<?php
/*
* This file is part of Psy Shell.
*
* (c) 2012-2020 Justin Hileman
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Psy\CodeCleaner;
use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\Array_;
use PhpParser\Node\Expr\ArrayDimFetch;
use PhpParser\Node\Expr\ArrayItem;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\FuncCall;
use PhpParser\Node\Expr\List_;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\PropertyFetch;
use PhpParser\Node\Expr\Variable;
use Psy\Exception\ParseErrorException;
/**
* Validate that the list assignment.
*/
class ListPass extends CodeCleanerPass
{
private $atLeastPhp71;
public function __construct()
{
$this->atLeastPhp71 = \version_compare(PHP_VERSION, '7.1', '>=');
}
/**
* Validate use of list assignment.
*
* @throws ParseErrorException if the user used empty with anything but a variable
*
* @param Node $node
*/
public function enterNode(Node $node)
{
if (!$node instanceof Assign) {
return;
}
if (!$node->var instanceof Array_ && !$node->var instanceof List_) {
return;
}
if (!$this->atLeastPhp71 && $node->var instanceof Array_) {
$msg = "syntax error, unexpected '='";
throw new ParseErrorException($msg, $node->expr->getLine());
}
// Polyfill for PHP-Parser 2.x
$items = isset($node->var->items) ? $node->var->items : $node->var->vars;
if ($items === [] || $items === [null]) {
throw new ParseErrorException('Cannot use empty list', $node->var->getLine());
}
$itemFound = false;
foreach ($items as $item) {
if ($item === null) {
continue;
}
$itemFound = true;
// List_->$vars in PHP-Parser 2.x is Variable instead of ArrayItem.
if (!$this->atLeastPhp71 && $item instanceof ArrayItem && $item->key !== null) {
$msg = 'Syntax error, unexpected T_CONSTANT_ENCAPSED_STRING, expecting \',\' or \')\'';
throw new ParseErrorException($msg, $item->key->getLine());
}
if (!self::isValidArrayItem($item)) {
$msg = 'Assignments can only happen to writable values';
throw new ParseErrorException($msg, $item->getLine());
}
}
if (!$itemFound) {
throw new ParseErrorException('Cannot use empty list');
}
}
/**
* Validate whether a given item in an array is valid for short assignment.
*
* @param Expr $item
*
* @return bool
*/
private static function isValidArrayItem(Expr $item)
{
$value = ($item instanceof ArrayItem) ? $item->value : $item;
while ($value instanceof ArrayDimFetch || $value instanceof PropertyFetch) {
$value = $value->var;
}
// We just kind of give up if it's a method call. We can't tell if it's
// valid via static analysis.
return $value instanceof Variable || $value instanceof MethodCall || $value instanceof FuncCall;
}
}