001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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 com.puppycrawl.tools.checkstyle.StatelessCheck;
023import com.puppycrawl.tools.checkstyle.api.DetailNode;
024import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
025import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
026
027/**
028 * <p>
029 * Checks that the at-clause tag is followed by description.
030 * </p>
031 * <ul>
032 * <li>
033 * Property {@code violateExecutionOnNonTightHtml} - Control when to print violations
034 * if the Javadoc being examined by this check violates the tight html rules defined at
035 * <a href="https://checkstyle.org/writingjavadocchecks.html#Tight-HTML_rules">Tight-HTML Rules</a>.
036 * Type is {@code boolean}.
037 * Default value is {@code false}.
038 * </li>
039 * <li>
040 * Property {@code javadocTokens} - javadoc tokens to check
041 * Type is {@code int[]}.
042 * Default value is
043 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/JavadocTokenTypes.html#PARAM_LITERAL">
044 * PARAM_LITERAL</a>,
045 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/JavadocTokenTypes.html#RETURN_LITERAL">
046 * RETURN_LITERAL</a>,
047 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/JavadocTokenTypes.html#THROWS_LITERAL">
048 * THROWS_LITERAL</a>,
049 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/JavadocTokenTypes.html#EXCEPTION_LITERAL">
050 * EXCEPTION_LITERAL</a>,
051 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/JavadocTokenTypes.html#DEPRECATED_LITERAL">
052 * DEPRECATED_LITERAL</a>.
053 * </li>
054 * </ul>
055 * <p>
056 * Default configuration that will check {@code @param}, {@code @return},
057 * {@code @throws}, {@code @deprecated}:
058 * </p>
059 * <pre>
060 * &lt;module name="NonEmptyAtclauseDescription"/&gt;
061 * </pre>
062 * <p>
063 * To configure the check to validate only {@code @param} and {@code @return} tags:
064 * </p>
065 * <pre>
066 * &lt;module name="NonEmptyAtclauseDescription"&gt;
067 *   &lt;property name="javadocTokens" value="PARAM_LITERAL,RETURN_LITERAL"/&gt;
068 * &lt;/module&gt;
069 * </pre>
070 * <p>
071 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
072 * </p>
073 * <p>
074 * Violation Message Keys:
075 * </p>
076 * <ul>
077 * <li>
078 * {@code javadoc.missed.html.close}
079 * </li>
080 * <li>
081 * {@code javadoc.parse.rule.error}
082 * </li>
083 * <li>
084 * {@code javadoc.wrong.singleton.html.tag}
085 * </li>
086 * <li>
087 * {@code non.empty.atclause}
088 * </li>
089 * </ul>
090 *
091 * @since 6.0
092 */
093@StatelessCheck
094public class NonEmptyAtclauseDescriptionCheck extends AbstractJavadocCheck {
095
096    /**
097     * A key is pointing to the warning message text in "messages.properties"
098     * file.
099     */
100    public static final String MSG_KEY = "non.empty.atclause";
101
102    @Override
103    public int[] getDefaultJavadocTokens() {
104        return new int[] {
105            JavadocTokenTypes.PARAM_LITERAL,
106            JavadocTokenTypes.RETURN_LITERAL,
107            JavadocTokenTypes.THROWS_LITERAL,
108            JavadocTokenTypes.EXCEPTION_LITERAL,
109            JavadocTokenTypes.DEPRECATED_LITERAL,
110        };
111    }
112
113    @Override
114    public void visitJavadocToken(DetailNode ast) {
115        if (isEmptyTag(ast.getParent())) {
116            log(ast.getLineNumber(), MSG_KEY, ast.getText());
117        }
118    }
119
120    /**
121     * Tests if at-clause tag is empty.
122     *
123     * @param tagNode at-clause tag.
124     * @return true, if at-clause tag is empty.
125     */
126    private static boolean isEmptyTag(DetailNode tagNode) {
127        final DetailNode tagDescription =
128                JavadocUtil.findFirstToken(tagNode, JavadocTokenTypes.DESCRIPTION);
129        return tagDescription == null;
130    }
131
132}