[DeadCode] Skip used in next For_/Foreach_ on RemoveDeadIfForeachForR…

…ector (#5154)

* [DeadCode] Skip used in next For_/Foreach_ on RemoveDeadIfForeachForRector

* [DeadCode] Skip used in next For_/Foreach_ on RemoveDeadIfForeachForRector

rules-tests/DeadCode/Rector/For_/RemoveDeadIfForeachForRector/Fixture/skip_used_in_next_stmt.php.inc

@@ -0,0 +1,19 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\For_\RemoveDeadIfForeachForRector\Fixture;
+
+class SkipUsedInNextStmt
+{
+    public function run($resultLen, $result, $decimalSep)
+    {
+        for ($i = $resultLen - 1; $i >= 0 && $result[$i] === '0'; $i--) {
+            ;
+        }
+
+        if ($i >= 0 && $result[$i] === $decimalSep) {
+          $i--;
+        }
+
+        $result = substr($result, 0, $i + 1);
+    }
+}

rules-tests/DeadCode/Rector/For_/RemoveDeadIfForeachForRector/Fixture/skip_used_in_next_stmt2.php.inc

@@ -0,0 +1,19 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\For_\RemoveDeadIfForeachForRector\Fixture;
+
+class SkipUsedInNextStmt2
+{
+    public function run($resultLen, $result, $decimalSep)
+    {
+        foreach ($result as $i => $value) {
+            ;
+        }
+
+        if ($i >= 0 && $result[$i] === $decimalSep) {
+          $i--;
+        }
+
+        $result = substr($result, 0, $i + 1);
+    }
+}

rules/DeadCode/Rector/For_/RemoveDeadIfForeachForRector.php

@@ -8,11 +8,13 @@
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\CallLike;
+use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\Stmt\Else_;
 use PhpParser\Node\Stmt\For_;
 use PhpParser\Node\Stmt\Foreach_;
 use PhpParser\Node\Stmt\If_;
-use PhpParser\NodeTraverser;
+use Rector\Core\Contract\PhpParser\Node\StmtsAwareInterface;
+use Rector\Core\NodeManipulator\StmtsManipulator;
 use Rector\Core\PhpParser\Node\BetterNodeFinder;
 use Rector\Core\Rector\AbstractRector;
 use Rector\EarlyReturn\NodeTransformer\ConditionInverter;
@@ -24,9 +26,12 @@
  */
 final class RemoveDeadIfForeachForRector extends AbstractRector
 {
+    private bool $hasChanged = false;
+
     public function __construct(
         private readonly ConditionInverter $conditionInverter,
-        private readonly BetterNodeFinder $betterNodeFinder
+        private readonly BetterNodeFinder $betterNodeFinder,
+        private readonly StmtsManipulator $stmtsManipulator
     ) {
     }
 
@@ -71,45 +76,104 @@ public function run($value)
      */
     public function getNodeTypes(): array
     {
-        return [For_::class, If_::class, Foreach_::class];
+        return [StmtsAwareInterface::class];
     }
 
     /**
-     * @param For_|If_|Foreach_ $node
+     * @param StmtsAwareInterface $node
      */
     public function refactor(Node $node): Node|null|int
     {
-        if ($node instanceof If_) {
-            if ($node->stmts !== []) {
-                return null;
-            }
+        if ($node->stmts === null) {
+            return null;
+        }
 
-            if ($node->elseifs !== []) {
-                return null;
+        $this->hasChanged = false;
+        foreach ($node->stmts as $key => $stmt) {
+            if (! $stmt instanceof If_ && ! $stmt instanceof For_ && ! $stmt instanceof Foreach_) {
+                continue;
             }
 
-            // useless if ()
-            if (! $node->else instanceof Else_) {
-                if ($this->hasNodeSideEffect($node->cond)) {
-                    return null;
-                }
+            if ($stmt->stmts !== []) {
+                continue;
+            }
 
-                return NodeTraverser::REMOVE_NODE;
+            if ($stmt instanceof If_) {
+                $this->processIf($stmt, $key, $node);
+                continue;
             }
 
-            $node->cond = $this->conditionInverter->createInvertedCondition($node->cond);
-            $node->stmts = $node->else->stmts;
-            $node->else = null;
+            $this->processForForeach($stmt, $key, $node);
+        }
 
+        if ($this->hasChanged) {
             return $node;
         }
 
-        // nothing to "for"
-        if ($node->stmts === []) {
-            return NodeTraverser::REMOVE_NODE;
+        return null;
+    }
+
+    private function processIf(If_ $if, int $key, StmtsAwareInterface $stmtsAware): void
+    {
+        if ($if->elseifs !== []) {
+            return;
         }
 
-        return null;
+        // useless if ()
+        if (! $if->else instanceof Else_) {
+            if ($this->hasNodeSideEffect($if->cond)) {
+                return;
+            }
+
+            unset($stmtsAware->stmts[$key]);
+            $this->hasChanged = true;
+            return;
+        }
+
+        $if->cond = $this->conditionInverter->createInvertedCondition($if->cond);
+        $if->stmts = $if->else->stmts;
+        $if->else = null;
+
+        $this->hasChanged = true;
+    }
+
+    private function processForForeach(For_|Foreach_ $for, int $key, StmtsAwareInterface $stmtsAware): void
+    {
+        if ($for instanceof For_) {
+            $variables = $this->betterNodeFinder->findInstanceOf(
+                [...$for->init, ...$for->cond, ...$for->loop],
+                Variable::class
+            );
+            foreach ($variables as $variable) {
+                if ($this->stmtsManipulator->isVariableUsedInNextStmt(
+                    $stmtsAware,
+                    $key + 1,
+                    (string) $this->getName($variable)
+                )) {
+                    return;
+                }
+            }
+
+            unset($stmtsAware->stmts[$key]);
+            $this->hasChanged = true;
+
+            return;
+        }
+
+        $exprs = array_filter([$for->expr, $for->valueVar, $for->valueVar]);
+        $variables = $this->betterNodeFinder->findInstanceOf($exprs, Variable::class);
+        foreach ($variables as $variable) {
+            if ($this->stmtsManipulator->isVariableUsedInNextStmt(
+                $stmtsAware,
+                $key + 1,
+                (string) $this->getName($variable)
+            )) {
+                return;
+            }
+        }
+
+        unset($stmtsAware->stmts[$key]);
+        $this->hasChanged = true;
     }
 
     private function hasNodeSideEffect(Expr $expr): bool