DisallowMultipleAssignmentsSniff.php

<?php


/**
 * Ensures there is only one assignment on a line, and that it is the first thing on the line.
 *
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @copyright 2006-2015 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
 */
namespace PHP_CodeSniffer\Standards\Squiz\Sniffs\PHP;

use PHP_CodeSniffer\Files\File;
use PHP_CodeSniffer\Sniffs\Sniff;
use PHP_CodeSniffer\Util\Tokens;
class DisallowMultipleAssignmentsSniff implements Sniff {
    
    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_EQUAL,
        ];
    }
    
    //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 default value assignments in function definitions.
        $function = $phpcsFile->findPrevious([
            T_FUNCTION,
            T_CLOSURE,
            T_FN,
        ], $stackPtr - 1, null, false, null, true);
        if ($function !== false) {
            if (isset($tokens[$function]['parenthesis_closer']) === false) {
                // Live coding/parse error. Bow out.
                return;
            }
            $opener = $tokens[$function]['parenthesis_opener'];
            $closer = $tokens[$function]['parenthesis_closer'];
            if ($opener < $stackPtr && $closer > $stackPtr) {
                return;
            }
        }
        // Ignore assignments in WHILE loop conditions.
        if (isset($tokens[$stackPtr]['nested_parenthesis']) === true) {
            $nested = $tokens[$stackPtr]['nested_parenthesis'];
            foreach ($nested as $opener => $closer) {
                if (isset($tokens[$opener]['parenthesis_owner']) === true && $tokens[$tokens[$opener]['parenthesis_owner']]['code'] === T_WHILE) {
                    return;
                }
            }
        }
        // Ignore member var definitions.
        if (empty($tokens[$stackPtr]['conditions']) === false) {
            $conditions = $tokens[$stackPtr]['conditions'];
            end($conditions);
            $deepestScope = key($conditions);
            if (isset(Tokens::$ooScopeTokens[$tokens[$deepestScope]['code']]) === true) {
                return;
            }
        }
        
        /*
            The general rule is:
            Find an equal sign and go backwards along the line. If you hit an
            end bracket, skip to the opening bracket. When you find a variable,
            stop. That variable must be the first non-empty token on the line
            or in the statement. If not, throw an error.
        */
        for ($varToken = $stackPtr - 1; $varToken >= 0; $varToken--) {
            if (in_array($tokens[$varToken]['code'], [
                T_SEMICOLON,
                T_OPEN_CURLY_BRACKET,
                T_CLOSE_TAG,
            ], true) === true) {
                // We've reached the previous statement, so we didn't find a variable.
                return;
            }
            // Skip brackets.
            if (isset($tokens[$varToken]['parenthesis_opener']) === true && $tokens[$varToken]['parenthesis_opener'] < $varToken) {
                $varToken = $tokens[$varToken]['parenthesis_opener'];
                continue;
            }
            if (isset($tokens[$varToken]['bracket_opener']) === true) {
                $varToken = $tokens[$varToken]['bracket_opener'];
                continue;
            }
            if ($tokens[$varToken]['code'] === T_VARIABLE) {
                $prevNonEmpty = $phpcsFile->findPrevious(Tokens::$emptyTokens, $varToken - 1, null, true);
                if ($tokens[$prevNonEmpty]['code'] === T_OBJECT_OPERATOR) {
                    // Dynamic property access, the real "start" variable still needs to be found.
                    $varToken = $prevNonEmpty;
                    continue;
                }
                // We found our variable.
                break;
            }
        }
        
        //end for
        if ($varToken <= 0) {
            // Didn't find a variable.
            return;
        }
        $start = $phpcsFile->findStartOfStatement($varToken);
        $allowed = Tokens::$emptyTokens;
        $allowed[T_STRING] = T_STRING;
        $allowed[T_NS_SEPARATOR] = T_NS_SEPARATOR;
        $allowed[T_DOUBLE_COLON] = T_DOUBLE_COLON;
        $allowed[T_ASPERAND] = T_ASPERAND;
        $allowed[T_DOLLAR] = T_DOLLAR;
        $allowed[T_SELF] = T_SELF;
        $allowed[T_PARENT] = T_PARENT;
        $allowed[T_STATIC] = T_STATIC;
        $varToken = $phpcsFile->findPrevious($allowed, $varToken - 1, null, true);
        if ($varToken < $start && $tokens[$varToken]['code'] !== T_OPEN_PARENTHESIS && $tokens[$varToken]['code'] !== T_OPEN_SQUARE_BRACKET) {
            $varToken = $start;
        }
        // Ignore the first part of FOR loops as we are allowed to
        // assign variables there even though the variable is not the
        // first thing on the line.
        if ($tokens[$varToken]['code'] === T_OPEN_PARENTHESIS && isset($tokens[$varToken]['parenthesis_owner']) === true) {
            $owner = $tokens[$varToken]['parenthesis_owner'];
            if ($tokens[$owner]['code'] === T_FOR) {
                return;
            }
        }
        if ($tokens[$varToken]['code'] === T_VARIABLE || $tokens[$varToken]['code'] === T_OPEN_TAG || $tokens[$varToken]['code'] === T_GOTO_LABEL || $tokens[$varToken]['code'] === T_INLINE_THEN || $tokens[$varToken]['code'] === T_INLINE_ELSE || $tokens[$varToken]['code'] === T_SEMICOLON || $tokens[$varToken]['code'] === T_CLOSE_PARENTHESIS || isset($allowed[$tokens[$varToken]['code']]) === true) {
            return;
        }
        $error = 'Assignments must be the first block of code on a line';
        $errorCode = 'Found';
        if (isset($nested) === true) {
            $controlStructures = [
                T_IF => T_IF,
                T_ELSEIF => T_ELSEIF,
                T_SWITCH => T_SWITCH,
                T_CASE => T_CASE,
                T_FOR => T_FOR,
                T_MATCH => T_MATCH,
            ];
            foreach ($nested as $opener => $closer) {
                if (isset($tokens[$opener]['parenthesis_owner']) === true && isset($controlStructures[$tokens[$tokens[$opener]['parenthesis_owner']]['code']]) === true) {
                    $errorCode .= 'InControlStructure';
                    break;
                }
            }
        }
        $phpcsFile->addError($error, $stackPtr, $errorCode);
    }
    
    //end process()

}

//end class