class BrowserSpecificStylesSniff

class BrowserSpecificStylesSniff implements Sniff {
    
    /**
     * A list of tokenizers this sniff supports.
     *
     * @var array
     */
    public $supportedTokenizers = [
        'CSS',
    ];
    
    /**
     * A list of specific stylesheet suffixes we allow.
     *
     * These stylesheets contain browser specific styles
     * so this sniff ignore them files in the form:
     * *_moz.css and *_ie7.css etc.
     *
     * @var array
     */
    protected $specificStylesheets = [
        'moz' => true,
        'ie' => true,
        'ie7' => true,
        'ie8' => true,
        'webkit' => true,
    ];
    
    /**
     * Returns the token types that this sniff is interested in.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_STYLE,
        ];
    }
    
    //end register()
    
    /**
     * Processes the tokens that this sniff is interested in.
     *
     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file where the token was found.
     * @param int                         $stackPtr  The position in the stack where
     *                                               the token was found.
     *
     * @return void
     */
    public function process(File $phpcsFile, $stackPtr) {
        // Ignore files with browser-specific suffixes.
        $filename = $phpcsFile->getFilename();
        $breakChar = strrpos($filename, '_');
        if ($breakChar !== false && substr($filename, -4) === '.css') {
            $specific = substr($filename, $breakChar + 1, -4);
            if (isset($this->specificStylesheets[$specific]) === true) {
                return;
            }
        }
        $tokens = $phpcsFile->getTokens();
        $content = $tokens[$stackPtr]['content'];
        if ($content[0] === '-') {
            $error = 'Browser-specific styles are not allowed';
            $phpcsFile->addError($error, $stackPtr, 'ForbiddenStyle');
        }
    }
    
    //end process()

}