001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 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.javadoc;
021
022import java.util.Optional;
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;
028import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
029import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
030
031/**
032 * <p>
033 * Checks for missing package definition Javadoc comments in package-info.java files.
034 * </p>
035 * <p>
036 * Rationale: description and other related documentation for a package can be written up
037 * in the package-info.java file and it gets used in the production of the Javadocs.
038 * See <a
039 * href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#packagecomment"
040 * >link</a> for more info.
041 * </p>
042 * <p>
043 * This check specifically only validates package definitions. It will not validate any methods or
044 * interfaces declared in the package-info.java file.
045 * </p>
046 * <p>
047 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
048 * </p>
049 * <p>
050 * Violation Message Keys:
051 * </p>
052 * <ul>
053 * <li>
054 * {@code package.javadoc.missing}
055 * </li>
056 * </ul>
057 *
058 * @since 8.22
059 */
060@StatelessCheck
061public class MissingJavadocPackageCheck extends AbstractCheck {
062
063    /**
064     * A key is pointing to the warning message text in "messages.properties"
065     * file.
066     */
067    public static final String MSG_PKG_JAVADOC_MISSING = "package.javadoc.missing";
068
069    @Override
070    public int[] getDefaultTokens() {
071        return getRequiredTokens();
072    }
073
074    @Override
075    public int[] getAcceptableTokens() {
076        return getRequiredTokens();
077    }
078
079    @Override
080    public int[] getRequiredTokens() {
081        return new int[] {TokenTypes.PACKAGE_DEF};
082    }
083
084    @Override
085    public boolean isCommentNodesRequired() {
086        return true;
087    }
088
089    @Override
090    public void visitToken(DetailAST ast) {
091        if (CheckUtil.isPackageInfo(getFilePath()) && !hasJavadoc(ast)) {
092            log(ast, MSG_PKG_JAVADOC_MISSING);
093        }
094    }
095
096    /**
097     * Checks that there is javadoc before ast.
098     * Because of <a href="https://github.com/checkstyle/checkstyle/issues/4392">parser bug</a>
099     * parser can place javadoc comment either as previous sibling of package definition
100     * or (if there is annotation between package def and javadoc) inside package definition tree.
101     * So we should look for javadoc in both places.
102     *
103     * @param ast {@link TokenTypes#PACKAGE_DEF} token to check
104     * @return true if there is javadoc, false otherwise
105     */
106    private static boolean hasJavadoc(DetailAST ast) {
107        final boolean hasJavadocBefore = ast.getPreviousSibling() != null
108            && isJavadoc(ast.getPreviousSibling());
109        return hasJavadocBefore || hasJavadocAboveAnnotation(ast);
110    }
111
112    /**
113     * Checks javadoc existence in annotations list.
114     *
115     * @param ast package def
116     * @return true if there is a javadoc, false otherwise
117     */
118    private static boolean hasJavadocAboveAnnotation(DetailAST ast) {
119        final Optional<DetailAST> firstAnnotationChild = Optional.of(ast.getFirstChild())
120            .map(DetailAST::getFirstChild)
121            .map(DetailAST::getFirstChild);
122        boolean result = false;
123        if (firstAnnotationChild.isPresent()) {
124            for (DetailAST child = firstAnnotationChild.orElseThrow(); child != null;
125                 child = child.getNextSibling()) {
126                if (isJavadoc(child)) {
127                    result = true;
128                    break;
129                }
130            }
131        }
132        return result;
133    }
134
135    /**
136     * Checks that ast is a javadoc comment.
137     *
138     * @param ast token to check
139     * @return true if ast is a javadoc comment, false otherwise
140     */
141    private static boolean isJavadoc(DetailAST ast) {
142        return ast.getType() == TokenTypes.BLOCK_COMMENT_BEGIN && JavadocUtil.isJavadocComment(ast);
143    }
144}