org.sonar.java.checks.SelectorMethodArgumentCheck.java Source code

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Here is the source code for org.sonar.java.checks.SelectorMethodArgumentCheck.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.Iterables;
import com.google.common.collect.Lists;
import org.sonar.check.Rule;
import org.sonar.java.model.ModifiersUtils;
import org.sonar.java.model.declaration.MethodTreeImpl;
import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
import org.sonar.plugins.java.api.semantic.Symbol;
import org.sonar.plugins.java.api.semantic.Type;
import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
import org.sonar.plugins.java.api.tree.BlockTree;
import org.sonar.plugins.java.api.tree.ConditionalExpressionTree;
import org.sonar.plugins.java.api.tree.ExpressionTree;
import org.sonar.plugins.java.api.tree.IdentifierTree;
import org.sonar.plugins.java.api.tree.IfStatementTree;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.Modifier;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.Tree.Kind;
import org.sonar.plugins.java.api.tree.VariableTree;

import java.text.MessageFormat;
import java.util.Collection;
import java.util.List;

@Rule(key = "S2301")
public class SelectorMethodArgumentCheck extends IssuableSubscriptionVisitor {

    @Override
    public List<Kind> nodesToVisit() {
        return ImmutableList.of(Kind.METHOD);
    }

    @Override
    public void visitNode(Tree tree) {
        if (!hasSemantic()) {
            return;
        }
        MethodTree methodTree = (MethodTree) tree;
        if (Boolean.TRUE.equals(((MethodTreeImpl) methodTree).isOverriding())) {
            return;
        }
        List<Symbol> booleanParameterSymbols = getBooleanParametersAsSymbol(methodTree.parameters());
        BlockTree blockTree = methodTree.block();

        if (isPublic(methodTree) && blockTree != null && !booleanParameterSymbols.isEmpty()) {
            for (Symbol variable : booleanParameterSymbols) {
                Collection<IdentifierTree> usages = variable.usages();
                if (usages.size() == 1) {
                    blockTree.accept(
                            new ConditionalStatementVisitor(variable.name(), Iterables.get(usages, 0), methodTree));
                }
            }
        }
    }

    private static boolean isPublic(MethodTree methodTree) {
        return ModifiersUtils.hasModifier(methodTree.modifiers(), Modifier.PUBLIC);
    }

    private static List<Symbol> getBooleanParametersAsSymbol(List<VariableTree> parameters) {
        List<Symbol> booleanParameters = Lists.newLinkedList();
        for (VariableTree variableTree : parameters) {
            if (isBooleanVariable(variableTree)) {
                booleanParameters.add(variableTree.symbol());
            }
        }
        return booleanParameters;
    }

    private static boolean isBooleanVariable(VariableTree variableTree) {
        return variableTree.type().symbolType().isPrimitive(Type.Primitives.BOOLEAN);
    }

    private class ConditionalStatementVisitor extends BaseTreeVisitor {

        private final String variableName;
        private final MethodTree method;
        private IdentifierTree usage;

        public ConditionalStatementVisitor(String variableName, IdentifierTree usage, MethodTree method) {
            this.variableName = variableName;
            this.usage = usage;
            this.method = method;
        }

        @Override
        public void visitIfStatement(IfStatementTree tree) {
            checkParameterUsage(tree.condition());
        }

        @Override
        public void visitConditionalExpression(ConditionalExpressionTree tree) {
            checkParameterUsage(tree.condition());
        }

        private void checkParameterUsage(ExpressionTree condition) {
            if (usage.equals(condition)) {
                reportIssue(method.simpleName(), MessageFormat.format(
                        "Provide multiple methods instead of using \"{0}\" to determine which action to take.",
                        variableName));
            }
        }
    }
}