Merge pull request #204 from patchlevel/2.0.x-merge-up-into-2.1.x_AZZUHwqF

Merge release 2.0.1 into 2.1.x

Author: DavidBadura

phpstan-baseline.neon

@@ -192,6 +192,18 @@ parameters:
 			count: 2
 			path: tests/Unit/Normalizer/ArrayNormalizerTest.php
 
+		-
+			message: '#^Call to static method PHPUnit\\Framework\\Assert\:\:assertSame\(\) with array\{1, 2, 3\} and array\{1, 2, 3\} will always evaluate to true\.$#'
+			identifier: staticMethod.alreadyNarrowedType
+			count: 1
+			path: tests/Unit/Normalizer/ArrayNormalizerTest.php
+
+		-
+			message: '#^Call to static method PHPUnit\\Framework\\Assert\:\:assertSame\(\) with array\{101, 102, 103\} and array\{101, 102, 103\} will always evaluate to true\.$#'
+			identifier: staticMethod.alreadyNarrowedType
+			count: 1
+			path: tests/Unit/Normalizer/ArrayNormalizerTest.php
+
 		-
 			message: '#^Cannot cast mixed to int\.$#'
 			identifier: cast.int

src/Normalizer/ArrayNormalizer.php

@@ -35,11 +35,13 @@ public function normalize(mixed $value, array $context): array|null
             throw InvalidArgument::withWrongType('array|null', $value);
         }
 
-        foreach ($value as &$item) {
-            $item = $this->normalizer->normalize($item, $context);
+        $result = [];
+
+        foreach ($value as $key => $item) {
+            $result[$key] = $this->normalizer->normalize($item, $context);
         }
 
-        return $value;
+        return $result;
     }
 
     /**
@@ -57,11 +59,13 @@ public function denormalize(mixed $value, array $context): array|null
             throw InvalidArgument::withWrongType('array|null', $value);
         }
 
-        foreach ($value as &$item) {
-            $item = $this->normalizer->denormalize($item, $context);
+        $result = [];
+
+        foreach ($value as $key => $item) {
+            $result[$key] = $this->normalizer->denormalize($item, $context);
         }
 
-        return $value;
+        return $result;
     }
 
     public function setHydrator(Hydrator $hydrator): void

tests/Unit/Normalizer/ArrayNormalizerTest.php

@@ -4,6 +4,7 @@
 
 namespace Patchlevel\Hydrator\Tests\Unit\Normalizer;
 
+use InvalidArgumentException;
 use Patchlevel\Hydrator\Hydrator;
 use Patchlevel\Hydrator\Normalizer\ArrayNormalizer;
 use Patchlevel\Hydrator\Normalizer\HydratorAwareNormalizer;
@@ -12,6 +13,8 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 
+use function is_int;
+
 #[CoversClass(ArrayNormalizer::class)]
 final class ArrayNormalizerTest extends TestCase
 {
@@ -155,6 +158,83 @@ public function denormalize(mixed $value, array $context = []): mixed
         $this->assertSame([$context, $context], $innerNormalizer->contexts);
     }
 
+    public function testNormalizeDoesNotMutateSourceArrayWithReferencedElement(): void
+    {
+        $innerNormalizer = new class implements Normalizer {
+            /** @param array<string, mixed> $context */
+            public function normalize(mixed $value, array $context): int
+            {
+                if (!is_int($value)) {
+                    throw new InvalidArgumentException();
+                }
+
+                return $value + 100;
+            }
+
+            /** @param array<string, mixed> $context */
+            public function denormalize(mixed $value, array $context): int
+            {
+                if (!is_int($value)) {
+                    throw new InvalidArgumentException();
+                }
+
+                return $value - 100;
+            }
+        };
+
+        $source = [1, 2, 3];
+
+        // A leftover reference from a previous `foreach ($source as &$row)` without
+        // unset() turns the last element into a PHP reference. Iterating the source
+        // by reference inside the normalizer must not write back into it.
+        // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedForeach
+        foreach ($source as &$row) {
+        }
+
+        $normalizer = new ArrayNormalizer($innerNormalizer);
+        $result = $normalizer->normalize($source, []);
+
+        self::assertSame([101, 102, 103], $result);
+        self::assertSame([1, 2, 3], $source);
+    }
+
+    public function testDenormalizeDoesNotMutateSourceArrayWithReferencedElement(): void
+    {
+        $innerNormalizer = new class implements Normalizer {
+            /** @param array<string, mixed> $context */
+            public function normalize(mixed $value, array $context): int
+            {
+                if (!is_int($value)) {
+                    throw new InvalidArgumentException();
+                }
+
+                return $value + 100;
+            }
+
+            /** @param array<string, mixed> $context */
+            public function denormalize(mixed $value, array $context): int
+            {
+                if (!is_int($value)) {
+                    throw new InvalidArgumentException();
+                }
+
+                return $value - 100;
+            }
+        };
+
+        $source = [101, 102, 103];
+
+        // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedForeach
+        foreach ($source as &$row) {
+        }
+
+        $normalizer = new ArrayNormalizer($innerNormalizer);
+        $result = $normalizer->denormalize($source, []);
+
+        self::assertSame([1, 2, 3], $result);
+        self::assertSame([101, 102, 103], $source);
+    }
+
     public function testPassHydrator(): void
     {
         $hydrator = $this->createMock(Hydrator::class);