CaseExpression - Code Metrics - Inspection of "Add parsing of CASE Expressions" - phpmyadmin/sql-parser - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#88)

by Deven

created 2016-09-26 14:04 UTC

CaseExpression B

↳ Parent: Project

Complexity

Total Complexity

Size/Duplication

Total Lines	225
Duplicated Lines	18.67 %

Coupling/Cohesion

Components	1
Dependencies	5

Importance

Changes

Metric	Value
dl	42
loc	225
rs	8.2608
c	0
b	0
f	0
wmc	40
lcom	1
cbo	5

3 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	3	1
D	parse()	26	132	32
C	build()	16	32	7

How to fix Duplicated Code Complexity

Duplicated Code

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:

If you have the same expression in different places: Extract expression to a method
If you have the same method in different sub-classes: Extract method, and pull up field to the parent class
If you have the same code in unrelated classes: Consider extracting the code to a new class, and injecting that class

Complex Class

Tip: Before tackling complexity, make sure that you eliminate any duplication first. This often can reduce the size of classes significantly.

Complex classes like CaseExpression often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

While breaking up the class, it is a good idea to analyze how other classes use CaseExpression, and based on these observations, apply Extract Interface, too.

<?php

/**
 * Parses a reference to a CASE expression
 *
 * @package    SqlParser
 * @subpackage Components
 */
namespace SqlParser\Components;

use SqlParser\Context;
use SqlParser\Component;
use SqlParser\Parser;
use SqlParser\Token;
use SqlParser\TokensList;


/**
 * Parses a reference to a CASE expression
 *
 * @category   Components
 * @package    SqlParser
 * @subpackage Components
 * @license    http://opensource.org/licenses/GPL-2.0 GNU Public License
 */
class CaseExpression extends Component
{

    /**
     * The value to be compared
     *
     * @var Expression
     */
    public $value;

    /**
     * The conditions in WHEN clauses
     *
     * @var array
     */
    public $conditions;

    /**
     * The results matching with the WHEN clauses
     *
     * @var array
     */
    public $results;

    /**
     * The values to be compared against
     *
     * @var array
     */
    public $compare_values;

    /**
     * The result in ELSE section of expr
     *
     * @var array
     */
    public $else_result;

    /**
     * Constructor.
     *
     */
    public function __construct()
    {
    }

    /**
     *
     * @param Parser     $parser  The parser that serves as context.
     * @param TokensList $list    The list of tokens that are being parsed.
     *
     * @return Expression

     */
    public static function parse(Parser $parser, TokensList $list, array $options = array())
    {
        $ret = new CaseExpression();

        /**
         * State of parser
         *
         * @var int $parser
         */
        $state = 0;

        /**
         * Syntax type (type 0 or type 1)
         *
         * @var int $type
         */
        $type = 0;

        ++$list->idx; // Skip 'CASE'

        for (; $list->idx < $list->count; ++$list->idx) {

            /**
             * Token parsed at this moment.
             *
             * @var Token $token
             */
            $token = $list->tokens[$list->idx];

            // Skipping whitespaces and comments.
            if (($token->type === Token::TYPE_WHITESPACE)
                || ($token->type === Token::TYPE_COMMENT)
            ) {
                continue;
            }

            if ($state === 0) {
                if ($token->type === Token::TYPE_KEYWORD
                    && $token->value === 'WHEN'
                ) {
                    ++$list->idx; // Skip 'WHEN'
                    $new_condition = Condition::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                    $type = 1;
                    $state = 1;
                    $ret->conditions[] = $new_condition;
                } elseif ($token->type === Token::TYPE_KEYWORD
                    && $token->value === 'ELSE'
                ) {
                    ++$list->idx; // Skip 'ELSE'
                    $ret->else_result = Expression::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                    $state = 0; // last clause of CASE expression
                } elseif ($token->type === Token::TYPE_KEYWORD
                    && ($token->value === 'END'
                    || $token->value === 'end')
                ) {
                    $state = 3; // end of CASE expression
                    ++$list->idx;
                    break;
                } elseif ($token->type === Token::TYPE_KEYWORD) {
                    $parser->error(__('Unexpected keyword.'), $token);

