org.sonar.java.checks.TrailingCommentCheck.java Source code

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Here is the source code for org.sonar.java.checks.TrailingCommentCheck.java

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/*
 * SonarQube Java
 * Copyright (C) 2012-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.java.checks;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import org.apache.commons.lang.StringUtils;
import org.sonar.check.Rule;
import org.sonar.check.RuleProperty;
import org.sonar.java.RspecKey;
import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.tree.SyntaxToken;
import org.sonar.plugins.java.api.tree.SyntaxTrivia;
import org.sonar.plugins.java.api.tree.Tree;

import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;

@Rule(key = "TrailingCommentCheck")
@RspecKey("S139")
public class TrailingCommentCheck extends IssuableSubscriptionVisitor {

    private static final String DEFAULT_LEGAL_COMMENT_PATTERN = "^\\s*+[^\\s]++$";
    private static final Set<String> EXCLUDED_PATTERNS = ImmutableSet.of("NOSONAR", "NOPMD", "CHECKSTYLE:");

    @RuleProperty(key = "legalTrailingCommentPattern", description = "Description Pattern for text of trailing comments that are allowed. By default, comments containing only one word.", defaultValue = DEFAULT_LEGAL_COMMENT_PATTERN)
    public String legalCommentPattern = DEFAULT_LEGAL_COMMENT_PATTERN;

    private Pattern pattern;
    private boolean ignoreMultipleOccurences;
    private Set<SyntaxToken> visitedTokens;
    private int previousTokenLine;

    @Override
    public List<Tree.Kind> nodesToVisit() {
        return ImmutableList.of(Tree.Kind.TOKEN, Tree.Kind.VARIABLE);
    }

    @Override
    public void scanFile(JavaFileScannerContext context) {
        previousTokenLine = -1;
        pattern = Pattern.compile(legalCommentPattern);
        visitedTokens = Sets.newHashSet();
        super.scanFile(context);
        visitedTokens.clear();
    }

    @Override
    public void visitNode(Tree tree) {
        ignoreMultipleOccurences = true;
    }

    @Override
    public void leaveNode(Tree tree) {
        ignoreMultipleOccurences = false;
    }

    @Override
    public void visitToken(SyntaxToken syntaxToken) {
        if (ignoreMultipleOccurences && !visitedTokens.add(syntaxToken)) {
            return;
        }
        int tokenLine = syntaxToken.line();
        if (tokenLine != previousTokenLine) {
            syntaxToken.trivias().stream().filter(trivia -> trivia.startLine() == previousTokenLine)
                    .map(SyntaxTrivia::comment)
                    .map(comment -> comment.startsWith("//") ? comment.substring(2)
                            : comment.substring(2, comment.length() - 2))
                    .map(String::trim)
                    .filter(comment -> !pattern.matcher(comment).matches() && !containsExcludedPattern(comment))
                    .forEach(comment -> addIssue(previousTokenLine,
                            "Move this trailing comment on the previous empty line."));
        }

        previousTokenLine = tokenLine;
    }

    private static boolean containsExcludedPattern(String comment) {
        for (String excludePattern : EXCLUDED_PATTERNS) {
            if (StringUtils.containsIgnoreCase(comment, excludePattern)) {
                return true;
            }
        }
        return false;
    }
}