Sniffer::setPossibleDelimiters() - Code Metrics - Inspection of "Release v0.3" - nozavroni/csvelte - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#183)

by Luke

created 2018-07-20 00:54 UTC

Sniffer::setPossibleDelimiters() A

↳ Parent: Sniffer

Complexity

Conditions	1
Paths	1

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	8
CRAP Score	1

Importance

Changes

Metric	Value
cc	1
nc	1
nop	1
dl	0
loc	11
ccs	8
cts	8
cp	1
crap	1
rs	9.9
c	0
b	0
f	0

<?php
/**
 * CSVelte: Slender, elegant CSV for PHP
 *
 * Inspired by Python's CSV module and Frictionless Data and the W3C's CSV
 * standardization efforts, CSVelte was written in an effort to take all the
 * suck out of working with CSV.
 *
 * @copyright Copyright (c) 2018 Luke Visinoni
 * @author    Luke Visinoni <[email protected]>
 * @license   See LICENSE file (MIT license)
 */
namespace CSVelte;

use CSVelte\Contract\Streamable;

use CSVelte\Exception\SnifferException;
use CSVelte\Sniffer\SniffDelimiterByConsistency;
use CSVelte\Sniffer\SniffDelimiterByDistribution;
use CSVelte\Sniffer\SniffLineTerminatorByCount;
use CSVelte\Sniffer\SniffQuoteAndDelimByAdjacency;
use Noz\Collection\Collection;
use function Noz\to_array;
use RuntimeException;

use function Noz\collect;
use function Stringy\create as s;

class Sniffer
{
    /** CSV data sample size - sniffer will use this many bytes to make its determinations */
    const SAMPLE_SIZE = 2500;

    /**
     * ASCII character codes for "invisibles".
     */
    const HORIZONTAL_TAB  = 9;
    const LINE_FEED       = 10;
    const CARRIAGE_RETURN = 13;
    const SPACE           = 32;

    /**
     * @var array A list of possible delimiters to check for (in order of preference)
     */
    protected $delims = [',', "\t", ';', '|', ':', '-', '_', '#', '/', '\\', '$', '+', '=', '&', '@'];

    /**
     * @var Streamable A stream of the sample data
     */
    protected $stream;

    /**
     * Sniffer constructor.
     *
     * @param Streamable $stream The data to sniff
     * @param array $delims A list of possible delimiter characters in order of preference
     */
    public function __construct(Streamable $stream, $delims = null)
    {
        $this->stream = $stream;
        if (!is_null($delims)) {
            $this->setPossibleDelimiters($delims);
        }
    }

    /**
     * Set possible delimiter characters
     *
     * @param array $delims A list of possible delimiter characters
     *
     * @return self
     */
    public function setPossibleDelimiters(array $delims)
    {
        $this->delims = collect($delims)
            ->filter(function($val) {
                return s($val)->length() == 1;
            })
            ->values()
            ->toArray();

        return $this;
    }

    /**
     * Get list of possible delimiter characters
     *
     * @return array
     */
    public function getPossibleDelimiters()
    {
        return $this->delims;
    }

    /**
     * Sniff CSV data (determine its dialect)
     *
     * Since CSV is less a format than a collection of similar formats, you can never be certain how a particular CSV
     * file is formatted. This method inspects CSV data and returns its "dialect", an object that can be passed to
     * either a `CSVelte\Reader` or `CSVelte\Writer` object to tell it what "dialect" of CSV to use.
     *
     * @todo look into which other Dialect attributes you can sniff for
     *
     * @return Dialect
     */
    public function sniff()
    {
        $sample = $this->stream->read(static::SAMPLE_SIZE);
        $lineTerminator = $this->sniffLineTerminator($sample);
<?php

function getDate($date)
{
    if ($date !== null) {
        return new DateTime($date);
    }

    return false;
}
        try {
            list($quoteChar, $delimiter) = $this->sniffQuoteAndDelim($sample, $lineTerminator);

        } catch (SnifferException $e) {
            if ($e->getCode() !== SnifferException::ERR_QUOTE_AND_DELIM) {
                throw $e;
            }
            $quoteChar = '"';
            $delimiter = $this->sniffDelimiter($sample, $lineTerminator);
        }
        /**
         * @todo Should this be null? Because doubleQuote = true means this = null
         */
        $escapeChar = '\\';
        $quoteStyle = $this->sniffQuotingStyle($delimiter, $lineTerminator);
        $header     = $this->sniffHeader($delimiter, $lineTerminator);
        $encoding   = s($sample)->getEncoding();

        return new Dialect(compact('quoteChar', 'escapeChar', 'delimiter', 'lineTerminator', 'quoteStyle', 'header', 'encoding'));
    }

    /**
     * Sniff sample data for line terminator character
     *
     * @param string $data The sample data
     *
     * @return string
     */
    protected function sniffLineTerminator($data)
    {
        $sniffer = new SniffLineTerminatorByCount();
        return $sniffer->sniff($data);
    }

