From 13c02b805eebb869c759e790d9cbbb3e36276a21 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:00:28 +0700
Subject: [PATCH 01/29] [DowngradePhp80] Add DowngradeSubstrFalsyRector

---
 config/set/downgrade-php80.php                |  2 +
 .../DowngradeSubstrFalsyRectorTest.php        | 28 +++++++
 .../Fixture/by_variable_string.php.inc        | 27 +++++++
 .../Fixture/fixture.php.inc                   | 27 +++++++
 .../Fixture/skip_already_casted.php.inc       | 11 +++
 .../Fixture/skip_different_func_call.php.inc  | 11 +++
 .../Fixture/skip_empty.php.inc                | 14 ++++
 .../Fixture/skip_never_empty.php.inc          | 11 +++
 .../Fixture/skip_ternary_falsy.php.inc        | 11 +++
 .../config/configured_rule.php                | 10 +++
 .../FuncCall/DowngradeSubstrFalsyRector.php   | 74 +++++++++++++++++++
 11 files changed, 226 insertions(+)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/DowngradeSubstrFalsyRectorTest.php
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/by_variable_string.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/fixture.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_already_casted.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_different_func_call.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_empty.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_never_empty.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_ternary_falsy.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/config/configured_rule.php
 create mode 100644 rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php

diff --git a/config/set/downgrade-php80.php b/config/set/downgrade-php80.php
index ce89592e..9e13c73c 100644
--- a/config/set/downgrade-php80.php
+++ b/config/set/downgrade-php80.php
@@ -23,6 +23,7 @@
 use Rector\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsRector;
 use Rector\DowngradePhp80\Rector\FuncCall\DowngradeStrEndsWithRector;
 use Rector\DowngradePhp80\Rector\FuncCall\DowngradeStrStartsWithRector;
+use Rector\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector;
 use Rector\DowngradePhp80\Rector\FunctionLike\DowngradeMixedTypeDeclarationRector;
 use Rector\DowngradePhp80\Rector\FunctionLike\DowngradeUnionTypeDeclarationRector;
 use Rector\DowngradePhp80\Rector\Instanceof_\DowngradeInstanceofStringableRector;
@@ -91,5 +92,6 @@
         RemoveReturnTypeDeclarationFromCloneRector::class,
         DowngradeEnumToConstantListClassRector::class,
         DowngradeInstanceofStringableRector::class,
+        DowngradeSubstrFalsyRector::class,
     ]);
 };
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/DowngradeSubstrFalsyRectorTest.php b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/DowngradeSubstrFalsyRectorTest.php
new file mode 100644
index 00000000..e7f4d292
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/DowngradeSubstrFalsyRectorTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class DowngradeSubstrFalsyRectorTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/by_variable_string.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/by_variable_string.php.inc
new file mode 100644
index 00000000..464b3fc6
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/by_variable_string.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class ByVariableString
+{
+    public function run(string $name)
+    {
+        return substr($name, 2);
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class ByVariableString
+{
+    public function run(string $name)
+    {
+        return (string) substr($name, 2);
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/fixture.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/fixture.php.inc
new file mode 100644
index 00000000..ea7b6685
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/fixture.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class Fixture
+{
+    public function run()
+    {
+        return substr("a", 2);
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class Fixture
+{
+    public function run()
+    {
+        return (string) substr("a", 2);
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_already_casted.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_already_casted.php.inc
new file mode 100644
index 00000000..bd271390
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_already_casted.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipAlreadyCasted
+{
+    public function run()
+    {
+        return (string) substr("a", 2);
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_different_func_call.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_different_func_call.php.inc
new file mode 100644
index 00000000..449c45f2
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_different_func_call.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipDifferentFuncCall
+{
+    public function run()
+    {
+        return strlen('a');
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_empty.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_empty.php.inc
new file mode 100644
index 00000000..9c8b0476
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_empty.php.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * empty can be false or empty string ""
+ */
+class SkipEmpty
+{
+    public function run()
+    {
+        return empty(substr("a", 2));
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_never_empty.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_never_empty.php.inc
new file mode 100644
index 00000000..b9936e86
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_never_empty.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipNeverEmpty
+{
+    public function run()
+    {
+        return substr("abc", 2);
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_ternary_falsy.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_ternary_falsy.php.inc
new file mode 100644
index 00000000..c0bffd12
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_ternary_falsy.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipTernaryFalsy
+{
+    public function run()
+    {
+        return substr('a', 2) ?: 'default';
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/config/configured_rule.php b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/config/configured_rule.php
new file mode 100644
index 00000000..1f861b32
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/config/configured_rule.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(DowngradeSubstrFalsyRector::class);
+};
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
new file mode 100644
index 00000000..0487b3bd
--- /dev/null
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DowngradePhp80\Rector\FuncCall;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Cast\String_;
+use PhpParser\Node\Expr\Empty_;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\Ternary;
+use Rector\Rector\AbstractRector;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @changelog https://php.watch/versions/8.0/substr-out-of-bounds
+ *
+ * @see \Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\DowngradeSubstrFalsyRectorTest
+ */
+final class DowngradeSubstrFalsyRector extends AbstractRector
+{
+    /**
+     * @var string
+     */
+    private const IS_UNCASTABLE = 'is_uncastable';
+
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition('Downgrade substr() with cast string on possibly falsy result', [
+            new CodeSample('substr("a", 2);', '(string) substr("a", 2);'),
+        ]);
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [String_::class, Empty_::class, Ternary::class, FuncCall::class];
+    }
+
+    /**
+     * @param String_|Empty_|Ternary|FuncCall $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if ($node instanceof String_ || $node instanceof Empty_) {
+            $node->expr->setAttribute(self::IS_UNCASTABLE, true);
+            return null;
+        }
+
+        if ($node instanceof Ternary && ! $node->if instanceof Expr) {
+            $node->cond->setAttribute(self::IS_UNCASTABLE, true);
+            return null;
+        }
+
+        if (! $this->isName($node, 'substr')) {
+            return null;
+        }
+
+        if ($node->getAttribute(self::IS_UNCASTABLE) === true) {
+            return null;
+        }
+
+        $type = $this->getType($node);
+        if ($type->isNonEmptyString()->yes()) {
+            return null;
+        }
+
+        return new String_($node);
+    }
+}