                    break;
                } else {
                    $ret->value = Expression::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                    $type = 0;
                    $state = 1;
                }
            } elseif ($state === 1) {
                if ($type === 0) {
                    if ($token->type === Token::TYPE_KEYWORD
                        && $token->value === 'WHEN'
                    ) {
                        ++$list->idx; // Skip 'WHEN'
                        $new_value = Expression::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                        $state = 2;
                        $ret->compare_values[] = $new_value;
                    } elseif ($token->type === Token::TYPE_KEYWORD
                        && $token->value === 'ELSE'
                    ) {
                        ++$list->idx; // Skip 'ELSE'
                        $ret->else_result = Expression::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                        $state = 0; // last clause of CASE expression
                    } elseif ($token->type === Token::TYPE_KEYWORD
                        && ($token->value === 'END'
                        || $token->value === 'end')
                    ) {
                        $state = 3; // end of CASE expression
                        ++$list->idx;
                        break;
                    } elseif ($token->type === Token::TYPE_KEYWORD) {
                        $parser->error(__('Unexpected keyword.'), $token);

                        break;
                    }
                } else {
                    if ($token->type === Token::TYPE_KEYWORD
                        && $token->value === 'THEN'
                    ) {
                        ++$list->idx; // Skip 'THEN'
                        $new_result = Expression::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                        $state = 0;
                        $ret->results[] = $new_result;
                    } elseif ($token->type === Token::TYPE_KEYWORD) {
                        $parser->error(__('Unexpected keyword.'), $token);

                        break;
                    }
                }
            } elseif ($state === 2) {
                if ($type === 0) {
                    if ($token->type === Token::TYPE_KEYWORD
                        && $token->value === 'THEN'
                    ) {
                        ++$list->idx; // Skip 'THEN'
                        $new_result = Expression::parse($parser, $list);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
                        $ret->results[] = $new_result;
                        $state = 1;
                    } elseif ($token->type === Token::TYPE_KEYWORD) {
                        $parser->error(__('Unexpected keyword.'), $token);

                        break;
                    }
                }
            }
        }

        if ($state !== 3) {
            $parser->error(

                __('Unexpected end of CASE expression'),
                $list->tokens[$list->idx - 1]
            );
        }

        --$list->idx;
        return $ret;
    }

    /**
     * @param Expression $component The component to be built.
     * @param array      $options   Parameters for building.
     *
     * @return string
     */
    public static function build($component, array $options = array())
    {
        $ret = 'CASE ';
        if (isset($component->value)) {
            // Syntax type 0
            $ret .= $component->value . ' ';

            for (
                $i = 0;
                $i < count($component->compare_values) && $i < count($component->results);

                $i++
            ) {
                $ret .= 'WHEN ' . $component->compare_values[$i] . ' ';
                $ret .= 'THEN ' . $component->results[$i] . ' ';
            }
        } else {
            // Syntax type 1
            for (
                $i = 0;
                $i < count($component->conditions) && $i < count($component->results);

                $i++
            ) {
                $ret .= 'WHEN ' . Condition::build($component->conditions[$i]) . ' ';
                $ret .= 'THEN ' . $component->results[$i] . ' ';
            }
        }
        if (isset($component->else_result)) {
            $ret .= 'ELSE ' . $component->else_result . ' ';

        }
        $ret .= 'END';

