Coverage Report - com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheck
 
Classes in this File Line Coverage Branch Coverage Complexity
ArrayTrailingCommaCheck
100%
13/13
100%
10/10
2.25
 
 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  
 
 27  
 /**
 28  
  * <p>
 29  
  * Checks if array initialization contains optional trailing comma.
 30  
  * </p>
 31  
  * <p>
 32  
  * Rationale: Putting this comma in make is easier to change the
 33  
  * order of the elements or add new elements on the end. Main benefit of a trailing
 34  
  * comma is that when you add new entry to an array, no surrounding lines are changed.
 35  
  * </p>
 36  
  * <p>
 37  
  * The check demands a comma at the end if neither left nor right curly braces
 38  
  * are on the same line as the last element of the array.
 39  
  * </p>
 40  
  * <pre>
 41  
  * return new int[] { 0 };
 42  
  * return new int[] { 0
 43  
  *     };
 44  
  * return new int[] {
 45  
  *     0 };
 46  
  * </pre>
 47  
  * <pre>
 48  
  * {
 49  
  *     100000000000000000000,
 50  
  *     200000000000000000000, // OK
 51  
  * }
 52  
  *
 53  
  * {
 54  
  *     100000000000000000000,
 55  
  *     200000000000000000000,
 56  
  *     300000000000000000000,  // Just this line added, no other changes
 57  
  * }
 58  
  * </pre>
 59  
  * <p>
 60  
  * If closing brace is on the same line as training comma, this benefit is gone
 61  
  * (as the Check does not demand a certain location of curly braces the following
 62  
  * two cases will not produce a violation):
 63  
  * </p>
 64  
  * <pre>
 65  
  * {100000000000000000000,
 66  
  *     200000000000000000000,} // Trailing comma not needed, line needs to be modified anyway
 67  
  *
 68  
  * {100000000000000000000,
 69  
  *     200000000000000000000, // Modified line
 70  
  *     300000000000000000000,} // Added line
 71  
  * </pre>
 72  
  * <p>
 73  
  * If opening brace is on the same line as training comma there's also (more arguable) problem:
 74  
  * </p>
 75  
  * <pre>
 76  
  * {100000000000000000000, // Line cannot be just duplicated to slightly modify entry
 77  
  * }
 78  
  *
 79  
  * {100000000000000000000,
 80  
  *     100000000000000000001, // More work needed to duplicate
 81  
  * }
 82  
  * </pre>
 83  
  * <p>
 84  
  * An example of how to configure the check is:
 85  
  * </p>
 86  
  * <pre>
 87  
  * &lt;module name="ArrayTrailingComma"/&gt;
 88  
  * </pre>
 89  
  * @author o_sukhodolsky
 90  
  */
 91  
 @StatelessCheck
 92  9
 public class ArrayTrailingCommaCheck extends AbstractCheck {
 93  
 
 94  
     /**
 95  
      * A key is pointing to the warning message text in "messages.properties"
 96  
      * file.
 97  
      */
 98  
     public static final String MSG_KEY = "array.trailing.comma";
 99  
 
 100  
     @Override
 101  
     public int[] getDefaultTokens() {
 102  11
         return getRequiredTokens();
 103  
     }
 104  
 
 105  
     @Override
 106  
     public int[] getAcceptableTokens() {
 107  5
         return getRequiredTokens();
 108  
     }
 109  
 
 110  
     @Override
 111  
     public int[] getRequiredTokens() {
 112  27
         return new int[] {TokenTypes.ARRAY_INIT};
 113  
     }
 114  
 
 115  
     @Override
 116  
     public void visitToken(DetailAST arrayInit) {
 117  26
         final DetailAST rcurly = arrayInit.findFirstToken(TokenTypes.RCURLY);
 118  26
         final DetailAST previousSibling = rcurly.getPreviousSibling();
 119  
 
 120  26
         if (arrayInit.getLineNo() != rcurly.getLineNo()
 121  11
                 && arrayInit.getChildCount() != 1
 122  10
                 && rcurly.getLineNo() != previousSibling.getLineNo()
 123  7
                 && arrayInit.getLineNo() != previousSibling.getLineNo()
 124  6
                 && previousSibling.getType() != TokenTypes.COMMA) {
 125  2
             log(rcurly.getLineNo(), MSG_KEY);
 126  
         }
 127  26
     }
 128  
 }