From 6d51910793e911fe742d62b839eb95fa29d06ed7 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:02:16 +0700
Subject: [PATCH 02/29] [DowngradePhp80] Add DowngradeSubstrFalsyRector

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php         | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 0487b3bd..0882f9c8 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -51,8 +51,11 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
-        if ($node instanceof Ternary && ! $node->if instanceof Expr) {
-            $node->cond->setAttribute(self::IS_UNCASTABLE, true);
+        if ($node instanceof Ternary) {
+            if ($node->if instanceof Expr) {
+                $node->cond->setAttribute(self::IS_UNCASTABLE, true);
+            }
+
             return null;
         }
 

From 12d80c8575e84a12400b6787f63dae1e6186bede Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:02:55 +0700
Subject: [PATCH 03/29] [DowngradePhp80] Add DowngradeSubstrFalsyRector

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php              | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 0882f9c8..8559df87 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -52,7 +52,7 @@ public function refactor(Node $node): ?Node
         }
 
         if ($node instanceof Ternary) {
-            if ($node->if instanceof Expr) {
+            if (! $node->if instanceof Expr) {
                 $node->cond->setAttribute(self::IS_UNCASTABLE, true);
             }
 

From edb3a4f488885fcd93105d62d12edaa55e27fd2e Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:04:21 +0700
Subject: [PATCH 04/29] [DowngradePhp80] Add DowngradeSubstrFalsyRector

---
 tests/Issues/DowngradeHeredoc/Fixture/next_arg.php.inc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/Issues/DowngradeHeredoc/Fixture/next_arg.php.inc b/tests/Issues/DowngradeHeredoc/Fixture/next_arg.php.inc
index 1f117df8..db204c12 100644
--- a/tests/Issues/DowngradeHeredoc/Fixture/next_arg.php.inc
+++ b/tests/Issues/DowngradeHeredoc/Fixture/next_arg.php.inc
@@ -474,9 +474,9 @@ final class NextArg
         $lineString = trim($lineString);
 
         if (strncmp($lineString, '/**', strlen('/**')) === 0) {
-            $lineString = substr($lineString, 3);
+            $lineString = (string) substr($lineString, 3);
         } elseif (strncmp($lineString, '*', strlen('*')) === 0) {
-            $lineString = substr($lineString, 1);
+            $lineString = (string) substr($lineString, 1);
         }
 
         return trim($lineString);

From d9635109bc95ef4296083a7d205523939f9e749d Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:11:44 +0700
Subject: [PATCH 05/29] skip negated

---
 .../Fixture/skip_negated.php.inc                   | 14 ++++++++++++++
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php |  7 ++++---
 2 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negated.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negated.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negated.php.inc
new file mode 100644
index 00000000..ed83c522
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negated.php.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * negation can be false or empty string ""
+ */
+class SkipNegated
+{
+    public function run()
+    {
+        return ! substr('a', 2);
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 8559df87..1ea04a9e 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -6,6 +6,7 @@
 
 use PhpParser\Node;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\BooleanNot;
 use PhpParser\Node\Expr\Cast\String_;
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
@@ -38,15 +39,15 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [String_::class, Empty_::class, Ternary::class, FuncCall::class];
+        return [String_::class, Empty_::class, BooleanNot::class, Ternary::class, FuncCall::class];
     }
 
     /**
-     * @param String_|Empty_|Ternary|FuncCall $node
+     * @param String_|Empty_|BooleanNot|Ternary|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
-        if ($node instanceof String_ || $node instanceof Empty_) {
+        if ($node instanceof String_ || $node instanceof Empty_ || $node instanceof BooleanNot) {
             $node->expr->setAttribute(self::IS_UNCASTABLE, true);
             return null;
         }

From e5b2a2ee753437ab3aba3830d649686b699f70c0 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:14:16 +0700
Subject: [PATCH 06/29] skip casted bool

---
 .../Fixture/skip_casted_bool.php.inc                  | 11 +++++++++++
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php    |  7 ++++---
 2 files changed, 15 insertions(+), 3 deletions(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_casted_bool.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_casted_bool.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_casted_bool.php.inc
new file mode 100644
index 00000000..f78c7eeb
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_casted_bool.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipCastedBool
+{
+    public function run(string $name)
+    {
+        return (bool) substr($name, 2);
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 1ea04a9e..11139b39 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -7,6 +7,7 @@
 use PhpParser\Node;
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\BooleanNot;
+use PhpParser\Node\Expr\Cast;
 use PhpParser\Node\Expr\Cast\String_;
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
@@ -39,15 +40,15 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [String_::class, Empty_::class, BooleanNot::class, Ternary::class, FuncCall::class];
+        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, FuncCall::class];
     }
 
