[DowngradePhp74] Do not remove non-null default value on nullable on …

…DowngradeTypedPropertyRector (#1687)

rules-tests/DowngradePhp74/Rector/Property/DowngradeTypedPropertyRector/Fixture/nullable_type_with_default_not_null.php.inc

@@ -0,0 +1,24 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp74\Rector\Property\DowngradeTypedPropertyRector\Fixture;
+
+class NullableTypeWithDefaultNotNull
+{
+    protected ?string $test = "test";
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp74\Rector\Property\DowngradeTypedPropertyRector\Fixture;
+
+class NullableTypeWithDefaultNotNull
+{
+    /**
+     * @var string|null
+     */
+    protected $test = "test";
+}
+
+?>

rules/DowngradePhp74/Rector/Property/DowngradeTypedPropertyRector.php

@@ -6,6 +6,7 @@
 
 use PhpParser\Node;
 use PhpParser\Node\ComplexType;
+use PhpParser\Node\Expr;
 use PhpParser\Node\Identifier;
 use PhpParser\Node\Name;
 use PhpParser\Node\NullableType;
@@ -66,7 +67,8 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
-        if ($node->type instanceof NullableType) {
+        $default = $node->props[0]->default;
+        if ($node->type instanceof NullableType && $default instanceof Expr && $this->valueResolver->isNull($default)) {
             $node->props[0]->default = null;
         }