class FileExtensionSniff

class FileExtensionSniff implements Sniff {
    
    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_OPEN_TAG,
        ];
    }
    
    //end register()
    
    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being scanned.
     * @param int                         $stackPtr  The position of the current token in the
     *                                               stack passed in $tokens.
     *
     * @return int
     */
    public function process(File $phpcsFile, $stackPtr) {
        $tokens = $phpcsFile->getTokens();
        $fileName = $phpcsFile->getFilename();
        $extension = substr($fileName, strrpos($fileName, '.'));
        $nextClass = $phpcsFile->findNext([
            T_CLASS,
            T_INTERFACE,
            T_TRAIT,
            T_ENUM,
        ], $stackPtr);
        if ($nextClass !== false) {
            $phpcsFile->recordMetric($stackPtr, 'File extension for class files', $extension);
            if ($extension === '.php') {
                $error = '%s found in ".php" file; use ".inc" extension instead';
                $data = [
                    ucfirst($tokens[$nextClass]['content']),
                ];
                $phpcsFile->addError($error, $stackPtr, 'ClassFound', $data);
            }
        }
        else {
            $phpcsFile->recordMetric($stackPtr, 'File extension for non-class files', $extension);
            if ($extension === '.inc') {
                $error = 'No interface or class found in ".inc" file; use ".php" extension instead';
                $phpcsFile->addError($error, $stackPtr, 'NoClass');
            }
        }
        // Ignore the rest of the file.
        return $phpcsFile->numTokens;
    }
    
    //end process()

}