     /**
-     * @param String_|Empty_|BooleanNot|Ternary|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
-        if ($node instanceof String_ || $node instanceof Empty_ || $node instanceof BooleanNot) {
+        if ($node instanceof Cast || $node instanceof Empty_ || $node instanceof BooleanNot) {
             $node->expr->setAttribute(self::IS_UNCASTABLE, true);
             return null;
         }

From 121104e0fe36a3899fedf4aa3fc399a1af49f65c Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:25:00 +0700
Subject: [PATCH 07/29] skip compared to false

---
 .../Fixture/skip_compared_to_false.php.inc    | 12 +++++++++
 .../FuncCall/DowngradeSubstrFalsyRector.php   | 25 +++++++++++++++++--
 2 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc
new file mode 100644
index 00000000..8d51b460
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc
@@ -0,0 +1,12 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipComparedToFalse
+{
+    public function run(string $name)
+    {
+        substr($name, 2) == false;
+        substr($name, 2) === false;
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 11139b39..528b418e 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -6,12 +6,15 @@
 
 use PhpParser\Node;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\BinaryOp\Equal;
+use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
 use PhpParser\Node\Expr\Cast;
 use PhpParser\Node\Expr\Cast\String_;
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\Ternary;
+use Rector\PhpParser\Node\Value\ValueResolver;
 use Rector\Rector\AbstractRector;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
@@ -28,6 +31,12 @@ final class DowngradeSubstrFalsyRector extends AbstractRector
      */
     private const IS_UNCASTABLE = 'is_uncastable';
 
+    public function __construct(
+        private readonly ValueResolver $valueResolver
+    ) {
+
+    }
+
     public function getRuleDefinition(): RuleDefinition
     {
         return new RuleDefinition('Downgrade substr() with cast string on possibly falsy result', [
@@ -40,11 +49,11 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, FuncCall::class];
+        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, Equal::class, Identical::class, FuncCall::class];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Equal|Identical|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -61,6 +70,18 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof Equal || $node instanceof Identical) {
+            if ($this->valueResolver->isFalse($node->left)) {
+                $node->right->setAttribute(self::IS_UNCASTABLE, true);
+            }
+
+            if ($this->valueResolver->isFalse($node->right)) {
+                $node->left->setAttribute(self::IS_UNCASTABLE, true);
+            }
+
+            return null;
+        }
+
         if (! $this->isName($node, 'substr')) {
             return null;
         }

From 15357353e65f3d2697b3353abedadfdeeedca2e7 Mon Sep 17 00:00:00 2001
From: GitHub Action <actions@github.com>
Date: Mon, 13 Oct 2025 14:25:49 +0000
Subject: [PATCH 08/29] [ci-review] Rector Rectify

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php     | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 528b418e..7bf78ed1 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -49,7 +49,15 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, Equal::class, Identical::class, FuncCall::class];
+        return [
+            Cast::class,
+            Empty_::class,
+            BooleanNot::class,
+            Ternary::class,
+            Equal::class,
+            Identical::class,
+            FuncCall::class,
+        ];
     }
 
     /**

From d653bba71a3c81766e589dc3a94ccf4595ef1335 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:26:15 +0700
Subject: [PATCH 09/29] skip compared to false

---
 .../Fixture/skip_compared_to_false.php.inc        |  1 -
 .../FuncCall/DowngradeSubstrFalsyRector.php       | 15 +++------------
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc
index 8d51b460..619faa6a 100644
--- a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_compared_to_false.php.inc
@@ -6,7 +6,6 @@ class SkipComparedToFalse
 {
     public function run(string $name)
     {
-        substr($name, 2) == false;
         substr($name, 2) === false;
     }
 }
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 7bf78ed1..5829e14c 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -6,7 +6,6 @@
 
 use PhpParser\Node;
 use PhpParser\Node\Expr;
-use PhpParser\Node\Expr\BinaryOp\Equal;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
 use PhpParser\Node\Expr\Cast;
@@ -49,19 +48,11 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [
-            Cast::class,
-            Empty_::class,
-            BooleanNot::class,
-            Ternary::class,
-            Equal::class,
-            Identical::class,
-            FuncCall::class,
-        ];
+        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, Identical::class, FuncCall::class];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Equal|Identical|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -78,7 +69,7 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
-        if ($node instanceof Equal || $node instanceof Identical) {
+        if ($node instanceof Identical) {
             if ($this->valueResolver->isFalse($node->left)) {
                 $node->right->setAttribute(self::IS_UNCASTABLE, true);
             }

From e0d8b56bdb7808e29e597e46687db71c8cf0eb1a Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:45:03 +0700
Subject: [PATCH 10/29] skip zero offset

