LackOfCohesionOfMethods::calculate() - Code Metrics - Inspection of "[WIP] v2" - phpmetrics/PhpMetrics - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#221)

by personal

created 2016-05-04 05:46 UTC

LackOfCohesionOfMethods::calculate() C

↳ Parent: LackOfCohesionOfMethods

Complexity

Conditions	12
Paths	68

Size

Total Lines	58
Code Lines	28

Duplication

Lines	0
Ratio	0 %

Importance

Changes	3
Bugs	0	Features	0

Metric	Value
cc	12
eloc	28
nc	68
nop	1
dl	0
loc	58
rs	6.5331
c	3
b	0
f	0

How to fix Long Method Complexity

<?php

/*
 * (c) Jean-François Lépine <https://twitter.com/Halleck45>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Hal\Metrics\Complexity\Structural\LCOM;
use Hal\Component\Reflected\Klass;
use Hal\Component\Tree\Graph;
use Hal\Component\Tree\Node;
use Hal\Metrics\ClassMetric;

/**
 * Calculates lack of cohesion method
 *
 * @author Jean-François Lépine <https://twitter.com/Halleck45>
 */
class LackOfCohesionOfMethods implements ClassMetric {


    /**
     * @param Klass $class
     * @return Result
     */
    public function calculate(Klass $class) {

        $graph = new Graph();

        // attributes in graph are prefixed with '_attr_' string
        foreach($class->getMethods() as $method) {

            // avoid getters and setters
            if($method->isGetter() ||$method->isSetter()) {
                continue;
            }

            if(null === ($from = $graph->get($method->getName()))) {
class A
{
    function getObject()
    {
        return null;
    }

}

$a = new A();
$object = $a->getObject();
                $from = new Node($method->getName());
                $graph->insert($from);
            }

            // calls
            foreach($method->getCalls() as $call) {

                if(!$call->isItself()) {
                    continue;

                }

                if(null === ($to = $graph->get($call->getMethodName()))) {
class A
{
    function getObject()
    {
        return null;
    }

}

$a = new A();
$object = $a->getObject();
                    $to = new Node($call->getMethodName());
                    $graph->insert($to);
                }
                $graph->addEdge($from, $to);
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}
            }

            // attributes
            foreach($method->getTokens() as $token) {
                if(preg_match('!\$this\->(\w+)$!', $token, $matches)) {
                    list(, $attribute) = $matches;

                    if(null === ($to = $graph->get('_attr_' . $attribute))) {
class A
{
    function getObject()
    {
        return null;
    }

}

$a = new A();
$object = $a->getObject();
                        $to = new Node('_attr_' . $attribute);
                        $graph->insert($to);
                    }
                    $graph->addEdge($from, $to);
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}
                }
            }

        }

        // iterate over nodes, and count paths
        $paths = 0;
        foreach($graph->all() as $node) {
            $paths += $this->traverse($node);
        }

        $result = new Result;
        $result->setLcom($paths);
        return $result;

    }


    /**
     * Traverse node, and return 1 if node has not been visited yet
     *
     * @param Node $node
     * @return int
     */
    private function traverse(Node $node)
    {
        if($node->visited) {
            return 0;
        }
        $node->visited = true;

        foreach($node->getAdjacents() as $adjacent) {
            $this->traverse($adjacent);
        }

