minor #569 Forbid declare strict types (OskarStark)

This PR was squashed before being merged into the main branch.

Discussion
----------

 Forbid declare strict types

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Docs?         | no
| Issues        | --
| License       | MIT

Commits
-------

fe9ce13  Forbid declare strict types

Author: OskarStark

.phpstan/ForbidDeclareStrictTypesRule.php

@@ -0,0 +1,62 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\PHPStan;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\Declare_;
+use PhpParser\Node\Stmt\DeclareDeclare;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * PHPStan rule that forbids usage of declare(strict_types=1) statements.
+ *
+ * This rule enforces that strict_types declaration should not be used.
+ *
+ * @author Oskar Stark <[email protected]>
+ *
+ * @implements Rule<Declare_>
+ */
+final class ForbidDeclareStrictTypesRule implements Rule
+{
+    public function getNodeType(): string
+    {
+        return Declare_::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        if (!$node instanceof Declare_) {
+            return [];
+        }
+
+        $errors = [];
+
+        foreach ($node->declares as $declare) {
+            if ($declare instanceof DeclareDeclare) {
+                $key = $declare->key->toString();
+                if ('strict_types' === $key) {
+                    $errors[] = RuleErrorBuilder::message(
+                        'Usage of declare(strict_types=1) is forbidden. Remove the declare statement.'
+                    )
+                    ->line($node->getLine())
+                    ->identifier('symfonyAi.forbidDeclareStrictTypes')
+                    ->tip('Remove the declare(strict_types=1) statement from the file.')
+                    ->build();
+                }
+            }
+        }
+
+        return $errors;
+    }
+}

.phpstan/extension.neon

@@ -1,2 +1,3 @@
 rules:
+    - Symfony\AI\PHPStan\ForbidDeclareStrictTypesRule
     - Symfony\AI\PHPStan\ForbidNativeExceptionRule