---
 .../skip_zero_offset_with_no_length.php.inc   | 14 ++++++++++++++
 ...p_zero_offset_with_positive_length.php.inc | 14 ++++++++++++++
 .../FuncCall/DowngradeSubstrFalsyRector.php   | 19 +++++++++++++++++++
 3 files changed, 47 insertions(+)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_no_length.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_positive_length.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_no_length.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_no_length.php.inc
new file mode 100644
index 00000000..f05440b4
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_no_length.php.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * zero offset with no length can't be false
+ */
+class SkipZeroOffsetWithNoLength
+{
+    public function run(string $name)
+    {
+        return substr($name, 0);
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_positive_length.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_positive_length.php.inc
new file mode 100644
index 00000000..cfead068
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_zero_offset_with_positive_length.php.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * zero offset with postive length can't be false
+ */
+class SkipZeroOffsetWithPositiveLength
+{
+    public function run(string $name)
+    {
+        return substr($name, 0, 10);
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 5829e14c..e6c63183 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -5,6 +5,7 @@
 namespace Rector\DowngradePhp80\Rector\FuncCall;
 
 use PhpParser\Node;
+use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
@@ -13,6 +14,7 @@
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\Ternary;
+use PHPStan\Type\Constant\ConstantIntegerType;
 use Rector\PhpParser\Node\Value\ValueResolver;
 use Rector\Rector\AbstractRector;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
@@ -94,6 +96,23 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        $offset = $node->getArg('offset', 1);
+
+        if ($offset instanceof Arg) {
+            $offsetType = $this->getType($offset->value);
+            if ($offsetType instanceof ConstantIntegerType && $offsetType->getValue() === 0) {
+                return null;
+            }
+
+            $length = $node->getArg('length', 2);
+            if ($length instanceof Arg) {
+                $lengthType = $this->getType($length->value);
+                if ($lengthType instanceof ConstantIntegerType && $lengthType->getValue() >= 0) {
+                    return null;
+                }
+            }
+        }
+
         return new String_($node);
     }
 }

From 4b37a51f674a921ed7cced1340681bdb298f9942 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:45:29 +0700
Subject: [PATCH 11/29] skip zero offset

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php              | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index e6c63183..249d051d 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -100,7 +100,7 @@ public function refactor(Node $node): ?Node
 
         if ($offset instanceof Arg) {
             $offsetType = $this->getType($offset->value);
-            if ($offsetType instanceof ConstantIntegerType && $offsetType->getValue() === 0) {
+            if ($offsetType instanceof ConstantIntegerType && $offsetType->getValue() <= 0) {
                 return null;
             }
 

From c5feda89f60c45402c1f9251e0b6ac3da014d701 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 21:48:55 +0700
Subject: [PATCH 12/29] skip negative offset

---
 .../Fixture/skip_negative_offset.php.inc           | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negative_offset.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negative_offset.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negative_offset.php.inc
new file mode 100644
index 00000000..9a942831
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_negative_offset.php.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * zero offset with no length can't be false
+ */
+class SkipNegativeOffset
+{
+    public function run(string $name)
+    {
+        return substr($name, -1);
+    }
+}

From f1e8eeaff25e136bf789e787b60d413467ab8062 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 22:08:16 +0700
Subject: [PATCH 13/29] skip with concat

---
 .../Fixture/skip_with_concat.php.inc.inc           | 14 ++++++++++++++
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php | 11 +++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_with_concat.php.inc.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_with_concat.php.inc.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_with_concat.php.inc.inc
new file mode 100644
index 00000000..b7aa24db
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_with_concat.php.inc.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * falsy concat become empty string
+ */
+class SkipWithConcat
+{
+    public function run()
+    {
+        return substr('a', 2) . substr('b', 2);
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 249d051d..b8d6d6e0 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -7,6 +7,7 @@
 use PhpParser\Node;
 use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
 use PhpParser\Node\Expr\Cast;
@@ -50,11 +51,11 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, Identical::class, FuncCall::class];
+        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, Identical::class, Concat::class, FuncCall::class];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -71,6 +72,12 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof Concat) {
+            $node->left->setAttribute(self::IS_UNCASTABLE, true);
+            $node->right->setAttribute(self::IS_UNCASTABLE, true);
+            return null;
+        }
+
         if ($node instanceof Identical) {
             if ($this->valueResolver->isFalse($node->left)) {
                 $node->right->setAttribute(self::IS_UNCASTABLE, true);

From 0569d22c98d646a11607970d0e7f413152b02caa Mon Sep 17 00:00:00 2001
From: GitHub Action <actions@github.com>
Date: Mon, 13 Oct 2025 15:09:09 +0000
Subject: [PATCH 14/29] [ci-review] Rector Rectify

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php     | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index b8d6d6e0..21ac0a92 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -51,7 +51,15 @@ public function getRuleDefinition(): RuleDefinition
      */
     public function getNodeTypes(): array
     {
-        return [Cast::class, Empty_::class, BooleanNot::class, Ternary::class, Identical::class, Concat::class, FuncCall::class];
+        return [
+            Cast::class,
+            Empty_::class,
+            BooleanNot::class,
+            Ternary::class,
+            Identical::class,
+            Concat::class,
+            FuncCall::class,
+        ];
     }
 
     /**

From a3efa295a9b80a503eb54e38b074b41ad68bec95 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 22:23:07 +0700
Subject: [PATCH 15/29] skip allow falsy arg