        return 1;
    }
}







1			<?php
2
3			/*
4			* (c) Jean-François Lépine <https://twitter.com/Halleck45>
5			*
6			* For the full copyright and license information, please view the LICENSE
7			* file that was distributed with this source code.
8			*/
9
10			namespace Hal\Metrics\Complexity\Structural\LCOM;
11			use Hal\Component\Reflected\Klass;
12			use Hal\Component\Tree\Graph;
13			use Hal\Component\Tree\Node;
14			use Hal\Metrics\ClassMetric;
15
16			/**
17			* Calculates lack of cohesion method
18			*
19			* @author Jean-François Lépine <https://twitter.com/Halleck45>
20			*/
21			class LackOfCohesionOfMethods implements ClassMetric {
22
23
24			/**
25			* @param Klass $class
26			* @return Result
27			*/
28			public function calculate(Klass $class) {
29
30			$graph = new Graph();
31
32			// attributes in graph are prefixed with '_attr_' string
33			foreach($class->getMethods() as $method) {
34
35			// avoid getters and setters
36			if($method->isGetter() \|\|$method->isSetter()) {
37			continue;
38			}
39
40			if(null === ($from = $graph->get($method->getName()))) {
			0 ignored issues – show Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report Are you sure the assignment to `$from` is correct as `$graph->get($method->getName())` (which targets `Hal\Component\Tree\Graph::get()`) seems to always return null. This check looks for function or method calls that always return null and whose return value is assigned to a variable. class A { function getObject() { return null; } } $a = new A(); $object = $a->getObject(); The method `getObject()` can return nothing but null, so it makes no sense to assign that value to a variable. The reason is most likely that a function or method is imcomplete or has been reduced for debug purposes. Loading history...
41			$from = new Node($method->getName());
42			$graph->insert($from);
43			}
44
45			// calls
46			foreach($method->getCalls() as $call) {
47
48			if(!$call->isItself()) {
49			continue;
50
51			}
52
53			if(null === ($to = $graph->get($call->getMethodName()))) {
			0 ignored issues – show Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report Are you sure the assignment to `$to` is correct as `$graph->get($call->getMethodName())` (which targets `Hal\Component\Tree\Graph::get()`) seems to always return null. This check looks for function or method calls that always return null and whose return value is assigned to a variable. class A { function getObject() { return null; } } $a = new A(); $object = $a->getObject(); The method `getObject()` can return nothing but null, so it makes no sense to assign that value to a variable. The reason is most likely that a function or method is imcomplete or has been reduced for debug purposes. Loading history...
54			$to = new Node($call->getMethodName());
55			$graph->insert($to);
56			}
57			$graph->addEdge($from, $to);
			0 ignored issues – show Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report It seems like `$from` defined by `$graph->get($method->getName())` on line `40` can be `null`; however, `Hal\Component\Tree\Graph::addEdge()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /** @return stdClass\|null / function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history... Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report It seems like `$to` defined by `$graph->get($call->getMethodName())` on line `53` can be `null`; however, `Hal\Component\Tree\Graph::addEdge()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /* @return stdClass\|null */ function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history...
58			}
59
60			// attributes
61			foreach($method->getTokens() as $token) {
62			if(preg_match('!\$this\->(\w+)$!', $token, $matches)) {
63			list(, $attribute) = $matches;
64
65			if(null === ($to = $graph->get('_attr_' . $attribute))) {
			0 ignored issues – show Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report Are you sure the assignment to `$to` is correct as `$graph->get('_attr_' . $attribute)` (which targets `Hal\Component\Tree\Graph::get()`) seems to always return null. This check looks for function or method calls that always return null and whose return value is assigned to a variable. class A { function getObject() { return null; } } $a = new A(); $object = $a->getObject(); The method `getObject()` can return nothing but null, so it makes no sense to assign that value to a variable. The reason is most likely that a function or method is imcomplete or has been reduced for debug purposes. Loading history...
66			$to = new Node('_attr_' . $attribute);
67			$graph->insert($to);
68			}
69			$graph->addEdge($from, $to);
			0 ignored issues – show Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report It seems like `$from` defined by `$graph->get($method->getName())` on line `40` can be `null`; however, `Hal\Component\Tree\Graph::addEdge()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /** @return stdClass\|null / function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history... Bug introduced 2016-05-04 05:49 UTC by Report Bug Copy Issue Report It seems like `$to` defined by `$graph->get('_attr_' . $attribute)` on line `65` can be `null`; however, `Hal\Component\Tree\Graph::addEdge()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /* @return stdClass\|null */ function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history...
70			}
71			}
72
73			}
74
75			// iterate over nodes, and count paths
76			$paths = 0;
77			foreach($graph->all() as $node) {
78			$paths += $this->traverse($node);
79			}
80
81			$result = new Result;
82			$result->setLcom($paths);
83			return $result;
84
85			}
86
87
88			/**
89			* Traverse node, and return 1 if node has not been visited yet
90			*
91			* @param Node $node
92			* @return int
93			*/
94			private function traverse(Node $node)
95			{
96			if($node->visited) {
97			return 0;
98			}
99			$node->visited = true;
100
101			foreach($node->getAdjacents() as $adjacent) {
102			$this->traverse($adjacent);
103			}
104
105			return 1;
106			}
107			}
108
109
110
111
112
113

phpmetrics / PhpMetrics

Pull Request — master (#221)

LackOfCohesionOfMethods::calculate() C

Complexity

Size

Duplication

Importance

How to fix Long Method Complexity

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