skip as array key

Author: samsonasik

rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_key.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipAsArrayKey
+{
+    public function run()
+    {
+         $data = [
+            substr('a', 2) => 'foo'
+        ];
+
+        var_dump($data);
+    }
+}

rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php

@@ -6,6 +6,7 @@
 
 use PhpParser\Node;
 use PhpParser\Node\Arg;
+use PhpParser\Node\ArrayItem;
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\AssignOp;
 use PhpParser\Node\Expr\BinaryOp\Concat;
@@ -77,12 +78,13 @@ public function getNodeTypes(): array
             If_::class,
             While_::class,
             Do_::class,
+            ArrayItem::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|ArrayItem|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -122,6 +124,14 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof ArrayItem) {
+            if ($node->key instanceof Expr) {
+                $node->key->setAttribute(self::IS_UNCASTABLE, true);
+            }
+
+            return null;
+        }
+
         if ($node instanceof CallLike) {
             if ($node->isFirstClassCallable()) {
                 return null;