class AssignmentInConditionSniff

class AssignmentInConditionSniff implements Sniff {
    
    /**
     * Assignment tokens to trigger on.
     *
     * Set in the register() method.
     *
     * @var array
     */
    protected $assignmentTokens = [];
    
    /**
     * The tokens that indicate the start of a condition.
     *
     * @var array
     */
    protected $conditionStartTokens = [];
    
    /**
     * Registers the tokens that this sniff wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        $this->assignmentTokens = Tokens::$assignmentTokens;
        unset($this->assignmentTokens[T_DOUBLE_ARROW]);
        $starters = Tokens::$booleanOperators;
        $starters[T_SEMICOLON] = T_SEMICOLON;
        $starters[T_OPEN_PARENTHESIS] = T_OPEN_PARENTHESIS;
        $this->conditionStartTokens = $starters;
        return [
            T_IF,
            T_ELSEIF,
            T_FOR,
            T_SWITCH,
            T_CASE,
            T_WHILE,
            T_MATCH,
        ];
    }
    
    //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();
        $token = $tokens[$stackPtr];
        // Find the condition opener/closer.
        if ($token['code'] === T_FOR) {
            if (isset($token['parenthesis_opener'], $token['parenthesis_closer']) === false) {
                return;
            }
            $semicolon = $phpcsFile->findNext(T_SEMICOLON, $token['parenthesis_opener'] + 1, $token['parenthesis_closer']);
            if ($semicolon === false) {
                return;
            }
            $opener = $semicolon;
            $semicolon = $phpcsFile->findNext(T_SEMICOLON, $opener + 1, $token['parenthesis_closer']);
            if ($semicolon === false) {
                return;
            }
            $closer = $semicolon;
            unset($semicolon);
        }
        else {
            if ($token['code'] === T_CASE) {
                if (isset($token['scope_opener']) === false) {
                    return;
                }
                $opener = $stackPtr;
                $closer = $token['scope_opener'];
            }
            else {
                if (isset($token['parenthesis_opener'], $token['parenthesis_closer']) === false) {
                    return;
                }
                $opener = $token['parenthesis_opener'];
                $closer = $token['parenthesis_closer'];
            }
        }
        
        //end if
        $startPos = $opener;
        do {
            $hasAssignment = $phpcsFile->findNext($this->assignmentTokens, $startPos + 1, $closer);
            if ($hasAssignment === false) {
                return;
            }
            // Examine whether the left side is a variable.
            $hasVariable = false;
            $conditionStart = $startPos;
            $altConditionStart = $phpcsFile->findPrevious($this->conditionStartTokens, $hasAssignment - 1, $startPos);
            if ($altConditionStart !== false) {
                $conditionStart = $altConditionStart;
            }
            for ($i = $hasAssignment; $i > $conditionStart; $i--) {
                if (isset(Tokens::$emptyTokens[$tokens[$i]['code']]) === true) {
                    continue;
                }
                // If this is a variable or array, we've seen all we need to see.
                if ($tokens[$i]['code'] === T_VARIABLE || $tokens[$i]['code'] === T_CLOSE_SQUARE_BRACKET) {
                    $hasVariable = true;
                    break;
                }
                // If this is a function call or something, we are OK.
                if ($tokens[$i]['code'] === T_CLOSE_PARENTHESIS) {
                    break;
                }
            }
            if ($hasVariable === true) {
                $errorCode = 'Found';
                if ($token['code'] === T_WHILE) {
                    $errorCode = 'FoundInWhileCondition';
                }
                $phpcsFile->addWarning('Variable assignment found within a condition. Did you mean to do a comparison ?', $hasAssignment, $errorCode);
            }
            $startPos = $hasAssignment;
        } while ($startPos < $closer);
    }
    
    //end process()

}