---
 .../Fixture/skip_as_falsy_arg.php.inc         | 16 ++++++++
 .../FuncCall/DowngradeSubstrFalsyRector.php   | 39 ++++++++++++++++++-
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_falsy_arg.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_falsy_arg.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_falsy_arg.php.inc
new file mode 100644
index 00000000..50c8efb3
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_falsy_arg.php.inc
@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipAsFalsyArg
+{
+    public function run()
+    {
+        return $this->execute(substr('a', 2));
+    }
+
+    private function execute(false|string $value)
+    {
+        return $value;
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 21ac0a92..c658ec15 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -10,14 +10,20 @@
 use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
+use PhpParser\Node\Expr\CallLike;
 use PhpParser\Node\Expr\Cast;
 use PhpParser\Node\Expr\Cast\String_;
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\Ternary;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Reflection\MethodReflection;
 use PHPStan\Type\Constant\ConstantIntegerType;
+use Rector\NodeTypeResolver\PHPStan\ParametersAcceptorSelectorVariantsWrapper;
 use Rector\PhpParser\Node\Value\ValueResolver;
+use Rector\PHPStan\ScopeFetcher;
 use Rector\Rector\AbstractRector;
+use Rector\Reflection\ReflectionResolver;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
 
@@ -34,6 +40,7 @@ final class DowngradeSubstrFalsyRector extends AbstractRector
     private const IS_UNCASTABLE = 'is_uncastable';
 
     public function __construct(
+        private readonly ReflectionResolver $reflectionResolver,
         private readonly ValueResolver $valueResolver
     ) {
 
@@ -58,12 +65,13 @@ public function getNodeTypes(): array
             Ternary::class,
             Identical::class,
             Concat::class,
+            CallLike::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|CallLike|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -98,6 +106,35 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof CallLike) {
+            if ($node->isFirstClassCallable()) {
+                return null;
+            }
+
+            $reflection = $this->reflectionResolver->resolveFunctionLikeReflectionFromCall($node);
+
+            if (! $reflection instanceof MethodReflection && ! $reflection instanceof FunctionReflection) {
+                return null;
+            }
+
+            $parameterAcceptor = ParametersAcceptorSelectorVariantsWrapper::select(
+                $reflection,
+                $node,
+                ScopeFetcher::fetch($node)
+            );
+
+            foreach ($parameterAcceptor->getParameters() as $position => $parameterReflection) {
+                if ($parameterReflection->getType()->isFalse()->no()) {
+                    continue;
+                }
+
+                $arg = $node->getArg($parameterReflection->getName(), $position);
+                if ($arg instanceof Arg) {
+                    $arg->value->setAttribute(self::IS_UNCASTABLE, true);
+                }
+            }
+        }
+
         if (! $this->isName($node, 'substr')) {
             return null;
         }

From 12077fb9ca7128db02aa36bd72ef679a44d2870c Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 13 Oct 2025 22:28:53 +0700
Subject: [PATCH 16/29] use MethodCall and StaticCall as current
 ReflectionResolver can get

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php         | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index c658ec15..53122027 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -15,6 +15,8 @@
 use PhpParser\Node\Expr\Cast\String_;
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Expr\Ternary;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\MethodReflection;
@@ -65,13 +67,14 @@ public function getNodeTypes(): array
             Ternary::class,
             Identical::class,
             Concat::class,
-            CallLike::class,
+            MethodCall::class,
+            StaticCall::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|CallLike|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {

From 6abd0758e8bd2ad8a24ab8f66644c4c7aaa00ded Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Tue, 14 Oct 2025 06:54:26 +0700
Subject: [PATCH 17/29] skip append

---
 .../Fixture/skip_append.php.inc                     | 13 +++++++++++++
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php  |  6 ++++--
 2 files changed, 17 insertions(+), 2 deletions(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_append.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_append.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_append.php.inc
new file mode 100644
index 00000000..bdde85fa
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_append.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipAppend
+{
+    public function run(string $a)
+    {
+        $a .=substr('a', 2);
+
+        return $a;
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 53122027..120a028c 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -7,6 +7,7 @@
 use PhpParser\Node;
 use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\AssignOp;
 use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
@@ -69,16 +70,17 @@ public function getNodeTypes(): array
             Concat::class,
             MethodCall::class,
             StaticCall::class,
+            AssignOp::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
-        if ($node instanceof Cast || $node instanceof Empty_ || $node instanceof BooleanNot) {
+        if ($node instanceof Cast || $node instanceof Empty_ || $node instanceof BooleanNot || $node instanceof AssignOp) {
             $node->expr->setAttribute(self::IS_UNCASTABLE, true);
             return null;
         }

From b76a519d463d57c7e8678185e06444e50d4e25f1 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Wed, 15 Oct 2025 16:45:13 +0700
Subject: [PATCH 18/29] skip direct on if cond

---
 .../Fixture/compared_to_empty_string.php.inc  | 47 +++++++++++++++++++
 .../Fixture/skip_direct_cond.php.inc          | 13 +++++
 .../FuncCall/DowngradeSubstrFalsyRector.php   |  9 +++-
 3 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_direct_cond.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc
new file mode 100644
index 00000000..4bb99d19
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc
@@ -0,0 +1,47 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class ComparedToEmptyString
+{
+    public function run(string $name)
+    {
+        return substr($name, 2) === '';
+    }
+    
+    public function run2(string $name)
+    {
+        return substr($name, 2) !== '';
+    }
+    
+    public function run3(string $name)
+    {
+        return substr($name, 2) == '';
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class ComparedToEmptyString
+{
+    public function run(string $name)
+    {
+        return (string) substr($name, 2) === '';
+    }
+    
+    public function run2(string $name)
+    {
+        return (string) substr($name, 2) !== '';
+    }
+    
+    public function run3(string $name)
+    {
+        return (string) substr($name, 2) == '';
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_direct_cond.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_direct_cond.php.inc
new file mode 100644
index 00000000..a1998c9f
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_direct_cond.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipDirectCond
+{
+    public function run(string $name)
+    {
+        if (substr($name, 2)) {
+            return true;
+        }
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 120a028c..27f85033 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -19,6 +19,7 @@
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Expr\Ternary;
+use PhpParser\Node\Stmt\If_;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\MethodReflection;
 use PHPStan\Type\Constant\ConstantIntegerType;
@@ -71,12 +72,13 @@ public function getNodeTypes(): array
             MethodCall::class,
             StaticCall::class,
             AssignOp::class,
+            If_::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -111,6 +113,11 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof If_) {
+            $node->cond->setAttribute(self::IS_UNCASTABLE, true);
+            return null;
+        }
+
         if ($node instanceof CallLike) {
             if ($node->isFirstClassCallable()) {
                 return null;