    /**
     * Sniff quote and delimiter chars
     *
     * The best way to determine quote and delimiter characters is when columns
     * are quoted, often you can seek out a pattern of delim, quote, stuff, quote, delim
     * but this only works if you have quoted columns. If you don't you have to
     * determine these characters some other way... (see lickDelimiter).
     *
     * @throws SnifferException
     *
     * @param string $data The data to analyze
     * @param string $lineTerminator The line terminator char/sequence
     *
     * @return array A two-row array containing quotechar, delimchar
     */
    protected function sniffQuoteAndDelim($data, $lineTerminator)
    {
        $sniffer = new SniffQuoteAndDelimByAdjacency(compact('lineTerminator'));
        return $sniffer->sniff($data);
    }

    /**
     * @todo To make this class more oop and test-friendly, implement strategy pattern here with each delim sniffing method implemented in its own strategy class.
     */
    protected function sniffDelimiter($data, $lineTerminator)
    {
        $delimiters = $this->getPossibleDelimiters();
        $consistency = new SniffDelimiterByConsistency(compact('lineTerminator', 'delimiters'));
        $winners = $consistency->sniff($data);
        if (count($winners) > 1) {
            $delimiters = $winners;
            return (new SniffDelimiterByDistribution(compact('lineTerminator', 'delimiters')))
                ->sniff($data);
        }
        return current($winners);
    }

    protected function sniffQuotingStyle($delimiter, $eols)

    {
        return Dialect::QUOTE_MINIMAL;
    }

    protected function sniffHeader($delimiter, $eols)

