Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
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13 | class VotingAssembly implements IVotingAssembly |
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14 | { |
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15 | |||
16 | /** |
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17 | * @var string |
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18 | */ |
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19 | private $strategy; |
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20 | |||
21 | /** |
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22 | * @var IVoter[] |
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23 | */ |
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24 | private $voters; |
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25 | |||
26 | /** |
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27 | * @var string |
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28 | */ |
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29 | private $subjectName; |
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30 | |||
31 | /** |
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32 | * @var string |
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33 | */ |
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34 | private $actionName; |
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35 | |||
36 | |||
37 | /** |
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38 | * VotingAssembly constructor. |
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39 | * @param string $subjectName |
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40 | * @param string $actionName |
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41 | * @param string $strategy |
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42 | * @param \SpareParts\Overseer\Voter\IVoter[] $voters |
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43 | */ |
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44 | public function __construct( |
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55 | |||
56 | |||
57 | 4 | /** |
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58 | 4 | * @param \SpareParts\Overseer\Voter\IVotingSubject $votingSubject |
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59 | 4 | * @param \SpareParts\Overseer\Context\IVotingContext $votingContext |
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60 | 4 | * @return null|\SpareParts\Overseer\IVotingResult |
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61 | 4 | * @throws \SpareParts\Overseer\InvalidVotingResultException |
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62 | 4 | */ |
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63 | public function commenceVote(IVotingSubject $votingSubject, IVotingContext $votingContext) |
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80 | |||
81 | |||
82 | /** |
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83 | * @param \SpareParts\Overseer\Voter\IVotingSubject $votingSubject |
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84 | * @param \SpareParts\Overseer\Context\IVotingContext $votingContext |
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85 | * @return \SpareParts\Overseer\IVotingResult |
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86 | * @throws \SpareParts\Overseer\InvalidVotingResultException |
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87 | */ |
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88 | private function strategyFirstVoteDecides(IVotingSubject $votingSubject, IVotingContext $votingContext) |
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97 | |||
98 | |||
99 | /** |
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100 | * @param \SpareParts\Overseer\Voter\IVotingSubject $votingSubject |
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101 | * @param \SpareParts\Overseer\Context\IVotingContext $votingContext |
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102 | * @return \SpareParts\Overseer\IVotingResult |
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103 | */ |
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104 | View Code Duplication | private function strategyAllowUnlessDenied($votingSubject, $votingContext) |
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117 | |||
118 | |||
119 | /** |
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120 | * @param \SpareParts\Overseer\Voter\IVotingSubject $votingSubject |
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121 | * @param \SpareParts\Overseer\Context\IVotingContext $votingContext |
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122 | * @return \SpareParts\Overseer\IVotingResult |
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123 | */ |
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124 | View Code Duplication | private function strategyDenyUnlessAllowed($votingSubject, $votingContext) |
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137 | |||
138 | |||
139 | /** |
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140 | * @param string $actionName |
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141 | * @param \SpareParts\Overseer\Voter\IVotingSubject $subject |
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142 | * @param \SpareParts\Overseer\Context\IVotingContext $context |
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143 | * @return bool |
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144 | */ |
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145 | public function canVoteOn($actionName, IVotingSubject $subject, IVotingContext $context) |
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152 | } |
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153 |
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVar
assignment in line 1 and the$higher
assignment in line 2 are dead. The first because$myVar
is never used and the second because$higher
is always overwritten for every possible time line.