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