/*
* SonarQube Java
* Copyright (C) 2012-2016 SonarSource SA
* mailto:contact 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 org.sonar.check.Rule;
import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.LambdaExpressionTree;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.ReturnStatementTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.Tree.Kind;
import java.util.List;
@Rule(key = "S2447")
public class BooleanMethodReturnCheck 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 (!isAnnotatedWithCheckForNull(methodTree) && returnsBoolean(methodTree)) {
methodTree.accept(new ReturnStatementVisitor());
}
}
private static boolean isAnnotatedWithCheckForNull(MethodTree methodTree) {
return methodTree.symbol().metadata().isAnnotatedWith("javax.annotation.CheckForNull");
}
private static boolean returnsBoolean(MethodTree methodTree) {
return methodTree.returnType().symbolType().is("java.lang.Boolean");
}
private class ReturnStatementVisitor extends BaseTreeVisitor {
@Override
public void visitLambdaExpression(LambdaExpressionTree lambdaExpressionTree) {
// skip lambdas
}
@Override
public void visitReturnStatement(ReturnStatementTree tree) {
if (tree.expression().is(Kind.NULL_LITERAL)) {
reportIssue(tree.expression(), "Null is returned but a \"Boolean\" is expected.");
}
}
@Override
public void visitClass(ClassTree tree) {
// Do not visit inner classes as methods of inner classes will be visited by main visitor
}
}
}