StringLiteralEqualityCheck.java

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////////////////////////////////////////////////////////////////////////////////
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// checkstyle: Checks Java source code for adherence to a set of rules.
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// Copyright (C) 2001-2018 the original author or authors.
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 2.1 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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// Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License along with this library; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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////////////////////////////////////////////////////////////////////////////////
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package com.puppycrawl.tools.checkstyle.checks.coding;
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import antlr.collections.AST;
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import com.puppycrawl.tools.checkstyle.StatelessCheck;
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import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
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import com.puppycrawl.tools.checkstyle.api.DetailAST;
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import com.puppycrawl.tools.checkstyle.api.TokenTypes;
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/**
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 * <p>Checks that string literals are not used with
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 * {@code ==} or <code>&#33;=</code>.
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 * </p>
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 * <p>
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 * Rationale: Novice Java programmers often use code like
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 * {@code if (x == "something")} when they mean
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 * {@code if ("something".equals(x))}.
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 * </p>
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 *
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 * @author Lars K&uuml;hne
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 * @noinspection HtmlTagCanBeJavadocTag
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 */
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@StatelessCheck
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public class StringLiteralEqualityCheck extends AbstractCheck {
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    /**
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     * A key is pointing to the warning message text in "messages.properties"
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     * file.
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     */
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    public static final String MSG_KEY = "string.literal.equality";
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    @Override
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    public int[] getDefaultTokens() {
52 1 1. getDefaultTokens : mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::getDefaultTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
 
        return getRequiredTokens();
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    }
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    @Override
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    public int[] getAcceptableTokens() {
57 1 1. getAcceptableTokens : mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::getAcceptableTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
 
        return getRequiredTokens();
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    }
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    @Override
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    public int[] getRequiredTokens() {
62 1 1. getRequiredTokens : mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::getRequiredTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
 
        return new int[] {TokenTypes.EQUAL, TokenTypes.NOT_EQUAL};
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    }
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    @Override
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    public void visitToken(DetailAST ast) {
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        // no need to check for nulls here, == and != always have two children
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        final AST firstChild = ast.getFirstChild();
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        final AST secondChild = firstChild.getNextSibling();
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71 1 1. visitToken : negated conditional → KILLED
 
        if (firstChild.getType() == TokenTypes.STRING_LITERAL
72 1 1. visitToken : negated conditional → KILLED
 
                || secondChild.getType() == TokenTypes.STRING_LITERAL) {
73 1 1. visitToken : removed call to com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::log → KILLED
 
            log(ast.getLineNo(), ast.getColumnNo(),
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                    MSG_KEY, ast.getText());
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        }
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    }
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}

Mutations

52

1.1
Location : getDefaultTokens
Killed by : com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest) mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::getDefaultTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
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1.1
Location : getAcceptableTokens
Killed by : com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest) mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::getAcceptableTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
62

1.1
Location : getRequiredTokens
Killed by : com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest.testTokensNotNull(com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest) mutated return of Object value for com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::getRequiredTokens to ( if (x != null) null else throw new RuntimeException ) → KILLED
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1.1
Location : visitToken
Killed by : com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest.testIt(com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest) negated conditional → KILLED
72

1.1
Location : visitToken
Killed by : com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest.testIt(com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest) negated conditional → KILLED
73

1.1
Location : visitToken
Killed by : com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest.testIt(com.puppycrawl.tools.checkstyle.checks.coding.StringLiteralEqualityCheckTest) removed call to com/puppycrawl/tools/checkstyle/checks/coding/StringLiteralEqualityCheck::log → KILLED

Active mutators

Tests examined


Report generated by PIT 1.3.1