PHP_CodeSniffer, PHPMD or PHP Depend

PHP offers several powerful code analysis tools to help maintain code quality and enforce coding standards. Three essential tools − PHP_CodeSniffer (phpcs), PHPMD, and PHP Depend (pdepend) − each serve different purposes in code quality assessment.

PHP_CodeSniffer (phpcs)

PHP_CodeSniffer tokenizes PHP, JavaScript, and CSS files to detect violations against predefined coding standards. It ensures code consistency and helps prevent common semantic errors.

Installation: Install via Composer: composer global require "squizlabs/php_codesniffer=*"

Example Usage

Here's how to check a PHP file against PSR−12 coding standard ?

<?php
// sample.php - File with coding standard violations
class myClass{
public function getData( $param ){
if($param==null)return false;
$result=$this->process($param);
return $result;
}
}
?>

Command to run PHP_CodeSniffer ?

phpcs --standard=PSR12 sample.php

FILE: sample.php
FOUND 5 ERRORS AFFECTING 4 LINES
 2 | ERROR | Class name "myClass" is not in PascalCase format
 3 | ERROR | Expected 0 spaces after opening parenthesis; 1 found
 4 | ERROR | Expected 1 space after IF keyword; 0 found
 4 | ERROR | Expected 1 space before closing parenthesis; 0 found

PHPMD (PHP Mess Detector)

PHPMD scans PHP source code to identify potential problems including possible bugs, suboptimal code, and overcomplicated expressions.

Installation: Install via Composer: composer global require phpmd/phpmd

Example Usage

Sample PHP code with potential issues ?

<?php
class UserManager {
    public function processUserData($userData) {
        // Unused variable
        $tempData = array();
        
        // Overly complex condition
        if (isset($userData['name']) && !empty($userData['name']) && 
            isset($userData['email']) && !empty($userData['email']) &&
            isset($userData['age']) && is_numeric($userData['age']) &&
            $userData['age'] > 0 && $userData['age'] < 120) {
            return true;
        }
        return false;
    }
}
?>

Command to run PHPMD ?

phpmd UserManager.php text cleancode,unusedcode

UserManager.php:5    Avoid unused local variables such as '$tempData'.
UserManager.php:7    The method processUserData() has a Cyclomatic Complexity of 4.

PHP Depend (pdepend)

PHP Depend generates comprehensive software metrics from codebases to measure project quality and identify areas requiring refactoring.

Installation: Install via Composer: composer global require pdepend/pdepend

Example Usage

Command to generate dependency analysis ?

pdepend --jdepend-xml=report.xml --overview-pyramid=pyramid.svg /path/to/source

Sample metrics output ?

Analyzing Dependencies...
Classes: 25
Methods: 127
Lines of Code: 2,341
Cyclomatic Complexity: 8.5
Maintainability Index: 85.3

Comparison

Conclusion

These three tools complement each other perfectly − use PHP_CodeSniffer for coding standards, PHPMD for code quality issues, and PHP Depend for architectural insights and metrics.