Chris@16: <?php
Chris@16: 
Chris@16: /*
Chris@16:  * This file is part of Psy Shell.
Chris@16:  *
Chris@16:  * (c) 2012-2018 Justin Hileman
Chris@16:  *
Chris@16:  * For the full copyright and license information, please view the LICENSE
Chris@16:  * file that was distributed with this source code.
Chris@16:  */
Chris@16: 
Chris@16: namespace Psy\CodeCleaner;
Chris@16: 
Chris@16: use PhpParser\Node;
Chris@17: use PhpParser\Node\Expr;
Chris@16: use PhpParser\Node\Expr\Array_;
Chris@17: use PhpParser\Node\Expr\ArrayDimFetch;
Chris@16: use PhpParser\Node\Expr\ArrayItem;
Chris@16: use PhpParser\Node\Expr\Assign;
Chris@17: use PhpParser\Node\Expr\FuncCall;
Chris@16: use PhpParser\Node\Expr\List_;
Chris@17: use PhpParser\Node\Expr\MethodCall;
Chris@17: use PhpParser\Node\Expr\PropertyFetch;
Chris@16: use PhpParser\Node\Expr\Variable;
Chris@16: use Psy\Exception\ParseErrorException;
Chris@16: 
Chris@16: /**
Chris@16:  * Validate that the list assignment.
Chris@16:  */
Chris@16: class ListPass extends CodeCleanerPass
Chris@16: {
Chris@16:     private $atLeastPhp71;
Chris@16: 
Chris@16:     public function __construct()
Chris@16:     {
Chris@17:         $this->atLeastPhp71 = \version_compare(PHP_VERSION, '7.1', '>=');
Chris@16:     }
Chris@16: 
Chris@16:     /**
Chris@16:      * Validate use of list assignment.
Chris@16:      *
Chris@16:      * @throws ParseErrorException if the user used empty with anything but a variable
Chris@16:      *
Chris@16:      * @param Node $node
Chris@16:      */
Chris@16:     public function enterNode(Node $node)
Chris@16:     {
Chris@16:         if (!$node instanceof Assign) {
Chris@16:             return;
Chris@16:         }
Chris@16: 
Chris@16:         if (!$node->var instanceof Array_ && !$node->var instanceof List_) {
Chris@16:             return;
Chris@16:         }
Chris@16: 
Chris@16:         if (!$this->atLeastPhp71 && $node->var instanceof Array_) {
Chris@16:             $msg = "syntax error, unexpected '='";
Chris@16:             throw new ParseErrorException($msg, $node->expr->getLine());
Chris@16:         }
Chris@16: 
Chris@16:         // Polyfill for PHP-Parser 2.x
Chris@16:         $items = isset($node->var->items) ? $node->var->items : $node->var->vars;
Chris@16: 
Chris@16:         if ($items === [] || $items === [null]) {
Chris@16:             throw new ParseErrorException('Cannot use empty list', $node->var->getLine());
Chris@16:         }
Chris@16: 
Chris@16:         $itemFound = false;
Chris@16:         foreach ($items as $item) {
Chris@16:             if ($item === null) {
Chris@16:                 continue;
Chris@16:             }
Chris@16: 
Chris@16:             $itemFound = true;
Chris@16: 
Chris@16:             // List_->$vars in PHP-Parser 2.x is Variable instead of ArrayItem.
Chris@16:             if (!$this->atLeastPhp71 && $item instanceof ArrayItem && $item->key !== null) {
Chris@16:                 $msg = 'Syntax error, unexpected T_CONSTANT_ENCAPSED_STRING, expecting \',\' or \')\'';
Chris@16:                 throw new ParseErrorException($msg, $item->key->getLine());
Chris@16:             }
Chris@16: 
Chris@17:             if (!self::isValidArrayItem($item)) {
Chris@16:                 $msg = 'Assignments can only happen to writable values';
Chris@16:                 throw new ParseErrorException($msg, $item->getLine());
Chris@16:             }
Chris@16:         }
Chris@16: 
Chris@16:         if (!$itemFound) {
Chris@16:             throw new ParseErrorException('Cannot use empty list');
Chris@16:         }
Chris@16:     }
Chris@17: 
Chris@17:     /**
Chris@17:      * Validate whether a given item in an array is valid for short assignment.
Chris@17:      *
Chris@17:      * @param Expr $item
Chris@17:      *
Chris@17:      * @return bool
Chris@17:      */
Chris@17:     private static function isValidArrayItem(Expr $item)
Chris@17:     {
Chris@17:         $value = ($item instanceof ArrayItem) ? $item->value : $item;
Chris@17: 
Chris@17:         while ($value instanceof ArrayDimFetch || $value instanceof PropertyFetch) {
Chris@17:             $value = $value->var;
Chris@17:         }
Chris@17: 
Chris@17:         // We just kind of give up if it's a method call. We can't tell if it's
Chris@17:         // valid via static analysis.
Chris@17:         return $value instanceof Variable || $value instanceof MethodCall || $value instanceof FuncCall;
Chris@17:     }
Chris@16: }