bug symfony#50251 [Serializer] Handle datetime deserialization in U format (tugmaks)

This PR was merged into the 5.4 branch.

Discussion
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[Serializer] Handle datetime deserialization in U format

| Q             | A
| ------------- | ---
| Branch?       | 5.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix symfony#50236
| License       | MIT
| Doc PR        | -

Fixes symfony#50236

Commits
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a5d1ca6 [Serializer] Handle datetime deserialization in U format

Author: nicolas-grekas

src/Symfony/Component/Serializer/Normalizer/DateTimeNormalizer.php

@@ -91,7 +91,14 @@ public function denormalize($data, string $type, string $format = null, array $c
         $dateTimeFormat = $context[self::FORMAT_KEY] ?? null;
         $timezone = $this->getTimezone($context);
 
-        if (null === $data || !\is_string($data) || '' === trim($data)) {
+        if (\is_int($data) || \is_float($data)) {
+            switch ($dateTimeFormat) {
+                case 'U': $data = sprintf('%d', $data); break;
+                case 'U.u': $data = sprintf('%.6F', $data); break;
+            }
+        }
+
+        if (!\is_string($data) || '' === trim($data)) {
             throw NotNormalizableValueException::createForUnexpectedDataType('The data is either not an string, an empty string, or null; you should pass a string that can be parsed with the passed format or a valid DateTime string.', $data, [Type::BUILTIN_TYPE_STRING], $context['deserialization_path'] ?? null, true);
         }
 

src/Symfony/Component/Serializer/Tests/Normalizer/DateTimeNormalizerTest.php

@@ -178,6 +178,8 @@ public function testDenormalize()
         $this->assertEquals(new \DateTimeImmutable('2016/01/01', new \DateTimeZone('UTC')), $this->normalizer->denormalize('2016-01-01T00:00:00+00:00', \DateTimeImmutable::class));
         $this->assertEquals(new \DateTime('2016/01/01', new \DateTimeZone('UTC')), $this->normalizer->denormalize('2016-01-01T00:00:00+00:00', \DateTime::class));
         $this->assertEquals(new \DateTime('2016/01/01', new \DateTimeZone('UTC')), $this->normalizer->denormalize('  2016-01-01T00:00:00+00:00  ', \DateTime::class));
+        $this->assertEquals(new \DateTimeImmutable('2023-05-06T17:35:34.000000+0000', new \DateTimeZone('UTC')), $this->normalizer->denormalize(1683394534, \DateTimeImmutable::class, null, [DateTimeNormalizer::FORMAT_KEY => 'U']));
+        $this->assertEquals(new \DateTimeImmutable('2023-05-06T17:35:34.123400+0000', new \DateTimeZone('UTC')), $this->normalizer->denormalize(1683394534.1234, \DateTimeImmutable::class, null, [DateTimeNormalizer::FORMAT_KEY => 'U.u']));
     }
 
     public function testDenormalizeUsingTimezonePassedInConstructor()