Coverage Report - com.puppycrawl.tools.checkstyle.checks.blocks.AvoidNestedBlocksCheck
 
Classes in this File Line Coverage Branch Coverage Complexity
AvoidNestedBlocksCheck
100%
10/10
100%
8/8
2.667
 
 1  
 ////////////////////////////////////////////////////////////////////////////////
 2  
 // checkstyle: Checks Java source code for adherence to a set of rules.
 3  
 // Copyright (C) 2001-2014  Oliver Burn
 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  
 package com.puppycrawl.tools.checkstyle.checks.blocks;
 20  
 
 21  
 import com.puppycrawl.tools.checkstyle.api.Check;
 22  
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 23  
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 24  
 
 25  
 /**
 26  
  * Finds nested blocks.
 27  
  *
 28  
  * <p>
 29  
  * For example this Check flags confusing code like
 30  
  * </p>
 31  
  * <pre>
 32  
  * public void guessTheOutput()
 33  
  * {
 34  
  *     int whichIsWhich = 0;
 35  
  *     {
 36  
  *         int whichIsWhich = 2;
 37  
  *     }
 38  
  *     System.out.println("value = " + whichIsWhich);
 39  
  * }
 40  
  * </pre>
 41  
  *
 42  
  * and debugging / refactoring leftovers such as
 43  
  *
 44  
  * <pre>
 45  
  * // if (someOldCondition)
 46  
  * {
 47  
  *     System.out.println("unconditional");
 48  
  * }
 49  
  * </pre>
 50  
  *
 51  
  * <p>
 52  
  * A case in a switch statement does not implicitly form a block.
 53  
  * Thus to be able to introduce local variables that have case scope
 54  
  * it is necessary to open a nested block. This is supported, set
 55  
  * the allowInSwitchCase property to true and include all statements
 56  
  * of the case in the block.
 57  
  * </p>
 58  
  *
 59  
  * <pre>
 60  
  * switch (a)
 61  
  * {
 62  
  *     case 0:
 63  
  *         // Never OK, break outside block
 64  
  *         {
 65  
  *             x = 1;
 66  
  *         }
 67  
  *         break;
 68  
  *     case 1:
 69  
  *         // Never OK, statement outside block
 70  
  *         System.out.println("Hello");
 71  
  *         {
 72  
  *             x = 2;
 73  
  *             break;
 74  
  *         }
 75  
  *     case 1:
 76  
  *         // OK if allowInSwitchCase is true
 77  
  *         {
 78  
  *             System.out.println("Hello");
 79  
  *             x = 2;
 80  
  *             break;
 81  
  *         }
 82  
  * }
 83  
  * </pre>
 84  
  *
 85  
  * @author lkuehne
 86  
  */
 87  2
 public class AvoidNestedBlocksCheck extends Check
 88  
 {
 89  
     /**
 90  
      * Whether nested blocks are allowed if they are the
 91  
      * only child of a switch case.
 92  
      */
 93  
     private boolean mAllowInSwitchCase;
 94  
 
 95  
     @Override
 96  
     public int[] getDefaultTokens()
 97  
     {
 98  2
         return new int[] {TokenTypes.SLIST};
 99  
     }
 100  
 
 101  
     @Override
 102  
     public void visitToken(DetailAST aAST)
 103  
     {
 104  22
         final DetailAST parent = aAST.getParent();
 105  22
         if (parent.getType() == TokenTypes.SLIST) {
 106  8
             if (mAllowInSwitchCase
 107  
                     && (parent.getParent().getType() == TokenTypes.CASE_GROUP)
 108  
                     && (parent.getNumberOfChildren() == 1))
 109  
             {
 110  1
                 return;
 111  
             }
 112  7
             log(aAST.getLineNo(), aAST.getColumnNo(), "block.nested");
 113  
         }
 114  21
     }
 115  
 
 116  
     /**
 117  
      * Setter for allowInSwitchCase property.
 118  
      * @param aAllowInSwitchCase whether nested blocks are allowed
 119  
      *                 if they are the only child of a switch case.
 120  
      */
 121  
     public void setAllowInSwitchCase(boolean aAllowInSwitchCase)
 122  
     {
 123  1
         mAllowInSwitchCase = aAllowInSwitchCase;
 124  1
     }
 125  
 }