class CyclomaticComplexitySniff

class CyclomaticComplexitySniff implements Sniff {
    
    /**
     * A complexity higher than this value will throw a warning.
     *
     * @var integer
     */
    public $complexity = 10;
    
    /**
     * A complexity higher than this value will throw an error.
     *
     * @var integer
     */
    public $absoluteComplexity = 20;
    
    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_FUNCTION,
        ];
    }
    
    //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 void
     */
    public function process(File $phpcsFile, $stackPtr) {
        $tokens = $phpcsFile->getTokens();
        // Ignore abstract methods.
        if (isset($tokens[$stackPtr]['scope_opener']) === false) {
            return;
        }
        // Detect start and end of this function definition.
        $start = $tokens[$stackPtr]['scope_opener'];
        $end = $tokens[$stackPtr]['scope_closer'];
        // Predicate nodes for PHP.
        $find = [
            T_CASE => true,
            T_DEFAULT => true,
            T_CATCH => true,
            T_IF => true,
            T_FOR => true,
            T_FOREACH => true,
            T_WHILE => true,
            T_ELSEIF => true,
            T_INLINE_THEN => true,
            T_COALESCE => true,
            T_COALESCE_EQUAL => true,
            T_MATCH_ARROW => true,
            T_NULLSAFE_OBJECT_OPERATOR => true,
        ];
        $complexity = 1;
        // Iterate from start to end and count predicate nodes.
        for ($i = $start + 1; $i < $end; $i++) {
            if (isset($find[$tokens[$i]['code']]) === true) {
                $complexity++;
            }
        }
        if ($complexity > $this->absoluteComplexity) {
            $error = 'Function\'s cyclomatic complexity (%s) exceeds allowed maximum of %s';
            $data = [
                $complexity,
                $this->absoluteComplexity,
            ];
            $phpcsFile->addError($error, $stackPtr, 'MaxExceeded', $data);
        }
        else {
            if ($complexity > $this->complexity) {
                $warning = 'Function\'s cyclomatic complexity (%s) exceeds %s; consider refactoring the function';
                $data = [
                    $complexity,
                    $this->complexity,
                ];
                $phpcsFile->addWarning($warning, $stackPtr, 'TooHigh', $data);
            }
        }
    }
    
    //end process()

}