001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2022 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.io.File;
023import java.util.regex.Pattern;
024
025import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
026import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
027import com.puppycrawl.tools.checkstyle.api.DetailAST;
028import com.puppycrawl.tools.checkstyle.api.TokenTypes;
029import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
030
031/**
032 * <p>
033 * Checks that the outer type name and the file name match.
034 * For example, the class {@code Foo} must be in a file named {@code Foo.java}.
035 * </p>
036 * <p>
037 * To configure the check:
038 * </p>
039 * <pre>
040 * &lt;module name=&quot;OuterTypeFilename&quot;/&gt;
041 * </pre>
042 * <p>Example of class Test in a file named Test.java</p>
043 * <pre>
044 * public class Test { // OK
045 *
046 * }
047 * </pre>
048 * <p>Example of class Foo in a file named Test.java</p>
049 * <pre>
050 * class Foo { // violation
051 *
052 * }
053 * </pre>
054 * <p>Example of interface Foo in a file named Test.java</p>
055 * <pre>
056 * interface Foo { // violation
057 *
058 * }
059 * </pre>
060 * <p>Example of enum Foo in a file named Test.java</p>
061 * <pre>
062 * enum Foo { // violation
063 *
064 * }
065 * </pre>
066 * <p>Example of record Foo in a file named Test.java</p>
067 * <pre>
068 * record Foo { // violation
069 *
070 * }
071 * </pre>
072 * <p>
073 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
074 * </p>
075 * <p>
076 * Violation Message Keys:
077 * </p>
078 * <ul>
079 * <li>
080 * {@code type.file.mismatch}
081 * </li>
082 * </ul>
083 *
084 * @since 5.3
085 */
086@FileStatefulCheck
087public class OuterTypeFilenameCheck extends AbstractCheck {
088
089    /**
090     * A key is pointing to the warning message text in "messages.properties"
091     * file.
092     */
093    public static final String MSG_KEY = "type.file.mismatch";
094
095    /** Pattern matching any file extension with dot included. */
096    private static final Pattern FILE_EXTENSION_PATTERN = Pattern.compile("\\.[^.]*$");
097
098    /** Indicates whether the first token has been seen in the file. */
099    private boolean seenFirstToken;
100
101    /** Current file name. */
102    private String fileName;
103
104    /** If file has public type. */
105    private boolean hasPublic;
106
107    /** Outer type with mismatched file name. */
108    private DetailAST wrongType;
109
110    @Override
111    public int[] getDefaultTokens() {
112        return getRequiredTokens();
113    }
114
115    @Override
116    public int[] getAcceptableTokens() {
117        return getRequiredTokens();
118    }
119
120    @Override
121    public int[] getRequiredTokens() {
122        return new int[] {
123            TokenTypes.CLASS_DEF,
124            TokenTypes.INTERFACE_DEF,
125            TokenTypes.ENUM_DEF,
126            TokenTypes.ANNOTATION_DEF,
127            TokenTypes.RECORD_DEF,
128        };
129    }
130
131    @Override
132    public void beginTree(DetailAST rootAST) {
133        fileName = getFileName();
134        seenFirstToken = false;
135        hasPublic = false;
136        wrongType = null;
137    }
138
139    @Override
140    public void visitToken(DetailAST ast) {
141        if (seenFirstToken) {
142            final DetailAST modifiers = ast.findFirstToken(TokenTypes.MODIFIERS);
143            if (modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null
144                    && TokenUtil.isRootNode(ast.getParent())) {
145                hasPublic = true;
146            }
147        }
148        else {
149            final String outerTypeName = ast.findFirstToken(TokenTypes.IDENT).getText();
150
151            if (!fileName.equals(outerTypeName)) {
152                wrongType = ast;
153            }
154        }
155        seenFirstToken = true;
156    }
157
158    @Override
159    public void finishTree(DetailAST rootAST) {
160        if (!hasPublic && wrongType != null) {
161            log(wrongType, MSG_KEY);
162        }
163    }
164
165    /**
166     * Get source file name.
167     *
168     * @return source file name.
169     */
170    // suppress deprecation until https://github.com/checkstyle/checkstyle/issues/11166
171    @SuppressWarnings("deprecation")
172    private String getFileName() {
173        String name = getFileContents().getFileName();
174        name = name.substring(name.lastIndexOf(File.separatorChar) + 1);
175        return FILE_EXTENSION_PATTERN.matcher(name).replaceAll("");
176    }
177
178}