ArrayTrailingCommaCheck.java

////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2018 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.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;

/**
 * <p>
 * Checks if array initialization contains optional trailing comma.
 * </p>
 * <p>
 * Rationale: Putting this comma in make is easier to change the
 * order of the elements or add new elements on the end. Main benefit of a trailing
 * comma is that when you add new entry to an array, no surrounding lines are changed.
 * </p>
 * <p>
 * The check demands a comma at the end if neither left nor right curly braces
 * are on the same line as the last element of the array.
 * </p>
 * <pre>
 * return new int[] { 0 };
 * return new int[] { 0
 *     };
 * return new int[] {
 *     0 };
 * </pre>
 * <pre>
 * {
 *     100000000000000000000,
 *     200000000000000000000, // OK
 * }
 *
 * {
 *     100000000000000000000,
 *     200000000000000000000,
 *     300000000000000000000,  // Just this line added, no other changes
 * }
 * </pre>
 * <p>
 * If closing brace is on the same line as training comma, this benefit is gone
 * (as the Check does not demand a certain location of curly braces the following
 * two cases will not produce a violation):
 * </p>
 * <pre>
 * {100000000000000000000,
 *     200000000000000000000,} // Trailing comma not needed, line needs to be modified anyway
 *
 * {100000000000000000000,
 *     200000000000000000000, // Modified line
 *     300000000000000000000,} // Added line
 * </pre>
 * <p>
 * If opening brace is on the same line as training comma there's also (more arguable) problem:
 * </p>
 * <pre>
 * {100000000000000000000, // Line cannot be just duplicated to slightly modify entry
 * }
 *
 * {100000000000000000000,
 *     100000000000000000001, // More work needed to duplicate
 * }
 * </pre>
 * <p>
 * An example of how to configure the check is:
 * </p>
 * <pre>
 * &lt;module name="ArrayTrailingComma"/&gt;
 * </pre>
 * @author o_sukhodolsky
 */
@StatelessCheck
public class ArrayTrailingCommaCheck extends AbstractCheck {

    /**
     * A key is pointing to the warning message text in "messages.properties"
     * file.
     */
    public static final String MSG_KEY = "array.trailing.comma";

    @Override
    public int[] getDefaultTokens() {
        return getRequiredTokens();
    }

    @Override
    public int[] getAcceptableTokens() {
        return getRequiredTokens();
    }

    @Override
    public int[] getRequiredTokens() {
        return new int[] {TokenTypes.ARRAY_INIT};
    }

    @Override
    public void visitToken(DetailAST arrayInit) {
        final DetailAST rcurly = arrayInit.findFirstToken(TokenTypes.RCURLY);
        final DetailAST previousSibling = rcurly.getPreviousSibling();

        if (arrayInit.getLineNo() != rcurly.getLineNo()
                && arrayInit.getChildCount() != 1
                && rcurly.getLineNo() != previousSibling.getLineNo()
                && arrayInit.getLineNo() != previousSibling.getLineNo()
                && previousSibling.getType() != TokenTypes.COMMA) {
            log(rcurly.getLineNo(), MSG_KEY);
        }
    }

}











Active mutators

INCREMENTS_MUTATOR
VOID_METHOD_CALL_MUTATOR
RETURN_VALS_MUTATOR
MATH_MUTATOR
NEGATE_CONDITIONALS_MUTATOR
INVERT_NEGS_MUTATOR
CONDITIONALS_BOUNDARY_MUTATOR

Tests examined

com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) (351 ms)
com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) (0 ms)

Report generated by PIT 1.3.1

1		////////////////////////////////////////////////////////////////////////////////
2		// checkstyle: Checks Java source code for adherence to a set of rules.
3		// Copyright (C) 2001-2018 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		* <module name="ArrayTrailingComma"/>
88		* </pre>
89		* @author o_sukhodolsky
90		*/
91		@StatelessCheck
92		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	1 1. getDefaultTokens : mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::getDefaultTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED	return getRequiredTokens();
103		}
104
105		@Override
106		public int[] getAcceptableTokens() {
107	1 1. getAcceptableTokens : mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::getAcceptableTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED	return getRequiredTokens();
108		}
109
110		@Override
111		public int[] getRequiredTokens() {
112	1 1. getRequiredTokens : mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::getRequiredTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED	return new int[] {TokenTypes.ARRAY_INIT};
113		}
114
115		@Override
116		public void visitToken(DetailAST arrayInit) {
117		final DetailAST rcurly = arrayInit.findFirstToken(TokenTypes.RCURLY);
118		final DetailAST previousSibling = rcurly.getPreviousSibling();
119
120	1 1. visitToken : negated conditional → KILLED	if (arrayInit.getLineNo() != rcurly.getLineNo()
121	1 1. visitToken : negated conditional → KILLED	&& arrayInit.getChildCount() != 1
122	1 1. visitToken : negated conditional → KILLED	&& rcurly.getLineNo() != previousSibling.getLineNo()
123	1 1. visitToken : negated conditional → KILLED	&& arrayInit.getLineNo() != previousSibling.getLineNo()
124	1 1. visitToken : negated conditional → KILLED	&& previousSibling.getType() != TokenTypes.COMMA) {
125	1 1. visitToken : removed call to com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::log → KILLED	log(rcurly.getLineNo(), MSG_KEY);
126		}
127		}
128
129		}
		Mutations
102		1.1 Location : getDefaultTokens Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::getDefaultTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
107		1.1 Location : getAcceptableTokens Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::getAcceptableTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
112		1.1 Location : getRequiredTokens Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::getRequiredTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
120		1.1 Location : visitToken Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) negated conditional → KILLED
121		1.1 Location : visitToken Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) negated conditional → KILLED
122		1.1 Location : visitToken Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) negated conditional → KILLED
123		1.1 Location : visitToken Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) negated conditional → KILLED
124		1.1 Location : visitToken Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) negated conditional → KILLED
125		1.1 Location : visitToken Killed by : com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest.testDefault(com.puppycrawl.tools.checkstyle.checks.coding.ArrayTrailingCommaCheckTest) removed call to com/puppycrawl/tools/checkstyle/checks/coding/ArrayTrailingCommaCheck::log → KILLED

ArrayTrailingCommaCheck.java

Mutations

Active mutators

Tests examined