        return $ret;
    }
}


1		<?php
2
3		/**
4		* Parses a reference to a CASE expression
5		*
6		* @package SqlParser
7		* @subpackage Components
8		*/
9		namespace SqlParser\Components;
10
11		use SqlParser\Context;
12		use SqlParser\Component;
13		use SqlParser\Parser;
14		use SqlParser\Token;
15		use SqlParser\TokensList;
16
17
18		/**
19		* Parses a reference to a CASE expression
20		*
21		* @category Components
22		* @package SqlParser
23		* @subpackage Components
24		* @license http://opensource.org/licenses/GPL-2.0 GNU Public License
25		*/
26		class CaseExpression extends Component
27		{
28
29		/**
30		* The value to be compared
31		*
32		* @var Expression
33		*/
34		public $value;
35
36		/**
37		* The conditions in WHEN clauses
38		*
39		* @var array
40		*/
41		public $conditions;
42
43		/**
44		* The results matching with the WHEN clauses
45		*
46		* @var array
47		*/
48		public $results;
49
50		/**
51		* The values to be compared against
52		*
53		* @var array
54		*/
55		public $compare_values;
56
57		/**
58		* The result in ELSE section of expr
59		*
60		* @var array
61		*/
62		public $else_result;
63
64		/**
65		* Constructor.
66		*
67		*/
68		public function __construct()
69		{
70		}
71
72		/**
73		*
74		* @param Parser $parser The parser that serves as context.
75		* @param TokensList $list The list of tokens that are being parsed.
76		*
77		* @return Expression
		0 ignored issues – show Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report Should the return type not be `CaseExpression`? This check compares the return type specified in the `@return` annotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch. Loading history...
78		*/
79		public static function parse(Parser $parser, TokensList $list, array $options = array())
80		{
81		$ret = new CaseExpression();
82
83		/**
84		* State of parser
85		*
86		* @var int $parser
87		*/
88		$state = 0;
89
90		/**
91		* Syntax type (type 0 or type 1)
92		*
93		* @var int $type
94		*/
95		$type = 0;
96
97		++$list->idx; // Skip 'CASE'
98
99		for (; $list->idx < $list->count; ++$list->idx) {
100
101		/**
102		* Token parsed at this moment.
103		*
104		* @var Token $token
105		*/
106		$token = $list->tokens[$list->idx];
107
108		// Skipping whitespaces and comments.
109		if (($token->type === Token::TYPE_WHITESPACE)
110		\|\| ($token->type === Token::TYPE_COMMENT)
111		) {
112		continue;
113		}
114
115		if ($state === 0) {
116		if ($token->type === Token::TYPE_KEYWORD
117		&& $token->value === 'WHEN'
118		) {
119		++$list->idx; // Skip 'WHEN'
120		$new_condition = Condition::parse($parser, $list);
		0 ignored issues – show Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
121		$type = 1;
122		$state = 1;
123		$ret->conditions[] = $new_condition;
124		} elseif ($token->type === Token::TYPE_KEYWORD
125		&& $token->value === 'ELSE'
126		) {
127		++$list->idx; // Skip 'ELSE'
128		$ret->else_result = Expression::parse($parser, $list);
		0 ignored issues – show Documentation Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report It seems like `\SqlParser\Components\Ex...::parse($parser, $list)` of type `object<SqlParser\Components\Expression>` or `null` is incompatible with the declared type `array` of property `$else_result`. Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property. Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property.. Loading history... Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
129		$state = 0; // last clause of CASE expression
130		} elseif ($token->type === Token::TYPE_KEYWORD
131		&& ($token->value === 'END'
132		\|\| $token->value === 'end')
133		) {
134		$state = 3; // end of CASE expression
135		++$list->idx;
136		break;
137		} elseif ($token->type === Token::TYPE_KEYWORD) {
138		$parser->error(__('Unexpected keyword.'), $token);
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The method `error` cannot be called on `$parser` (of type `integer`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
139		break;
140		} else {
141		$ret->value = Expression::parse($parser, $list);
		0 ignored issues – show Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
142		$type = 0;
143		$state = 1;
144		}
145		} elseif ($state === 1) {
146		if ($type === 0) {
147		if ($token->type === Token::TYPE_KEYWORD
148		&& $token->value === 'WHEN'
149		) {
150		++$list->idx; // Skip 'WHEN'
151		$new_value = Expression::parse($parser, $list);
		0 ignored issues – show Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
152		$state = 2;
153		$ret->compare_values[] = $new_value;
154		} elseif ($token->type === Token::TYPE_KEYWORD
155		&& $token->value === 'ELSE'
156		) {
157		++$list->idx; // Skip 'ELSE'
158		$ret->else_result = Expression::parse($parser, $list);
		0 ignored issues – show Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
159		$state = 0; // last clause of CASE expression
160		} elseif ($token->type === Token::TYPE_KEYWORD
161		&& ($token->value === 'END'
162		\|\| $token->value === 'end')
163		) {
164		$state = 3; // end of CASE expression
165		++$list->idx;
166		break;
167		} elseif ($token->type === Token::TYPE_KEYWORD) {
168		$parser->error(__('Unexpected keyword.'), $token);
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The method `error` cannot be called on `$parser` (of type `integer`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
169		break;
170		}
171	View Code Duplication	} else {
172		if ($token->type === Token::TYPE_KEYWORD
173		&& $token->value === 'THEN'
174		) {
175		++$list->idx; // Skip 'THEN'
176		$new_result = Expression::parse($parser, $list);
		0 ignored issues – show Documentation introduced 2016-09-26 12:20 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
