Coverage Report - com.puppycrawl.tools.checkstyle.checks.naming.LocalVariableNameCheck
 
Classes in this File Line Coverage Branch Coverage Complexity
LocalVariableNameCheck
100%
18/18
100%
16/16
1.571
 
 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.naming;
 21  
 
 22  
 import java.util.regex.Pattern;
 23  
 
 24  
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 25  
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 26  
 import com.puppycrawl.tools.checkstyle.utils.ScopeUtils;
 27  
 
 28  
 /**
 29  
  * <p>
 30  
  * Checks that local, non-final variable names conform to a format specified
 31  
  * by the format property. A catch parameter is considered to be
 32  
  * a local variable. The format is a
 33  
  * {@link Pattern regular expression}
 34  
  * and defaults to
 35  
  * <strong>^[a-z][a-zA-Z0-9]*$</strong>.
 36  
  * </p>
 37  
  * <p>
 38  
  * An example of how to configure the check is:
 39  
  * </p>
 40  
  * <pre>
 41  
  * &lt;module name="LocalVariableName"/&gt;
 42  
  * </pre>
 43  
  * <p>
 44  
  * An example of how to configure the check for names that begin with a lower
 45  
  * case letter, followed by letters, digits, and underscores is:
 46  
  * </p>
 47  
  * <pre>
 48  
  * &lt;module name="LocalVariableName"&gt;
 49  
  *    &lt;property name="format" value="^[a-z](_?[a-zA-Z0-9]+)*$"/&gt;
 50  
  * &lt;/module&gt;
 51  
  * </pre>
 52  
  * <p>
 53  
  * An example of one character variable name in
 54  
  * initialization expression(like "i") in FOR loop:
 55  
  * </p>
 56  
  * <pre>
 57  
  * for(int i = 1; i &lt; 10; i++) {}
 58  
  * </pre>
 59  
  * <p>
 60  
  * An example of how to configure the check to allow one char variable name in
 61  
  * <a href="https://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html">
 62  
  * initialization expressions</a> in FOR loop:
 63  
  * </p>
 64  
  * <pre>
 65  
  * &lt;module name="LocalVariableName"&gt;
 66  
  *    &lt;property name="allowOneCharVarInForLoop" value="true"/&gt;
 67  
  * &lt;/module&gt;
 68  
  * </pre>
 69  
  *
 70  
  * @author Rick Giles
 71  
  * @author maxvetrenko
 72  
  */
 73  
 public class LocalVariableNameCheck
 74  
     extends AbstractNameCheck {
 75  
     /** Regexp for one-char loop variables. */
 76  2
     private static final Pattern SINGLE_CHAR = Pattern.compile("^[a-z]$");
 77  
 
 78  
     /**
 79  
      * Allow one character name for initialization expression in FOR loop.
 80  
      */
 81  
     private boolean allowOneCharVarInForLoop;
 82  
 
 83  
     /** Creates a new {@code LocalVariableNameCheck} instance. */
 84  
     public LocalVariableNameCheck() {
 85  13
         super("^[a-z][a-zA-Z0-9]*$");
 86  13
     }
 87  
 
 88  
     /**
 89  
      * Sets whether to allow one character name in FOR loop or not.
 90  
      *
 91  
      * @param allow Flag for allowing or not one character name in FOR loop.
 92  
      */
 93  
     public final void setAllowOneCharVarInForLoop(boolean allow) {
 94  2
         allowOneCharVarInForLoop = allow;
 95  2
     }
 96  
 
 97  
     @Override
 98  
     public int[] getDefaultTokens() {
 99  17
         return getAcceptableTokens();
 100  
     }
 101  
 
 102  
     @Override
 103  
     public int[] getAcceptableTokens() {
 104  43
         return new int[] {
 105  
             TokenTypes.VARIABLE_DEF,
 106  
         };
 107  
     }
 108  
 
 109  
     @Override
 110  
     public int[] getRequiredTokens() {
 111  20
         return getAcceptableTokens();
 112  
     }
 113  
 
 114  
     @Override
 115  
     protected final boolean mustCheckName(DetailAST ast) {
 116  
         final boolean result;
 117  49
         if (allowOneCharVarInForLoop && isForLoopVariable(ast)) {
 118  4
             final String variableName = ast.findFirstToken(TokenTypes.IDENT).getText();
 119  4
             result = !SINGLE_CHAR.matcher(variableName).find();
 120  4
         }
 121  
         else {
 122  45
             final DetailAST modifiersAST = ast.findFirstToken(TokenTypes.MODIFIERS);
 123  45
             final boolean isFinal = modifiersAST.findFirstToken(TokenTypes.FINAL) != null;
 124  45
             result = !isFinal && ScopeUtils.isLocalVariableDef(ast);
 125  
         }
 126  49
         return result;
 127  
     }
 128  
 
 129  
     /**
 130  
      * Checks if a variable is the loop's one.
 131  
      * @param variableDef variable definition.
 132  
      * @return true if a variable is the loop's one.
 133  
      */
 134  
     private static boolean isForLoopVariable(DetailAST variableDef) {
 135  7
         final int parentType = variableDef.getParent().getType();
 136  7
         return parentType == TokenTypes.FOR_INIT
 137  
                 || parentType == TokenTypes.FOR_EACH_CLAUSE;
 138  
     }
 139  
 }