From 0c65912856af1206ecb55107f7744d153b24c946 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Wed, 15 Oct 2025 16:45:55 +0700
Subject: [PATCH 19/29] skip direct on if cond

---
 .../Fixture/compared_to_empty_string.php.inc  | 47 -------------------
 1 file changed, 47 deletions(-)
 delete mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc
deleted file mode 100644
index 4bb99d19..00000000
--- a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/compared_to_empty_string.php.inc
+++ /dev/null
@@ -1,47 +0,0 @@
-<?php
-
-namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
-
-class ComparedToEmptyString
-{
-    public function run(string $name)
-    {
-        return substr($name, 2) === '';
-    }
-    
-    public function run2(string $name)
-    {
-        return substr($name, 2) !== '';
-    }
-    
-    public function run3(string $name)
-    {
-        return substr($name, 2) == '';
-    }
-}
-
-?>
------
-<?php
-
-namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
-
-class ComparedToEmptyString
-{
-    public function run(string $name)
-    {
-        return (string) substr($name, 2) === '';
-    }
-    
-    public function run2(string $name)
-    {
-        return (string) substr($name, 2) !== '';
-    }
-    
-    public function run3(string $name)
-    {
-        return (string) substr($name, 2) == '';
-    }
-}
-
-?>

From 1ca7c16694180a0d2fa69deb1ad29858afcc8444 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Wed, 15 Oct 2025 16:47:00 +0700
Subject: [PATCH 20/29] skip direct on while and do cond

---
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php        | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 27f85033..ca547610 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -19,7 +19,9 @@
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Expr\Ternary;
+use PhpParser\Node\Stmt\Do_;
 use PhpParser\Node\Stmt\If_;
+use PhpParser\Node\Stmt\While_;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\MethodReflection;
 use PHPStan\Type\Constant\ConstantIntegerType;
@@ -73,12 +75,14 @@ public function getNodeTypes(): array
             StaticCall::class,
             AssignOp::class,
             If_::class,
+            While_::class,
+            Do_::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -113,7 +117,7 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
-        if ($node instanceof If_) {
+        if ($node instanceof If_ || $node instanceof While_ || $node instanceof Do_) {
             $node->cond->setAttribute(self::IS_UNCASTABLE, true);
             return null;
         }

From 47562f06ed9a7d4e7e0800b42c3844a6ea0ac0b4 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Wed, 15 Oct 2025 17:25:44 +0700
Subject: [PATCH 21/29] add fixture for skip sprintf arg

---
 .../Fixture/skip_sprintf.php.inc               | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_sprintf.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_sprintf.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_sprintf.php.inc
new file mode 100644
index 00000000..851758d6
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_sprintf.php.inc
@@ -0,0 +1,18 @@
+<?php
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * sprintf %s format converts false to empty string
+ */
+class SkipSprintf
+{
+    public function run(string $name)
+    {
+        return sprintf('Value: %s', substr($name, 2));
+    }
+
+    public function run2(string $name)
+    {
+        printf('Value: %s', substr($name, 2));
+    }
+}
\ No newline at end of file

From 4089265382d435bc14b21056190f701dd2a6e191 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Fri, 17 Oct 2025 11:17:30 +0700
Subject: [PATCH 22/29] skip as array key

---
 .../Fixture/skip_as_array_key.php.inc             | 15 +++++++++++++++
 .../FuncCall/DowngradeSubstrFalsyRector.php       | 12 +++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_key.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_key.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_key.php.inc
new file mode 100644
index 00000000..2e98fcdd
--- /dev/null
+++ b/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);
+    }
+}
\ No newline at end of file
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index ca547610..d1933af8 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/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;

From 7e86548f24186ff66bb645e7cd5728d5726ce15a Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Fri, 17 Oct 2025 11:19:45 +0700
Subject: [PATCH 23/29] skip as array dim fetch dim

---
 .../Fixture/skip_as_array_dim_fetch_dim.php.inc      | 12 ++++++++++++
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php   | 12 +++++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_dim_fetch_dim.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_dim_fetch_dim.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_dim_fetch_dim.php.inc
new file mode 100644
index 00000000..7e2d68fa
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_as_array_dim_fetch_dim.php.inc
@@ -0,0 +1,12 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipAsArrayDimFetchDim
+{
+    public function run()
+    {
+        $data[substr('a', 2)] = 'foo';
+        var_dump($data);
+    }
+}
\ No newline at end of file
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index d1933af8..5ed17a76 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -8,6 +8,7 @@
 use PhpParser\Node\Arg;
 use PhpParser\Node\ArrayItem;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\ArrayDimFetch;
 use PhpParser\Node\Expr\AssignOp;
 use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Expr\BinaryOp\Identical;
@@ -79,12 +80,13 @@ public function getNodeTypes(): array
             While_::class,
             Do_::class,
             ArrayItem::class,
+            ArrayDimFetch::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|ArrayItem|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|ArrayItem|ArrayDimFetch|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -132,6 +134,14 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof ArrayDimFetch) {
+            if ($node->dim instanceof Expr) {
+                $node->dim->setAttribute(self::IS_UNCASTABLE, true);
+            }
+
+            return null;
+        }
+
         if ($node instanceof CallLike) {
             if ($node->isFirstClassCallable()) {
                 return null;