177		$state = 0;
178		$ret->results[] = $new_result;
179		} elseif ($token->type === Token::TYPE_KEYWORD) {
180		$parser->error(__('Unexpected keyword.'), $token);
		0 ignored issues – show Bug introduced 2016-09-26 10:10 UTC by Report Bug Copy Issue Report The method `error` cannot be called on `$parser` (of type `integer`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
181		break;
182		}
183		}
184		} elseif ($state === 2) {
185	View Code Duplication	if ($type === 0) {
186		if ($token->type === Token::TYPE_KEYWORD
187		&& $token->value === 'THEN'
188		) {
189		++$list->idx; // Skip 'THEN'
190		$new_result = Expression::parse($parser, $list);
		0 ignored issues – show Documentation introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report `$parser` is of type `integer`, but the function expects a `object<SqlParser\Parser>`. It seems like the type of the argument is not accepted by the function/method which you are calling. In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug. We suggest to add an explicit type cast like in the following example: function acceptsInteger($int) { } $x = '123'; // string "123" // Instead of acceptsInteger($x); // we recommend to use acceptsInteger((integer) $x); Loading history...
191		$ret->results[] = $new_result;
192		$state = 1;
193		} elseif ($token->type === Token::TYPE_KEYWORD) {
194		$parser->error(__('Unexpected keyword.'), $token);
		0 ignored issues – show Bug introduced 2016-09-26 10:10 UTC by Report Bug Copy Issue Report The method `error` cannot be called on `$parser` (of type `integer`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
195		break;
196		}
197		}
198		}
199		}
200
201		if ($state !== 3) {
202		$parser->error(
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The method `error` cannot be called on `$parser` (of type `integer`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
203		__('Unexpected end of CASE expression'),
204		$list->tokens[$list->idx - 1]
205		);
206		}
207
208		--$list->idx;
209		return $ret;
210		}
211
212		/**
213		* @param Expression $component The component to be built.
214		* @param array $options Parameters for building.
215		*
216		* @return string
217		*/
218		public static function build($component, array $options = array())
219		{
220		$ret = 'CASE ';
221		if (isset($component->value)) {
222		// Syntax type 0
223		$ret .= $component->value . ' ';
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The property `value` does not seem to exist in `SqlParser\Components\Expression`. An attempt at access to an undefined property has been detected. This may either be a typographical error or the property has been renamed but there are still references to its old name. If you really want to allow access to undefined properties, you can define magic methods to allow access. See the php core documentation on Overloading. Loading history...
224	View Code Duplication	for (
225		$i = 0;
226		$i < count($component->compare_values) && $i < count($component->results);
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The property `compare_values` does not seem to exist in `SqlParser\Components\Expression`. An attempt at access to an undefined property has been detected. This may either be a typographical error or the property has been renamed but there are still references to its old name. If you really want to allow access to undefined properties, you can define magic methods to allow access. See the php core documentation on Overloading. Loading history... Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The property `results` does not seem to exist in `SqlParser\Components\Expression`. An attempt at access to an undefined property has been detected. This may either be a typographical error or the property has been renamed but there are still references to its old name. If you really want to allow access to undefined properties, you can define magic methods to allow access. See the php core documentation on Overloading. Loading history...
227		$i++
228		) {
229		$ret .= 'WHEN ' . $component->compare_values[$i] . ' ';
230		$ret .= 'THEN ' . $component->results[$i] . ' ';
231		}
232		} else {
233		// Syntax type 1
234	View Code Duplication	for (
235		$i = 0;
236		$i < count($component->conditions) && $i < count($component->results);
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The property `conditions` does not seem to exist in `SqlParser\Components\Expression`. An attempt at access to an undefined property has been detected. This may either be a typographical error or the property has been renamed but there are still references to its old name. If you really want to allow access to undefined properties, you can define magic methods to allow access. See the php core documentation on Overloading. Loading history...
237		$i++
238		) {
239		$ret .= 'WHEN ' . Condition::build($component->conditions[$i]) . ' ';
240		$ret .= 'THEN ' . $component->results[$i] . ' ';
241		}
242		}
243		if (isset($component->else_result)) {
244		$ret .= 'ELSE ' . $component->else_result . ' ';
		0 ignored issues – show Bug introduced 2016-09-25 18:25 UTC by Report Bug Copy Issue Report The property `else_result` does not seem to exist in `SqlParser\Components\Expression`. An attempt at access to an undefined property has been detected. This may either be a typographical error or the property has been renamed but there are still references to its old name. If you really want to allow access to undefined properties, you can define magic methods to allow access. See the php core documentation on Overloading. Loading history...
245		}
246		$ret .= 'END';
247
248		return $ret;
249		}
250		}
251

phpmyadmin / sql-parser