BaseCheckTestSupport.java

////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
////////////////////////////////////////////////////////////////////////////////

package com.github.sevntu.checkstyle;

import static java.text.MessageFormat.format;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.URL;
import java.util.List;
import java.util.Locale;
import java.util.Properties;

import org.junit.Assert;

import com.google.common.collect.Lists;
import com.puppycrawl.tools.checkstyle.AuditEventUtFormatter;
import com.puppycrawl.tools.checkstyle.Checker;
import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
import com.puppycrawl.tools.checkstyle.DefaultLogger;
import com.puppycrawl.tools.checkstyle.TreeWalker;
import com.puppycrawl.tools.checkstyle.api.AuditEvent;
import com.puppycrawl.tools.checkstyle.api.Configuration;

public abstract class BaseCheckTestSupport extends Assert {
    private final ByteArrayOutputStream baos = new ByteArrayOutputStream();
    private final PrintStream printStream = new PrintStream(baos);

    public static DefaultConfiguration createCheckConfig(Class<?> clazz) {
        return new DefaultConfiguration(clazz.getName());
    }

    protected void verify(Configuration config, String fileName, String[] expected)
            throws Exception {
        verify(createChecker(config), fileName, fileName, expected);
    }

    protected void verify(Checker checker, String fileName, String[] expected) throws Exception {
        verify(checker, fileName, fileName, expected);
    }

    protected void verify(Checker checker, String processedFilename, String messageFileName,
            String[] aExpected) throws Exception {
        verify(checker, new File[] {new File(processedFilename)}, messageFileName, aExpected);
    }

    protected void verify(Checker checker, File[] processedFiles, String messageFileName,
            String[] expected) throws Exception {
        printStream.flush();
        final List<File> testInputFiles = Lists.newArrayList(processedFiles);
        final int foundErrorsCount = checker.process(testInputFiles);

        // Process each output line
        final ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
        final BufferedReader br = new BufferedReader(new InputStreamReader(bais));

        try {
            for (int i = 0; i < expected.length; i++) {
                final String expectedResult = messageFileName + ":" + expected[i];
                final String actual = br.readLine();
                assertEquals("error message " + i, expectedResult, actual);
            }

            assertEquals("Check generated unexpected warning: " + br.readLine(), expected.length,
                    foundErrorsCount);
            checker.destroy();
        }
        finally {
            br.close();
            bais.close();
        }
    }

    protected Checker createChecker(Configuration checkConfig) throws Exception {
        final Checker checker = new Checker();
        // make sure the tests always run with english error messages
        // so the tests don't fail in supported locales like german
        final Locale locale = Locale.ENGLISH;
        checker.setLocaleCountry(locale.getCountry());
        checker.setLocaleLanguage(locale.getLanguage());
        checker.setModuleClassLoader(Thread.currentThread().getContextClassLoader());

        final DefaultConfiguration defaultConfig = createCheckerConfig(checkConfig);
        checker.configure(defaultConfig);

        checker.addListener(new BriefLogger(printStream));
        return checker;
    }

    protected DefaultConfiguration createCheckerConfig(Configuration config) {
        final DefaultConfiguration result = new DefaultConfiguration("configuration");
        final DefaultConfiguration treeWalkerConfig = createCheckConfig(TreeWalker.class);
        // make sure that the tests always run with this charset
        result.addAttribute("charset", "iso-8859-1");
        result.addChild(treeWalkerConfig);
        treeWalkerConfig.addChild(config);
        return result;
    }

    protected String getPath(String filename) {
        String result = null;
        try {
            final URL resource = getClass().getResource(filename);
            if (resource == null) {
                throw new RuntimeException(String.format("Resource '%s' can NOT be found "
                        + "(does not exist or just not visible for current classloader)",
                        filename));
            }
            else {
                result = new File(resource.getPath()).getCanonicalPath();
            }
        }
        catch (IOException ex) {
            throw new RuntimeException("Error while getting path for resource: " + filename, ex);
        }
        return result;
    }

    /**
     * Gets the check message 'as is' from appropriate 'messages.properties' file.
     * @param messageKey the key of message in 'messages.properties' file.
     */
    public String getCheckMessage(String messageKey) {
        final Properties pr = new Properties();
        try {
            pr.load(getClass().getResourceAsStream("messages.properties"));
        }
        catch (IOException ex) {
            return null;
        }
        return pr.getProperty(messageKey);
    }

    /**
     * Gets the check message 'as is' from appropriate 'messages.properties' file.
     * @param messageKey the key of message in 'messages.properties' file.
     * @param arguments the arguments of message in 'messages.properties' file.
     */
    public String getCheckMessage(String messageKey, Object... arguments) {
        return format(getCheckMessage(messageKey), arguments);
    }

    /** A brief logger that only display errors */
    protected static class BriefLogger extends DefaultLogger {

        public BriefLogger(OutputStream out) {
            super(out, true, out, false, new AuditEventUtFormatter());
        }

        @Override
        public void auditStarted(AuditEvent evt) {
        }

        @Override
        public void fileFinished(AuditEvent evt) {
        }

        @Override
        public void fileStarted(AuditEvent evt) {
        }
    }
}