rector/rules/php72/src/Rector/FuncCall/CreateFunctionToAnonymousFunctionRector.php

<?php

declare(strict_types=1);

namespace Rector\Php72\Rector\FuncCall;

use PhpParser\Node;
use PhpParser\Node\Arg;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\BinaryOp\Concat;
use PhpParser\Node\Expr\Closure;
use PhpParser\Node\Expr\FuncCall;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Name;
use PhpParser\Node\Param;
use PhpParser\Node\Scalar\Encapsed;
use PhpParser\Node\Scalar\String_;
use PhpParser\Node\Stmt;
use PhpParser\Node\Stmt\Expression;
use Rector\Core\Exception\ShouldNotHappenException;
use Rector\Core\Php\ReservedKeywordAnalyzer;
use Rector\Core\PhpParser\Parser\InlineCodeParser;
use Rector\Core\Rector\AbstractRector;
use Rector\Php72\NodeFactory\AnonymousFunctionFactory;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see https://stackoverflow.com/q/48161526/1348344
 * @see http://php.net/manual/en/migration72.deprecated.php#migration72.deprecated.create_function-function
 *
 * @see \Rector\Php72\Tests\Rector\FuncCall\CreateFunctionToAnonymousFunctionRector\CreateFunctionToAnonymousFunctionRectorTest
 */
final class CreateFunctionToAnonymousFunctionRector extends AbstractRector
{
    /**
     * @var InlineCodeParser
     */
    private $inlineCodeParser;

    /**
     * @var AnonymousFunctionFactory
     */
    private $anonymousFunctionFactory;

    /**
     * @var ReservedKeywordAnalyzer
     */
    private $reservedKeywordAnalyzer;

    public function __construct(
        InlineCodeParser $inlineCodeParser,
        AnonymousFunctionFactory $anonymousFunctionFactory,
        ReservedKeywordAnalyzer $reservedKeywordAnalyzer
    ) {
        $this->inlineCodeParser = $inlineCodeParser;
        $this->anonymousFunctionFactory = $anonymousFunctionFactory;
        $this->reservedKeywordAnalyzer = $reservedKeywordAnalyzer;
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition(
            'Use anonymous functions instead of deprecated create_function()',
            [
                new CodeSample(
                    <<<'CODE_SAMPLE'
class ClassWithCreateFunction
{
    public function run()
    {
        $callable = create_function('$matches', "return '$delimiter' . strtolower(\$matches[1]);");
    }
}
CODE_SAMPLE
                    ,
                    <<<'CODE_SAMPLE'
class ClassWithCreateFunction
{
    public function run()
    {
        $callable = function($matches) use ($delimiter) {
            return $delimiter . strtolower($matches[1]);
        };
    }
}
CODE_SAMPLE
            ),
            ]);
    }

    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes(): array
    {
        return [FuncCall::class];
    }

    /**
     * @param FuncCall $node
     * @return Closure|null
     */
    public function refactor(Node $node): ?Node
    {
        if (! $this->isName($node, 'create_function')) {
            return null;
        }

        $params = $this->createParamsFromString($node->args[0]->value);
        $stmts = $this->parseStringToBody($node->args[1]->value);

        $refactored = $this->anonymousFunctionFactory->create($params, $stmts, null);
        foreach ($refactored->uses as $key => $use) {
            if (! $use->var instanceof Variable) {
                continue;
            }

            $variableName = $this->getName($use->var);
            if ($variableName === null) {
                continue;
            }

            if ($this->reservedKeywordAnalyzer->isNativeVariable($variableName)) {
                unset($refactored->uses[$key]);
            }
        }

        return $refactored;
    }

    /**
     * @return Param[]
     */
    private function createParamsFromString(Expr $expr): array
    {
        $content = $this->inlineCodeParser->stringify($expr);
        $content = '<?php $value = function(' . $content . ') {};';

        $nodes = $this->inlineCodeParser->parse($content);

        /** @var Expression $expression */
        $expression = $nodes[0];

        /** @var Assign $assign */
        $assign = $expression->expr;

        /** @var Closure $function */
        $function = $assign->expr;
        if (! $function instanceof Closure) {
            throw new ShouldNotHappenException();
        }

        return $function->params;
    }

    /**
     * @return Expression[]|Stmt[]
     */
    private function parseStringToBody(Expr $expr): array
    {
        if (! $expr instanceof String_ && ! $expr instanceof Encapsed && ! $expr instanceof Concat) {
            // special case of code elsewhere
            return [$this->createEval($expr)];
        }

        $expr = $this->inlineCodeParser->stringify($expr);
        return $this->inlineCodeParser->parse($expr);
    }

    private function createEval(Expr $expr): Expression
    {
        $evalFuncCall = new FuncCall(new Name('eval'), [new Arg($expr)]);
        return new Expression($evalFuncCall);
    }
}