trunk/proposal/sandbox/junit/src/main/org/apache/tools/ant/taskdefs/optional/rjunit/JUnitHelper.java

/*
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 * reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
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 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
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 *
 * This software consists of voluntary contributions made by many
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 * information on the Apache Software Foundation, please see
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package org.apache.tools.ant.taskdefs.optional.rjunit;

import java.io.File;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.URL;

import junit.framework.Test;
import junit.framework.TestSuite;
import junit.framework.TestCase;

import org.apache.tools.ant.types.Path;

/**
 * A set of helpers functions to deal with JUnit.
 *
 */
public final class JUnitHelper {

    private final static String SUITE_METHODNAME = "suite";

    /**
     * This method parse the output of the method <tt>toString()</tt>
     * from the <tt>TestCase</tt> class. The format returned is:
     * <tt>name(classname)</tt>
     * @return the string corresponding to name.
     */
    public static String getTestName(String text){
        int p1 = text.indexOf('(');
        return text.substring(0, p1);
    }

    /**
     * This method parse the output of the method <tt>toString()</tt>
     * from the <tt>TestCase</tt> class. The format returned is:
     * <tt>name(classname)</tt>
     * @return the string corresponding to classname.
     */
    public static String getSuiteName(String text){
        int p1 = text.indexOf('(');
        int p2 = text.indexOf(')', p1);
        return text.substring(p1 + 1, p2);
    }

    /**
     * Returns the Test corresponding to to the given class name
     * @param loader classloader to use when loading the class or
     * <tt>null</tt> for system classloader.
     * @param classname the classname of the test we want to extract.
     * @throws Exception a generic exception
     */
    public static Test getTest(ClassLoader loader, String classname) throws Exception {
        Class clazz = null;
        if (loader == null) {
            clazz = Class.forName(classname);
        } else {
            loader.loadClass(classname);
        }
        return getTest(clazz);
    }


    /**
     * Extract a test from a given class
     * @param clazz the class to extract a test from.
     */
    public static Test getTest(Class clazz) {
        try {
            Object obj = clazz.newInstance();
            if (obj instanceof TestSuite) {
                return (TestSuite) obj;
            }
        } catch (Exception e) {
        }
        try {
            // check if there is a suite method
            Method suiteMethod = clazz.getMethod(SUITE_METHODNAME, new Class[0]);
            return (Test) suiteMethod.invoke(null, new Class[0]);
        } catch (Exception e) {
        }

        // check if it is really a valid testcase
        int modifiers = clazz.getModifiers();
        if ( !Modifier.isPublic(modifiers) ||
                Modifier.isAbstract(modifiers) ||
                !TestCase.class.isAssignableFrom(clazz)) {
            return null;
        }
        // try to extract a test suite automatically
        // this will generate warnings if the class is no suitable Test
        try {
            return new TestSuite(clazz);
        } catch (Exception e) {
        }
        return null;
    }

    /**
     * Search for the given resource and return the directory or archive
     * that contains it.
     *
     * <p>Doesn't work for archives in JDK 1.1 as the URL returned by
     * getResource doesn't contain the name of the archive.</p>
     *
     * @param resource the resource to look for in the JVM classpath.
     * @return the file or directory containing the resource or
     * <tt>null</tt> if it does not know how to handle it.
     */
    public static File getResourceEntry(String resource) {
        URL url = JUnitHelper.class.getResource(resource);
        if (url == null) {
            // can't find the resource...
            return null;
        }
        String u = url.toString();
        if (u.startsWith("jar:file:")) {
            int pling = u.indexOf("!");
            String jarName = u.substring(9, pling);
            return new File((new File(jarName)).getAbsolutePath());
        } else if (u.startsWith("file:")) {
            int tail = u.indexOf(resource);
            String dirName = u.substring(5, tail);
            return new File((new File(dirName)).getAbsolutePath());
        }
        // don't know how to handle it...
        return null;
    }

    /**
     * Add the entry corresponding to a specific resource to the
     * specified path instance. The entry can either be a directory
     * or an archive.
     * @param path the path to add the resource entry to.
     * @param resource the resource to look for.
     * @see #getResourceEntry(String)
     */
    public static void addClasspathEntry(Path path, String resource) {
        File f = getResourceEntry(resource);
        if (f != null) {
            path.createPathElement().setLocation(f);
        }
    }

}