers())) {
+				errorSuite(sink, sourceName, "not public class");
+				return;
+			}
+			Method suiteMethod = sourceClass.getMethod("suite", new Class[0]);
+			int mods = suiteMethod.getModifiers();
+			if (!Modifier.isStatic(mods) || !Modifier.isPublic(mods)) {
+				errorSuite(sink, sourceName, "not static method");
+				return;
+			}
+			if (!Modifier.isPublic(mods)) {
+				errorSuite(sink, sourceName, "not public method");
+				return;
+			}
+			if (!Test.class.isAssignableFrom(suiteMethod.getReturnType())) {
+				errorSuite(sink, sourceName, "suite() does not return Test");
+				return;
+			}
+			Object result = suiteMethod.invoke(null, new Object[0]);
+			Test test = (Test) result;
+			if (!(test instanceof TestSuite)) {
+				sink.addTest(test);
+			} else {
+				TestSuite source = (TestSuite) test;
+				Enumeration tests = source.tests();
+				while (tests.hasMoreElements()) {
+					sink.addTest((Test) tests.nextElement());
+				}
+			}
+
+		} catch (ClassNotFoundException e) {
+			thrown = e;
+		} catch (SecurityException e) {
+			thrown = e;
+		} catch (NoSuchMethodException e) {
+			thrown = e;
+		} catch (IllegalArgumentException e) {
+			thrown = e;
+		} catch (IllegalAccessException e) {
+			thrown = e;
+		} catch (InvocationTargetException e) {
+			thrown = e;
+		}
+		if (null != thrown) {
+			if (ignoreError) {
+				System.err.println("Error loading " + sourceName);
+				thrown.printStackTrace(System.err);
+			} else {
+				errorSuite(sink, sourceName, thrown);
+			}
+		}
+	}
+
+	private static void errorSuite(TestSuite sink, String sourceName, Throwable thrown) {
+		sink.addTest(new ErrorTest(sourceName, thrown));
+	}
+
+	private static void errorSuite(TestSuite sink, String sourceName, String err) {
+		String message = "bad " + sourceName + ": " + err;
+		sink.addTest(new ErrorTest(message));
+	}
+
+	/**
+	 * Junit test failure, e.g., to report suite initialization errors at test time.
+	 */
+	public static class ErrorTest implements Test {
+		private final Throwable thrown;
+
+		public ErrorTest(Throwable thrown) {
+			this.thrown = thrown;
+		}
+
+		public ErrorTest(String message) {
+			this.thrown = new Error(message);
+		}
+
+		public ErrorTest(String message, Throwable thrown) {
+			this(new TestError(message, thrown));
+		}
+
+		public int countTestCases() {
+			return 1;
+		}
+
+		public void run(TestResult result) {
+			result.startTest(this);
+			result.addError(this, thrown);
+		}
+	}
+
+	/**
+	 * Nested exception - remove when using 1.4 or later.
+	 */
+	public static class TestError extends Error {
+		private Throwable thrown;
+
+		public TestError(String message) {
+			super(message);
+		}
+
+		public TestError(String message, Throwable thrown) {
+			super(message);
+			this.thrown = thrown;
+		}
+
+		public Throwable getCause() {
+			return thrown;
+		}
+
+		public void printStackTrace() {
+			printStackTrace(System.err);
+		}
+
+		public void printStackTrace(PrintStream ps) {
+			printStackTrace(new PrintWriter(ps));
+		}
+
+		public void printStackTrace(PrintWriter pw) {
+			super.printStackTrace(pw);
+			if (null != thrown) {
+				pw.print("Caused by: ");
+				thrown.printStackTrace(pw);
+			}
+		}
+	}
+
+	/** component that reduces file to CanonicalLine[] */
+	public static interface ILineator {
+		/** Lineator suitable for text files */
+		public static final ILineator TEXT = new TextLineator();
+
+		/** Lineator suitable for class files (disassembles first) */
+		public static final ILineator CLASS = new ClassLineator();
+
+		/**
+		 * Reduce file to CanonicalLine[].
+		 * 
+		 * @param handler the IMessageHandler for errors (may be null)
+		 * @param file the File to render
+		 * @param basedir the File for the base directory (may be null)
+		 * @return CanonicalLine[] of lines - not null, but perhaps empty
+		 */
+		CanonicalLine[] getLines(IMessageHandler handler, File file, File basedir) throws IOException;
+	}
+
+	/** alias for jdiff FileLine to avoid client binding */
+	public static class CanonicalLine {
+		public static final CanonicalLine[] NO_LINES = new CanonicalLine[0];
+
+		/** canonical variant of line for comparison */
+		public final String canonical;
+
+		/** actual line, for logging */
+		public final String line;
+
+		public CanonicalLine(String canonical, String line) {
+			this.canonical = canonical;
+			this.line = line;
+		}
+
+		public String toString() {
+			return line;
+		}
+	}
+
+	private abstract static class Lineator implements ILineator {
+		/**
+		 * Reduce file to CanonicalLine[].
