fix with known offset

rules-tests/DeadCode/Rector/If_/RemoveUnusedNonEmptyArrayBeforeForeachRector/Fixture/offset_exists_dim_fetch.php.inc

@@ -0,0 +1,59 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\If_\RemoveUnusedNonEmptyArrayBeforeForeachRector\Fixture;
+
+class KnownOffset
+{
+    public const DEFAULT_GROUP = 'default';
+
+    /**
+     * @var array<string, list<self>>
+     */
+    private static $groups = [];
+
+    public static function knownOffset(): array
+    {
+        $group = 'default';
+
+        self::$groups[$group] = ["foo"];
+
+        if (! empty(self::$groups[$group])) {
+            foreach (self::$groups[$group] as $group) {
+                echo "hello";
+            }
+        }
+
+        return [];
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\If_\RemoveUnusedNonEmptyArrayBeforeForeachRector\Fixture;
+
+class KnownOffset
+{
+    public const DEFAULT_GROUP = 'default';
+
+    /**
+     * @var array<string, list<self>>
+     */
+    private static $groups = [];
+
+    public static function knownOffset(): array
+    {
+        $group = 'default';
+
+        self::$groups[$group] = ["foo"];
+
+        foreach (self::$groups[$group] as $group) {
+            echo "hello";
+        }
+
+        return [];
+    }
+}
+
+?>

rules/DeadCode/Rector/If_/RemoveUnusedNonEmptyArrayBeforeForeachRector.php

@@ -106,8 +106,12 @@ private function isUselessBeforeForeachCheck(If_ $if, Scope $scope): bool
         $foreach = $if->stmts[0];
         $foreachExpr = $foreach->expr;
 
-        if ($foreachExpr instanceof Expr\ArrayDimFetch) {
-            return false;
+        if ($foreachExpr instanceof Expr\ArrayDimFetch && $foreachExpr->dim !== null) {
+            $exprType = $this->nodeTypeResolver->getNativeType($foreachExpr->var);
+            $dimType = $this->nodeTypeResolver->getNativeType($foreachExpr->dim);
+            if (!$exprType->hasOffsetValueType($dimType)->yes()) {
+                return false;
+            }
         }
 
         if ($foreachExpr instanceof Variable) {