001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks;
021
022import java.util.regex.Pattern;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.TokenTypes;
028
029/**
030 * <div>
031 * Checks for {@code TODO:} comments. Actually it is a generic
032 * <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/regex/Pattern.html">
033 * pattern</a> matcher on Java comments. To check for other patterns
034 * in Java comments, set the {@code format} property.
035 * </div>
036 *
037 * <p>
038 * Notes:
039 * Using {@code TODO:} comments is a great way to keep track of tasks that need to be done.
040 * Having them reported by Checkstyle makes it very hard to forget about them.
041 * </p>
042 *
043 * @since 3.0
044 */
045@StatelessCheck
046public class TodoCommentCheck
047        extends AbstractCheck {
048
049    /**
050     * A key is pointing to the warning message text in "messages.properties"
051     * file.
052     */
053    public static final String MSG_KEY = "todo.match";
054
055    /**
056     * Specify pattern to match comments against.
057     */
058    private Pattern format = Pattern.compile("TODO:");
059
060    /**
061     * Creates a new {@code TodoCommentCheck} instance.
062     */
063    public TodoCommentCheck() {
064        // no code by default
065    }
066
067    @Override
068    public boolean isCommentNodesRequired() {
069        return true;
070    }
071
072    /**
073     * Setter to specify pattern to match comments against.
074     *
075     * @param pattern
076     *        pattern of 'todo' comment.
077     * @since 3.0
078     */
079    public void setFormat(Pattern pattern) {
080        format = pattern;
081    }
082
083    @Override
084    public int[] getDefaultTokens() {
085        return getRequiredTokens();
086    }
087
088    @Override
089    public int[] getAcceptableTokens() {
090        return getRequiredTokens();
091    }
092
093    @Override
094    public int[] getRequiredTokens() {
095        return new int[] {TokenTypes.COMMENT_CONTENT };
096    }
097
098    @Override
099    public void visitToken(DetailAST ast) {
100        final String[] lines = ast.getText().split("\n", -1);
101
102        for (String line : lines) {
103            if (format.matcher(line).find()) {
104                log(ast, MSG_KEY, format.pattern());
105            }
106        }
107    }
108
109}