From 0acd09fdfc42e2fbf92e7b81b1c738401151b7a0 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Fri, 17 Oct 2025 12:17:48 +0700
Subject: [PATCH 24/29] skip in binary op

---
 .../Fixture/skip_in_binary_op.php.inc                 | 11 +++++++++++
 .../Rector/FuncCall/DowngradeSubstrFalsyRector.php    | 10 +++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_in_binary_op.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_in_binary_op.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_in_binary_op.php.inc
new file mode 100644
index 00000000..73392e4a
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_in_binary_op.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipInBinaryOp
+{
+    public function run($a)
+    {
+        return substr("a", 2) && $a === true;
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 5ed17a76..608e453b 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -10,6 +10,7 @@
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\ArrayDimFetch;
 use PhpParser\Node\Expr\AssignOp;
+use PhpParser\Node\Expr\BinaryOp;
 use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BooleanNot;
@@ -81,12 +82,13 @@ public function getNodeTypes(): array
             Do_::class,
             ArrayItem::class,
             ArrayDimFetch::class,
+            BinaryOp::class,
             FuncCall::class,
         ];
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|ArrayItem|ArrayDimFetch|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|ArrayItem|ArrayDimFetch|BinaryOp|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {
@@ -142,6 +144,12 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
+        if ($node instanceof BinaryOp) {
+            $node->left->setAttribute(self::IS_UNCASTABLE, true);
+            $node->right->setAttribute(self::IS_UNCASTABLE, true);
+            return null;
+        }
+
         if ($node instanceof CallLike) {
             if ($node->isFirstClassCallable()) {
                 return null;

From 1272b811bd45e4193e2f2fc330601f3a65cd2bd4 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Fri, 17 Oct 2025 13:23:48 +0700
Subject: [PATCH 25/29] skip new arg falsy

---
 .../Fixture/skip_new_arg_falsy.php.inc            | 15 +++++++++++++++
 .../FuncCall/DowngradeSubstrFalsyRector.php       |  4 +++-
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_new_arg_falsy.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_new_arg_falsy.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_new_arg_falsy.php.inc
new file mode 100644
index 00000000..d464729d
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/skip_new_arg_falsy.php.inc
@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+class SkipNewArgFalsy
+{
+    public function __construct(false|string $value)
+    {
+    }
+
+    public function run()
+    {
+        new self(substr('a', 2));
+    }
+}
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index 608e453b..a8644745 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -20,6 +20,7 @@
 use PhpParser\Node\Expr\Empty_;
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Expr\New_;
 use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Expr\Ternary;
 use PhpParser\Node\Stmt\Do_;
@@ -76,6 +77,7 @@ public function getNodeTypes(): array
             Concat::class,
             MethodCall::class,
             StaticCall::class,
+            New_::class,
             AssignOp::class,
             If_::class,
             While_::class,
@@ -88,7 +90,7 @@ public function getNodeTypes(): array
     }
 
     /**
-     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|AssignOp|If_|While_|Do_|ArrayItem|ArrayDimFetch|BinaryOp|FuncCall $node
+     * @param Cast|Empty_|BooleanNot|Ternary|Identical|Concat|MethodCall|StaticCall|New_|AssignOp|If_|While_|Do_|ArrayItem|ArrayDimFetch|BinaryOp|FuncCall $node
      */
     public function refactor(Node $node): ?Node
     {

From 2a1de4cbe208d14ccff5111b2935e19d58dc4721 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 20 Oct 2025 16:58:38 +0700
Subject: [PATCH 26/29] update constant

---
 .../FuncCall/DowngradeSubstrFalsyRector.php   | 28 +++++++++----------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index a8644745..f83b2c19 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -47,7 +47,7 @@ final class DowngradeSubstrFalsyRector extends AbstractRector
     /**
      * @var string
      */
-    private const IS_UNCASTABLE = 'is_uncastable';
+    private const IS_FALSY_UNCASTABLE = 'is_falsy_uncastable';
 
     public function __construct(
         private readonly ReflectionResolver $reflectionResolver,
@@ -95,44 +95,44 @@ public function getNodeTypes(): array
     public function refactor(Node $node): ?Node
     {
         if ($node instanceof Cast || $node instanceof Empty_ || $node instanceof BooleanNot || $node instanceof AssignOp) {
-            $node->expr->setAttribute(self::IS_UNCASTABLE, true);
+            $node->expr->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             return null;
         }
 
         if ($node instanceof Ternary) {
             if (! $node->if instanceof Expr) {
-                $node->cond->setAttribute(self::IS_UNCASTABLE, true);
+                $node->cond->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             }
 
