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.Set;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.DetailAST;
026import com.puppycrawl.tools.checkstyle.api.DetailNode;
027import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
028import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
029import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
030
031/**
032 * <div>
033 * Checks that a Javadoc block can fit in a single-line and doesn't contain block tags.
034 * Javadoc comment that contains at least one block tag should be formatted in a few lines.
035 * </div>
036 *
037 * <ul>
038 * <li>
039 * Property {@code ignoreInlineTags} - Control whether
040 * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDBEFIF">
041 * inline tags</a> must be ignored.
042 * Type is {@code boolean}.
043 * Default value is {@code true}.
044 * </li>
045 * <li>
046 * Property {@code ignoredTags} - Specify
047 * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDBEFIF">
048 * block tags</a> which are ignored by the check.
049 * Type is {@code java.lang.String[]}.
050 * Default value is {@code ""}.
051 * </li>
052 * <li>
053 * Property {@code violateExecutionOnNonTightHtml} - Control when to print violations
054 * if the Javadoc being examined by this check violates the tight html rules defined at
055 * <a href="https://checkstyle.org/writingjavadocchecks.html#Tight-HTML_rules">Tight-HTML Rules</a>.
056 * Type is {@code boolean}.
057 * Default value is {@code false}.
058 * </li>
059 * </ul>
060 *
061 * <p>
062 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
063 * </p>
064 *
065 * <p>
066 * Violation Message Keys:
067 * </p>
068 * <ul>
069 * <li>
070 * {@code javadoc.missed.html.close}
071 * </li>
072 * <li>
073 * {@code javadoc.parse.rule.error}
074 * </li>
075 * <li>
076 * {@code javadoc.unclosedHtml}
077 * </li>
078 * <li>
079 * {@code javadoc.wrong.singleton.html.tag}
080 * </li>
081 * <li>
082 * {@code singleline.javadoc}
083 * </li>
084 * </ul>
085 *
086 * @since 6.0
087 */
088@StatelessCheck
089public class SingleLineJavadocCheck extends AbstractJavadocCheck {
090
091    /**
092     * A key is pointing to the warning message text in "messages.properties"
093     * file.
094     */
095    public static final String MSG_KEY = "singleline.javadoc";
096
097    /**
098     * Specify
099     * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDBEFIF">
100     * block tags</a> which are ignored by the check.
101     */
102    private Set<String> ignoredTags = Set.of();
103
104    /**
105     * Control whether
106     * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDBEFIF">
107     * inline tags</a> must be ignored.
108     */
109    private boolean ignoreInlineTags = true;
110
111    /**
112     * Setter to specify
113     * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDBEFIF">
114     * block tags</a> which are ignored by the check.
115     *
116     * @param tags to be ignored by check.
117     * @since 6.8
118     */
119    public void setIgnoredTags(String... tags) {
120        ignoredTags = Set.of(tags);
121    }
122
123    /**
124     * Setter to control whether
125     * <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDBEFIF">
126     * inline tags</a> must be ignored.
127     *
128     * @param ignoreInlineTags whether inline tags must be ignored.
129     * @since 6.8
130     */
131    public void setIgnoreInlineTags(boolean ignoreInlineTags) {
132        this.ignoreInlineTags = ignoreInlineTags;
133    }
134
135    @Override
136    public int[] getDefaultJavadocTokens() {
137        return new int[] {
138            JavadocTokenTypes.JAVADOC,
139        };
140    }
141
142    @Override
143    public int[] getRequiredJavadocTokens() {
144        return getAcceptableJavadocTokens();
145    }
146
147    @Override
148    public void visitJavadocToken(DetailNode ast) {
149        if (isSingleLineJavadoc(getBlockCommentAst())
150                && (hasJavadocTags(ast) || !ignoreInlineTags && hasJavadocInlineTags(ast))) {
151            log(ast.getLineNumber(), MSG_KEY);
152        }
153    }
154
155    /**
156     * Checks if comment is single-line comment.
157     *
158     * @param blockCommentStart the AST tree in which a block comment starts
159     * @return true, if comment is single-line comment.
160     */
161    private static boolean isSingleLineJavadoc(DetailAST blockCommentStart) {
162        final DetailAST blockCommentEnd = blockCommentStart.getLastChild();
163        return TokenUtil.areOnSameLine(blockCommentStart, blockCommentEnd);
164    }
165
166    /**
167     * Checks if comment has javadoc tags which are not ignored. Also works
168     * on custom tags. As block tags can be interpreted only at the beginning of a line,
169     * only the first instance is checked.
170     *
171     * @param javadocRoot javadoc root node.
172     * @return true, if comment has javadoc tags which are not ignored.
173     * @see <a href=
174     * "https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#blockandinlinetags">
175     * Block and inline tags</a>
176     */
177    private boolean hasJavadocTags(DetailNode javadocRoot) {
178        final DetailNode javadocTagSection =
179                JavadocUtil.findFirstToken(javadocRoot, JavadocTokenTypes.JAVADOC_TAG);
180        return javadocTagSection != null && !isTagIgnored(javadocTagSection);
181    }
182
183    /**
184     * Checks if comment has in-line tags which are not ignored.
185     *
186     * @param javadocRoot javadoc root node.
187     * @return true, if comment has in-line tags which are not ignored.
188     * @see <a href=
189     * "https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#javadoctags">
190     * JavadocTags</a>
191     */
192    private boolean hasJavadocInlineTags(DetailNode javadocRoot) {
193        DetailNode javadocTagSection =
194                JavadocUtil.findFirstToken(javadocRoot, JavadocTokenTypes.JAVADOC_INLINE_TAG);
195        boolean foundTag = false;
196        while (javadocTagSection != null) {
197            if (!isTagIgnored(javadocTagSection)) {
198                foundTag = true;
199                break;
200            }
201            javadocTagSection = JavadocUtil.getNextSibling(
202                    javadocTagSection, JavadocTokenTypes.JAVADOC_INLINE_TAG);
203        }
204        return foundTag;
205    }
206
207    /**
208     * Checks if list of ignored tags contains javadocTagSection's javadoc tag.
209     *
210     * @param javadocTagSection to check javadoc tag in.
211     * @return true, if ignoredTags contains javadocTagSection's javadoc tag.
212     */
213    private boolean isTagIgnored(DetailNode javadocTagSection) {
214        return ignoredTags.contains(JavadocUtil.getTagName(javadocTagSection));
215    }
216
217}