    {
        return true;
    }
}


1		<?php
2		/**
3		* CSVelte: Slender, elegant CSV for PHP
4		*
5		* Inspired by Python's CSV module and Frictionless Data and the W3C's CSV
6		* standardization efforts, CSVelte was written in an effort to take all the
7		* suck out of working with CSV.
8		*
9		* @copyright Copyright (c) 2018 Luke Visinoni
10		* @author Luke Visinoni <[email protected]>
11		* @license See LICENSE file (MIT license)
12		*/
13		namespace CSVelte;
14
15		use CSVelte\Contract\Streamable;
16
17		use CSVelte\Exception\SnifferException;
18		use CSVelte\Sniffer\SniffDelimiterByConsistency;
19		use CSVelte\Sniffer\SniffDelimiterByDistribution;
20		use CSVelte\Sniffer\SniffLineTerminatorByCount;
21		use CSVelte\Sniffer\SniffQuoteAndDelimByAdjacency;
22		use Noz\Collection\Collection;
23		use function Noz\to_array;
24		use RuntimeException;
25
26		use function Noz\collect;
27		use function Stringy\create as s;
28
29		class Sniffer
30		{
31		/** CSV data sample size - sniffer will use this many bytes to make its determinations */
32		const SAMPLE_SIZE = 2500;
33
34		/**
35		* ASCII character codes for "invisibles".
36		*/
37		const HORIZONTAL_TAB = 9;
38		const LINE_FEED = 10;
39		const CARRIAGE_RETURN = 13;
40		const SPACE = 32;
41
42		/**
43		* @var array A list of possible delimiters to check for (in order of preference)
44		*/
45		protected $delims = [',', "\t", ';', '\|', ':', '-', '_', '#', '/', '\\', '$', '+', '=', '&', '@'];
46
47		/**
48		* @var Streamable A stream of the sample data
49		*/
50		protected $stream;
51
52		/**
53		* Sniffer constructor.
54		*
55		* @param Streamable $stream The data to sniff
56		* @param array $delims A list of possible delimiter characters in order of preference
57		*/
58	1	public function __construct(Streamable $stream, $delims = null)
59		{
60	1	$this->stream = $stream;
61	1	if (!is_null($delims)) {
62	1	$this->setPossibleDelimiters($delims);
63	1	}
64	1	}
65
66		/**
67		* Set possible delimiter characters
68		*
69		* @param array $delims A list of possible delimiter characters
70		*
71		* @return self
72		*/
73	1	public function setPossibleDelimiters(array $delims)
74		{
75	1	$this->delims = collect($delims)
76	1	->filter(function($val) {
77	1	return s($val)->length() == 1;
78	1	})
79	1	->values()
80	1	->toArray();
81
82	1	return $this;
83		}
84
85		/**
86		* Get list of possible delimiter characters
87		*
88		* @return array
89		*/
90	1	public function getPossibleDelimiters()
91		{
92	1	return $this->delims;
93		}
94
95		/**
96		* Sniff CSV data (determine its dialect)
97		*
98		* Since CSV is less a format than a collection of similar formats, you can never be certain how a particular CSV
99		* file is formatted. This method inspects CSV data and returns its "dialect", an object that can be passed to
100		* either a `CSVelte\Reader` or `CSVelte\Writer` object to tell it what "dialect" of CSV to use.
101		*
102		* @todo look into which other Dialect attributes you can sniff for
103		*
104		* @return Dialect
105		*/
106		public function sniff()
107		{
108		$sample = $this->stream->read(static::SAMPLE_SIZE);
109		$lineTerminator = $this->sniffLineTerminator($sample);
		0 ignored issues – show Security Bug introduced 2018-07-14 08:04 UTC by Report Bug Copy Issue Report It seems like `$sample` defined by `$this->stream->read(static::SAMPLE_SIZE)` on line `108` can also be of type `false`; however, `CSVelte\Sniffer::sniffLineTerminator()` does only seem to accept `string`, did you maybe forget to handle an error condition? This check looks for type mismatches where the missing type is `false`. This is usually indicative of an error condtion. Consider the follow example <?php function getDate($date) { if ($date !== null) { return new DateTime($date); } return false; } This function either returns a new `DateTime` object or false, if there was an error. This is a typical pattern in PHP programming to show that an error has occurred without raising an exception. The calling code should check for this returned `false` before passing on the value to another function or method that may not be able to handle a `false`. Loading history...
110		try {
111		list($quoteChar, $delimiter) = $this->sniffQuoteAndDelim($sample, $lineTerminator);
		0 ignored issues – show Security Bug introduced 2018-07-14 08:04 UTC by Report Bug Copy Issue Report It seems like `$sample` can also be of type `false`; however, `CSVelte\Sniffer::sniffQuoteAndDelim()` does only seem to accept `string`, did you maybe forget to handle an error condition? Loading history...
112		} catch (SnifferException $e) {
113		if ($e->getCode() !== SnifferException::ERR_QUOTE_AND_DELIM) {
114		throw $e;
115		}
116		$quoteChar = '"';
117		$delimiter = $this->sniffDelimiter($sample, $lineTerminator);
118		}
119		/**
120		* @todo Should this be null? Because doubleQuote = true means this = null
121		*/
122		$escapeChar = '\\';
123		$quoteStyle = $this->sniffQuotingStyle($delimiter, $lineTerminator);
124		$header = $this->sniffHeader($delimiter, $lineTerminator);
125		$encoding = s($sample)->getEncoding();
126
127		return new Dialect(compact('quoteChar', 'escapeChar', 'delimiter', 'lineTerminator', 'quoteStyle', 'header', 'encoding'));
128		}
129
130		/**
131		* Sniff sample data for line terminator character
132		*
133		* @param string $data The sample data
134		*
135		* @return string
136		*/
137		protected function sniffLineTerminator($data)
138		{
139		$sniffer = new SniffLineTerminatorByCount();
140		return $sniffer->sniff($data);
141		}
142
143		/**
144		* Sniff quote and delimiter chars
145		*
146		* The best way to determine quote and delimiter characters is when columns
147		* are quoted, often you can seek out a pattern of delim, quote, stuff, quote, delim
148		* but this only works if you have quoted columns. If you don't you have to
149		* determine these characters some other way... (see lickDelimiter).
150		*
151		* @throws SnifferException
152		*
153		* @param string $data The data to analyze
154		* @param string $lineTerminator The line terminator char/sequence
155		*
156		* @return array A two-row array containing quotechar, delimchar
157		*/
158		protected function sniffQuoteAndDelim($data, $lineTerminator)
159		{
160		$sniffer = new SniffQuoteAndDelimByAdjacency(compact('lineTerminator'));
161		return $sniffer->sniff($data);
162		}
163
164		/**
165		* @todo To make this class more oop and test-friendly, implement strategy pattern here with each delim sniffing method implemented in its own strategy class.
166		*/
167		protected function sniffDelimiter($data, $lineTerminator)
168		{
169		$delimiters = $this->getPossibleDelimiters();
170		$consistency = new SniffDelimiterByConsistency(compact('lineTerminator', 'delimiters'));
171		$winners = $consistency->sniff($data);
172		if (count($winners) > 1) {
173		$delimiters = $winners;
174		return (new SniffDelimiterByDistribution(compact('lineTerminator', 'delimiters')))
175		->sniff($data);
176		}
177		return current($winners);
178		}
179
180		protected function sniffQuotingStyle($delimiter, $eols)
		0 ignored issues – show Unused Code introduced 2018-07-14 08:04 UTC by Report Bug Copy Issue Report The parameter `$delimiter` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history... Unused Code introduced 2018-07-14 08:04 UTC by Report Bug Copy Issue Report The parameter `$eols` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
181		{
182		return Dialect::QUOTE_MINIMAL;
183		}
184
185		protected function sniffHeader($delimiter, $eols)
		0 ignored issues – show Unused Code introduced 2018-07-14 08:04 UTC by Report Bug Copy Issue Report The parameter `$delimiter` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history... Unused Code introduced 2018-07-14 08:04 UTC by Report Bug Copy Issue Report The parameter `$eols` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
186		{
187		return true;
188		}
189		}
190

nozavroni / csvelte

Pull Request — master (#183)

Sniffer::setPossibleDelimiters() A

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