Coverage Report - com.puppycrawl.tools.checkstyle.checks.coding.MultipleVariableDeclarationsCheck
 
Classes in this File Line Coverage Branch Coverage Complexity
MultipleVariableDeclarationsCheck
100%
32/32
100%
26/26
3.4
 
 1  
 ////////////////////////////////////////////////////////////////////////////////
 2  
 // checkstyle: Checks Java source code for adherence to a set of rules.
 3  
 // Copyright (C) 2001-2017 the original author or authors.
 4  
 //
 5  
 // This library is free software; you can redistribute it and/or
 6  
 // modify it under the terms of the GNU Lesser General Public
 7  
 // License as published by the Free Software Foundation; either
 8  
 // version 2.1 of the License, or (at your option) any later version.
 9  
 //
 10  
 // This library is distributed in the hope that it will be useful,
 11  
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 12  
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 13  
 // Lesser General Public License for more details.
 14  
 //
 15  
 // You should have received a copy of the GNU Lesser General Public
 16  
 // License along with this library; if not, write to the Free Software
 17  
 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18  
 ////////////////////////////////////////////////////////////////////////////////
 19  
 
 20  
 package com.puppycrawl.tools.checkstyle.checks.coding;
 21  
 
 22  
 import com.puppycrawl.tools.checkstyle.StatelessCheck;
 23  
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 24  
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 25  
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 26  
 import com.puppycrawl.tools.checkstyle.utils.CheckUtils;
 27  
 
 28  
 /**
 29  
  * <p>
 30  
  * Checks that each variable declaration is in its own statement
 31  
  * and on its own line.
 32  
  * </p>
 33  
  * <p>
 34  
  * Rationale: <a
 35  
  * href="http://www.oracle.com/technetwork/java/javase/documentation/codeconventions-141270.html">
 36  
  * the SUN Code conventions chapter 6.1</a> recommends that
 37  
  * declarations should be one per line.
 38  
  * </p>
 39  
  * <p>
 40  
  * An example of how to configure the check is:
 41  
  * </p>
 42  
  * <pre>
 43  
  * &lt;module name="MultipleVariableDeclarations"/&gt;
 44  
  * </pre>
 45  
  * @author o_sukhodolsky
 46  
  */
 47  
 @StatelessCheck
 48  11
 public class MultipleVariableDeclarationsCheck extends AbstractCheck {
 49  
 
 50  
     /**
 51  
      * A key is pointing to the warning message text in "messages.properties"
 52  
      * file.
 53  
      */
 54  
     public static final String MSG_MULTIPLE = "multiple.variable.declarations";
 55  
 
 56  
     /**
 57  
      * A key is pointing to the warning message text in "messages.properties"
 58  
      * file.
 59  
      */
 60  
     public static final String MSG_MULTIPLE_COMMA = "multiple.variable.declarations.comma";
 61  
 
 62  
     @Override
 63  
     public int[] getAcceptableTokens() {
 64  6
         return getRequiredTokens();
 65  
     }
 66  
 
 67  
     @Override
 68  
     public int[] getDefaultTokens() {
 69  14
         return getRequiredTokens();
 70  
     }
 71  
 
 72  
     @Override
 73  
     public int[] getRequiredTokens() {
 74  34
         return new int[] {TokenTypes.VARIABLE_DEF};
 75  
     }
 76  
 
 77  
     @Override
 78  
     public void visitToken(DetailAST ast) {
 79  20
         DetailAST nextNode = ast.getNextSibling();
 80  
 
 81  20
         if (nextNode != null) {
 82  18
             final boolean isCommaSeparated = nextNode.getType() == TokenTypes.COMMA;
 83  
 
 84  18
             if (isCommaSeparated
 85  15
                 || nextNode.getType() == TokenTypes.SEMI) {
 86  11
                 nextNode = nextNode.getNextSibling();
 87  
             }
 88  
 
 89  18
             if (nextNode != null
 90  17
                     && nextNode.getType() == TokenTypes.VARIABLE_DEF) {
 91  13
                 final DetailAST firstNode = CheckUtils.getFirstNode(ast);
 92  13
                 if (isCommaSeparated) {
 93  
                     // Check if the multiple variable declarations are in a
 94  
                     // for loop initializer. If they are, then no warning
 95  
                     // should be displayed. Declaring multiple variables in
 96  
                     // a for loop initializer is a good way to minimize
 97  
                     // variable scope. Refer Feature Request Id - 2895985
 98  
                     // for more details
 99  3
                     if (ast.getParent().getType() != TokenTypes.FOR_INIT) {
 100  2
                         log(firstNode, MSG_MULTIPLE_COMMA);
 101  
                     }
 102  
                 }
 103  
                 else {
 104  10
                     final DetailAST lastNode = getLastNode(ast);
 105  10
                     final DetailAST firstNextNode = CheckUtils.getFirstNode(nextNode);
 106  
 
 107  10
                     if (firstNextNode.getLineNo() == lastNode.getLineNo()) {
 108  7
                         log(firstNode, MSG_MULTIPLE);
 109  
                     }
 110  
                 }
 111  
             }
 112  
         }
 113  20
     }
 114  
 
 115  
     /**
 116  
      * Finds sub-node for given node maximum (line, column) pair.
 117  
      * @param node the root of tree for search.
 118  
      * @return sub-node with maximum (line, column) pair.
 119  
      */
 120  
     private static DetailAST getLastNode(final DetailAST node) {
 121  76
         DetailAST currentNode = node;
 122  76
         DetailAST child = node.getFirstChild();
 123  142
         while (child != null) {
 124  66
             final DetailAST newNode = getLastNode(child);
 125  66
             if (newNode.getLineNo() > currentNode.getLineNo()
 126  63
                 || newNode.getLineNo() == currentNode.getLineNo()
 127  62
                     && newNode.getColumnNo() > currentNode.getColumnNo()) {
 128  34
                 currentNode = newNode;
 129  
             }
 130  66
             child = child.getNextSibling();
 131  66
         }
 132  
 
 133  76
         return currentNode;
 134  
     }
 135  
 }