////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 the original author or authors.
//
// This library 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 2.1 of the License, or (at your option) any later version.
//
// This library 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 library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.coding;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
/**
* <p>
* Checks for overly complicated boolean expressions. Currently finds code like
* {@code if (b == true)}, {@code b || true}, {@code !false},
* etc.
* </p>
* <p>
* Rationale: Complex boolean logic makes code hard to understand and maintain.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="SimplifyBooleanExpression"/>
* </pre>
* @author lkuehne
*/
public class SimplifyBooleanExpressionCheck
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "simplify.expression";
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {TokenTypes.LITERAL_TRUE, TokenTypes.LITERAL_FALSE};
}
@Override
public int[] getRequiredTokens() {
return getAcceptableTokens();
}
@Override
public void visitToken(DetailAST ast) {
final DetailAST parent = ast.getParent();
switch (parent.getType()) {
case TokenTypes.NOT_EQUAL:
case TokenTypes.EQUAL:
case TokenTypes.LNOT:
case TokenTypes.LOR:
case TokenTypes.LAND:
log(parent.getLineNo(), parent.getColumnNo(),
MSG_KEY);
break;
default:
break;
}
}
}