org.sonar.flex.checks.DuplicateSwitchCaseImplementationCheck.java Source code

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Here is the source code for org.sonar.flex.checks.DuplicateSwitchCaseImplementationCheck.java

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/*
 * SonarQube Flex Plugin
 * Copyright (C) 2010 SonarSource
 * sonarqube@googlegroups.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  02
 */
package org.sonar.flex.checks;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.sonar.sslr.api.AstNode;
import com.sonar.sslr.api.Token;
import org.sonar.check.Priority;
import org.sonar.check.Rule;
import org.sonar.flex.FlexGrammar;
import org.sonar.squidbridge.checks.SquidCheck;
import org.sonar.sslr.parser.LexerlessGrammar;

import javax.annotation.Nullable;
import java.util.List;
import java.util.Map;

@Rule(key = "S1871", priority = Priority.MAJOR)
public class DuplicateSwitchCaseImplementationCheck extends SquidCheck<LexerlessGrammar> {

    @Override
    public void init() {
        subscribeTo(FlexGrammar.SWITCH_STATEMENT);
    }

    @Override
    public void visitNode(AstNode astNode) {
        Map<AstNode, List<Token>> cases = Maps.newLinkedHashMap();

        for (AstNode caseElement : astNode.getChildren(FlexGrammar.CASE_ELEMENT)) {
            AstNode caseLabel = caseElement.getLastChild(FlexGrammar.CASE_LABEL);
            List<Token> tokens = getCaseImplementationTokens(caseElement);

            if (!tokens.isEmpty()) {
                AstNode duplicatedCase = getDuplicatedCase(cases, tokens);

                if (duplicatedCase != null) {
                    getContext().createLineViolation(this,
                            "Either merge this case with the identical one on line \"{0}\" or change one of the implementations.",
                            caseElement, duplicatedCase.getTokenLine());
                } else {
                    cases.put(caseLabel, tokens);
                }
            }
        }
    }

    private List<Token> getCaseImplementationTokens(AstNode caseElement) {
        List<Token> tokens = Lists.newArrayList();

        for (AstNode directive : caseElement.getChildren(FlexGrammar.DIRECTIVE)) {
            tokens.addAll(directive.getTokens());
        }
        return tokens;
    }

    /**
     * Compares case implementation to previous ones.
     *
     * @return duplicated case condition if there is, null otherwise.
     */
    @Nullable
    private AstNode getDuplicatedCase(Map<AstNode, List<Token>> cases, List<Token> tokens) {
        for (Map.Entry<AstNode, List<Token>> entry : cases.entrySet()) {

            if (areTokenValuesIdentical(entry.getValue(), tokens)) {
                return entry.getKey();
            }
        }
        return null;
    }

    private boolean areTokenValuesIdentical(List<Token> implementation1, List<Token> implementation2) {
        int nbToken = implementation1.size();

        if (implementation2.size() != nbToken) {
            return false;
        }

        for (int i = 0; i < nbToken; i++) {
            if (!implementation1.get(i).getValue().equals(implementation2.get(i).getValue())) {
                return false;
            }
        }

        return true;
    }

}