             return null;
         }
 
         if ($node instanceof Concat) {
-            $node->left->setAttribute(self::IS_UNCASTABLE, true);
-            $node->right->setAttribute(self::IS_UNCASTABLE, true);
+            $node->left->setAttribute(self::IS_FALSY_UNCASTABLE, true);
+            $node->right->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             return null;
         }
 
         if ($node instanceof Identical) {
             if ($this->valueResolver->isFalse($node->left)) {
-                $node->right->setAttribute(self::IS_UNCASTABLE, true);
+                $node->right->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             }
 
             if ($this->valueResolver->isFalse($node->right)) {
-                $node->left->setAttribute(self::IS_UNCASTABLE, true);
+                $node->left->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             }
 
             return null;
         }
 
         if ($node instanceof If_ || $node instanceof While_ || $node instanceof Do_) {
-            $node->cond->setAttribute(self::IS_UNCASTABLE, true);
+            $node->cond->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             return null;
         }
 
         if ($node instanceof ArrayItem) {
             if ($node->key instanceof Expr) {
-                $node->key->setAttribute(self::IS_UNCASTABLE, true);
+                $node->key->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             }
 
             return null;
@@ -140,15 +140,15 @@ public function refactor(Node $node): ?Node
 
         if ($node instanceof ArrayDimFetch) {
             if ($node->dim instanceof Expr) {
-                $node->dim->setAttribute(self::IS_UNCASTABLE, true);
+                $node->dim->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             }
 
             return null;
         }
 
         if ($node instanceof BinaryOp) {
-            $node->left->setAttribute(self::IS_UNCASTABLE, true);
-            $node->right->setAttribute(self::IS_UNCASTABLE, true);
+            $node->left->setAttribute(self::IS_FALSY_UNCASTABLE, true);
+            $node->right->setAttribute(self::IS_FALSY_UNCASTABLE, true);
             return null;
         }
 
@@ -176,7 +176,7 @@ public function refactor(Node $node): ?Node
 
                 $arg = $node->getArg($parameterReflection->getName(), $position);
                 if ($arg instanceof Arg) {
-                    $arg->value->setAttribute(self::IS_UNCASTABLE, true);
+                    $arg->value->setAttribute(self::IS_FALSY_UNCASTABLE, true);
                 }
             }
         }
@@ -185,7 +185,7 @@ public function refactor(Node $node): ?Node
             return null;
         }
 
-        if ($node->getAttribute(self::IS_UNCASTABLE) === true) {
+        if ($node->getAttribute(self::IS_FALSY_UNCASTABLE) === true) {
             return null;
         }
 

From 7180a0a4e1f18b739359edccda7f402c2c6f1920 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 20 Oct 2025 17:05:01 +0700
Subject: [PATCH 27/29] add failing fixture zero offset, negative length

---
 .../with_zero_offset_length_negative.php.inc  | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc
new file mode 100644
index 00000000..733607f1
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc
@@ -0,0 +1,33 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * @see https://3v4l.org/lv13M#v7.4.33
+ */
+class WithZeroOffsetLengthNegative
+{
+    public function run(string $name)
+    {
+        return substr($name, 0, -1);
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeSubstrFalsyRector\Fixture;
+
+/**
+ * @see https://3v4l.org/lv13M#v7.4.33
+ */
+class WithZeroOffsetLengthNegative
+{
+    public function run(string $name)
+    {
+        return (string) substr($name, 0, -1);
+    }
+}
+
+?>

From d722c32a0eb06cae06820cc8a26d34eab0d2d717 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 20 Oct 2025 17:05:44 +0700
Subject: [PATCH 28/29] add failing fixture zero offset, negative length

---
 .../Fixture/with_zero_offset_length_negative.php.inc          | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc
index 733607f1..1119a039 100644
--- a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector/Fixture/with_zero_offset_length_negative.php.inc
@@ -9,7 +9,7 @@ class WithZeroOffsetLengthNegative
 {
     public function run(string $name)
     {
-        return substr($name, 0, -1);
+        return substr($name, 0, -5);
     }
 }
 
@@ -26,7 +26,7 @@ class WithZeroOffsetLengthNegative
 {
     public function run(string $name)
     {
-        return (string) substr($name, 0, -1);
+        return (string) substr($name, 0, -5);
     }
 }
 

From 04657b223db16404818d6d9cf0b6d5dd8e23f105 Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Mon, 20 Oct 2025 17:06:43 +0700
Subject: [PATCH 29/29] fix

---
 .../FuncCall/DowngradeSubstrFalsyRector.php    | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
index f83b2c19..9c20aeed 100644
--- a/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeSubstrFalsyRector.php
@@ -199,15 +199,17 @@ public function refactor(Node $node): ?Node
         if ($offset instanceof Arg) {
             $offsetType = $this->getType($offset->value);
             if ($offsetType instanceof ConstantIntegerType && $offsetType->getValue() <= 0) {
-                return null;
-            }
-
-            $length = $node->getArg('length', 2);
-            if ($length instanceof Arg) {
-                $lengthType = $this->getType($length->value);
-                if ($lengthType instanceof ConstantIntegerType && $lengthType->getValue() >= 0) {
-                    return null;
+                $length = $node->getArg('length', 2);
+                if ($length instanceof Arg) {
+                    $lengthType = $this->getType($length->value);
+                    if ($lengthType instanceof ConstantIntegerType && $lengthType->getValue() >= 0) {
+                        return null;
+                    }
+
+                    return new String_($node);
                 }
+
+                return null;
             }
         }