+		 * 
+		 * @param handler the IMessageHandler for errors (may be null)
+		 * @param file the File to render
+		 * @param basedir the File for the base directory (may be null)
+		 */
+		public CanonicalLine[] getLines(IMessageHandler handler, File file, File basedir) throws IOException {
+
+			if (!file.canRead() || !file.isFile()) {
+				MessageUtil.error(handler, "not readable file: " + basedir + " - " + file);
+				return null;
+			}
+			// capture file as FileLine[]
+			InputStream in = null;
+			/* String path = */FileUtil.normalizedPath(file, basedir);
+			LineStream capture = new LineStream();
+			try {
+				lineate(capture, handler, basedir, file);
+			} catch (IOException e) {
+				MessageUtil.fail(handler, "NormalizedCompareFiles IOException reading " + file, e);
+				return null;
+			} finally {
+				if (null != in) {
+					try {
+						in.close();
+					} catch (IOException e) {
+					} // ignore
+				}
+				capture.flush();
+				capture.close();
+			}
+			String missed = capture.getMissed();
+			if (!LangUtil.isEmpty(missed)) {
+				MessageUtil.warn(handler, "NormalizedCompareFiles missed input: " + missed);
+				return null;
+			} else {
+				String[] lines = capture.getLines();
+				CanonicalLine[] result = new CanonicalLine[lines.length];
+				for (int i = 0; i < lines.length; i++) {
+					result[i] = new CanonicalLine(lines[i], lines[i]);
+				}
+				return result;
+			}
+		}
+
+		protected abstract void lineate(PrintStream sink, IMessageHandler handler, File basedir, File file) throws IOException;
+	}
+
+	private static class TextLineator extends Lineator {
+
+		protected void lineate(PrintStream sink, IMessageHandler handler, File basedir, File file) throws IOException {
+			InputStream in = null;
+			try {
+				in = new FileInputStream(file);
+				FileUtil.copyStream(new DataInputStream(in), sink);
+			} finally {
+				try {
+					in.close();
+				} catch (IOException e) {
+				} // ignore
+			}
+		}
+	}
+
+	public static class ClassLineator extends Lineator {
+
+		protected void lineate(PrintStream sink, IMessageHandler handler, File basedir, File file) throws IOException {
+			String name = FileUtil.fileToClassName(basedir, file);
+			// XXX re-enable preflight?
+			// if ((null != basedir) && (path.length()-6 != name.length())) {
+			// MessageUtil.error(handler, "unexpected class name \""
+			// + name + "\" for path " + path);
+			// return null;
+			// }
+			disassemble(handler, basedir, name, sink);
+		}
+
+		public static boolean haveDisassembler() {
+			try {
+				return (null != Class.forName("org.aspectj.weaver.bcel.LazyClassGen"));
+			} catch (ClassNotFoundException e) {
+				// XXX fix
+				// System.err.println(e.getMessage());
+				// e.printStackTrace(System.err);
+				return false;
+			}
+		}
+
+		/** XXX dependency on bcweaver/bcel */
+		private static void disassemble(IMessageHandler handler, File basedir, String name, PrintStream out) throws IOException {
+			// LazyClassGen.disassemble(FileUtil.normalizedPath(basedir), name,
+			// capture);
+
+			Throwable thrown = null;
+			String basedirPath = FileUtil.normalizedPath(basedir);
+			// XXX use reflection utilities to invoke dissassembler?
+			try {
+				// XXX need test to detect when this is refactored
+				Class c = Class.forName("org.aspectj.weaver.bcel.LazyClassGen");
+				Method m = c.getMethod("disassemble", new Class[] { String.class, String.class, PrintStream.class });
+				m.invoke(null, new Object[] { basedirPath, name, out });
+			} catch (ClassNotFoundException e) {
+				thrown = e;
+			} catch (NoSuchMethodException e) {
+				thrown = e;
+			} catch (IllegalAccessException e) {
+				thrown = e;
+			} catch (InvocationTargetException e) {
+				Throwable t = e.getTargetException();
+				if (t instanceof IOException) {
+					throw (IOException) t;
+				}
+				thrown = t;
+			}
+			if (null != thrown) {
+				MessageUtil.fail(handler, "disassembling " + name + " path: " + basedirPath, thrown);
+			}
+		}
+	}
+
+	/**
+	 * Capture PrintStream output to String[] (delimiting component String on println()), also showing any missed text.
+	 */
+	public static class LineStream extends PrintStream {
+		StringBuffer sb = new StringBuffer();
+
+		ByteArrayOutputStream missed;
+
+		ArrayList sink;
+
+		public LineStream() {
+			super(new ByteArrayOutputStream());
+			this.sink = new ArrayList();
+			missed = (ByteArrayOutputStream) out;
+		}
+
+		/** @return any text not captured by our overrides */
+		public String getMissed() {
+			return missed.toString();
+		}
+
+		/** clear captured lines (but not missed text) */
+		public void clear() {
+			sink.clear();
+		}
+
+		/**
+		 * Get String[] of lines printed, delimited by println(..) calls.
+		 * 
+		 * @return lines printed, exclusive of any not yet terminated by newline
+		 */
+		public String[] getLines() {
+			return (String[]) sink.toArray(new String[0]);
+		}
+
+		// ---------- PrintStream overrides
+		public void println(Object x) {
+			println(x.toString());
+		}
+
+		public void print(Object obj) {
+			print(obj.toString());
+		}
+
+		public void println(char c) {
+			sb.append(c);
+			println();
+		}
+
+		public void println(char[] c) {
+			sb.append(c);
+			println();
+		}
+
+		public void print(char c) {
+			sb.append(c);
+		}
+
+		public void print(char[] c) {
+			sb.append(c);
+		}
+
+		public void println(String s) {
+			print(s);
+			println();
+		}
+
+		public void print(String s) {
+			sb.append(s);
+		}
+
+		public void println() {
+			String line = sb.toString();
+			sink.add(line);
+			sb.setLength(0);
+		}
+	}
+
+}