From 54f2e0f419e28db1f1c3d73ae41a6d06dce21b69 Mon Sep 17 00:00:00 2001
From: Tomas Votruba <tomas.vot@gmail.com>
Date: Sun, 12 Jul 2026 13:04:11 +0200
Subject: [PATCH] [CodeQuality] Skip union types in AssertEqualsToSameRector to
 preserve loose type comparison

---
 .../Fixture/skip_union_type.php.inc            | 18 ++++++++++++++++++
 .../MethodCall/AssertEqualsToSameRector.php    |  6 ++++++
 2 files changed, 24 insertions(+)
 create mode 100644 rules-tests/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector/Fixture/skip_union_type.php.inc

diff --git a/rules-tests/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector/Fixture/skip_union_type.php.inc b/rules-tests/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector/Fixture/skip_union_type.php.inc
new file mode 100644
index 00000000..588281c4
--- /dev/null
+++ b/rules-tests/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector/Fixture/skip_union_type.php.inc
@@ -0,0 +1,18 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\MethodCall\AssertEqualsToSameRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SkipUnionType extends TestCase
+{
+    public function test(string|int|bool|\DateTime $expected)
+    {
+        $this->assertEquals('value', $this->normalizeStringValue($expected));
+    }
+
+    private function normalizeStringValue(string|int|bool|\DateTime $input): string|int|bool|\DateTime
+    {
+        return $input;
+    }
+}
diff --git a/rules/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector.php b/rules/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector.php
index 34239f45..256b70dd 100644
--- a/rules/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector.php
+++ b/rules/CodeQuality/Rector/MethodCall/AssertEqualsToSameRector.php
@@ -23,6 +23,7 @@
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
+use PHPStan\Type\UnionType;
 use Rector\PHPUnit\NodeAnalyzer\IdentifierManipulator;
 use Rector\PHPUnit\NodeAnalyzer\TestsNodeAnalyzer;
 use Rector\Rector\AbstractRector;
@@ -126,6 +127,11 @@ private function shouldSkipLooseComparison(array $args): bool
         $firstArgType = $this->nodeTypeResolver->getNativeType($args[0]->value);
         $secondArgType = TypeCombinator::removeNull($this->nodeTypeResolver->getNativeType($args[1]->value));
 
+        // union type can hold different types that assertEquals() compares loosely, keep it safe
+        if ($secondArgType instanceof UnionType) {
+            return true;
+        }
+
         // loose comparison
         if ($firstArgType instanceof IntegerType && ($secondArgType instanceof FloatType || $secondArgType instanceof StringType)) {
             return true;