PHPCodeValidator.php

<?php

namespace CleantalkSP\Common\Scanner\HeuristicAnalyser\Modules;

class PHPCodeValidator
{
    /**
     * The result of checks
     *
     * @var array
     */
    public $check_list_result;

    /**
     * The tokens to be validated.
     *
     * @var Tokens
     */
    private $tokens;

    /**
     * PHPCodeValidator constructor.
     *
     * @param Tokens $tokens The tokens to be validated.
     */
    public function __construct($tokens)
    {
        $this->tokens = $tokens;
    }

    /**
     * Checks if the PHP code is valid.
     *
     * @return bool Returns true if the PHP code is valid, false otherwise.
     * @psalm-suppress PossiblyUnusedMethod
     */
    public function isValidPHPCode()
    {
        $this->hasCorrectPHPOpenTags();
        $this->checkBraces();
        $this->checkBrackets();
        $this->checkParentheses();
        $this->checkSingleQuotes();
        $this->checkDoubleQuotes();
        $this->checkDigitsStartedVariables();
        return empty($this->check_list_result);
    }

    /**
     * Checks if the count of left and right braces and brackets are equal.
     *
     * @return bool Returns true if the count is equal, false otherwise.
     */
    private function checkBraces()
    {
        $braces_l_count = 0;
        $braces_r_count = 0;

        foreach ( $this->tokens as $token ) {
            if ( $token[0] === '__SERV' ) {
                if ( $token[1] === '(' ) {
                    $braces_l_count++;
                }
                if ( $token[1] === ')' ) {
                    $braces_r_count++;
                }
            }
        }

        if ( $braces_l_count !== $braces_r_count ) {
            $this->check_list_result[__FUNCTION__] = 'Braces () count is not equal ' . $braces_l_count . ' != ' . $braces_r_count;
            return false;
        }

        return true;
    }

    /**
     * Checks if the count of left and right brackets are equal.
     *
     * @return bool Returns true if the count is equal, false otherwise.
     */
    private function checkBrackets()
    {
        $brackets_l_count = 0;
        $brackets_r_count = 0;

        foreach ( $this->tokens as $token ) {
            if ( $token[0] === '__SERV' ) {
                if ( $token[1] === '[' ) {
                    $brackets_l_count++;
                }
                if ( $token[1] === ']' ) {
                    $brackets_r_count++;
                }
            }
        }

        if ( $brackets_l_count !== $brackets_r_count ) {
            $this->check_list_result[__FUNCTION__] = 'Brackets [] count is not equal';
            return false;
        }

        return true;
    }

    /**
     * Checks if the count of left and right parentheses are equal.
     *
     * @return bool Returns true if the count is equal, false otherwise.
     */
    private function checkParentheses()
    {
        $parentheses_l_count = 0;
        $parentheses_r_count = 0;

        /**
         * init opening and closing tokens, key is token type, value is string to search
         */
        $opening_tokens = array(
            '__SERV' => '{',
            'T_CURLY_OPEN' => '{',
            'T_DOLLAR_OPEN_CURLY_BRACES' => '${',
            'T_STRING_VARNAME' => '{'
        );

        $closing_tokens = array(
            '__SERV' => '}',
            'T_STRING_VARNAME' => '}'
        );

        foreach ( $this->tokens as $token ) {
            if ( isset($opening_tokens[$token[0]]) &&
                $token[1] === $opening_tokens[$token[0]] ) {
                $parentheses_l_count++;
            }
            if ( isset($closing_tokens[$token[0]]) &&
                $token[1] === $closing_tokens[$token[0]] ) {
                $parentheses_r_count++;
            }
        }

        if ( $parentheses_l_count !== $parentheses_r_count ) {
            $this->check_list_result[__FUNCTION__] = 'Parentheses {} count is not equal';
            return false;
        }

        return true;
    }

    /**
     * Checks if the count of single quotes are even.
     *
     * @return bool Returns true if the count is even, false otherwise.
     */
    private function checkSingleQuotes()
    {
        $single_quotes_count = 0;

        foreach ( $this->tokens as $token ) {
            if ( $token[0] === '__SERV' ) {
                if ( $token[1] === "'" ) {
                    $single_quotes_count++;
                }
            }
        }

        if ( $single_quotes_count % 2 !== 0 ) {
            $this->check_list_result[__FUNCTION__] = 'Single quotes count is not even';
            return false;
        }
        return true;
    }

    /**
     * Checks if the count of double quotes are even.
     *
     * @return bool Returns true if the count is even, false otherwise.
     */
    private function checkDoubleQuotes()
    {
        $double_quotes_count = 0;

        foreach ( $this->tokens as $token ) {
            if ( $token[0] === '__SERV' ) {
                if ( $token[1] === '"' ) {
                    $double_quotes_count++;
                }
            }
        }

        if ( $double_quotes_count % 2 !== 0 ) {
            $this->check_list_result[__FUNCTION__] = 'Double quotes count is not even';
            return false;
        }
        return true;
    }

    /**
     * Checks if variables contain digits.
     *
     * @return bool Returns true if no variables contain digits, false otherwise.
     */
    private function checkDigitsStartedVariables()
    {
        foreach ( $this->tokens as $token ) {
            if ( $token[0] === 'T_VARIABLE' ) {
                if ( preg_match('/^\$\d.+/', $token[1]) ) {
                    $this->check_list_result[__FUNCTION__] = 'Variable starts with digits [' . $token[1] . ']';
                    return false;
                }
            }
        }
        return true;
    }

    /**
     * Checks if the file does not contain PHP open tags ("<\?php" or `<\?`).
     *
     * @return bool Returns true if the file does not contain PHP open tags, false otherwise.
     */
    public function hasCorrectPHPOpenTags()
    {
        foreach ( $this->tokens as $_token => $content ) {
            if ( isset($content[0]) && isset($this->tokens->next1[0]) ) {
                if ( $content[0] === 'T_OPEN_TAG' ) {
                    //check if open tag is short
                    $is_short = isset($content[1]) && $content[1] === '<?';
                    if ( $is_short ) {
                        if ( $this->tokens->next1[0] !== 'T_WHITESPACE' ) {
                            $this->check_list_result[__FUNCTION__] = 'PHP open tags are not valid';
                            return false;
                        }
                    } else {
                        return true;
                    }
                }
            }
        }

        return false;
    }
}