minor #54308 Add more explicit nullable types for default null values (alexandre-daubois)

This PR was merged into the 5.4 branch.

Discussion
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Add more explicit nullable types for default null values

| Q             | A
| ------------- | ---
| Branch?       | 5.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Issues        | -
| License       | MIT

Continuing to bring deprecation-free support for PHP 8.4 (https://php.watch/versions/8.4/implicitly-marking-parameter-type-nullable-deprecated)

If this gets merged, I'll take care of adding missing ones in upper branches if not done during upmerge 🙂

Commits
-------

e9d30bac03 Add more explicit nullable types for default null values

Author: nicolas-grekas

Tests/Fixtures/ChoiceList/DeprecatedChoiceListFactory.php

@@ -9,15 +9,15 @@
 
 class DeprecatedChoiceListFactory implements ChoiceListFactoryInterface
 {
-    public function createListFromChoices(iterable $choices, callable $value = null): ChoiceListInterface
+    public function createListFromChoices(iterable $choices, ?callable $value = null): ChoiceListInterface
     {
     }
 
-    public function createListFromLoader(ChoiceLoaderInterface $loader, callable $value = null): ChoiceListInterface
+    public function createListFromLoader(ChoiceLoaderInterface $loader, ?callable $value = null): ChoiceListInterface
     {
     }
 
-    public function createView(ChoiceListInterface $list, $preferredChoices = null, $label = null, callable $index = null, callable $groupBy = null, $attr = null): ChoiceListView
+    public function createView(ChoiceListInterface $list, $preferredChoices = null, $label = null, ?callable $index = null, ?callable $groupBy = null, $attr = null): ChoiceListView
     {
     }
 }

Tests/Fixtures/CustomArrayObject.php

@@ -19,7 +19,7 @@ class CustomArrayObject implements \ArrayAccess, \IteratorAggregate, \Countable,
 {
     private $array;
 
-    public function __construct(array $array = null)
+    public function __construct(?array $array = null)
     {
         $this->array = $array ?: [];
     }

Tests/Fixtures/FixedTranslator.php

@@ -22,7 +22,7 @@ public function __construct(array $translations)
         $this->translations = $translations;
     }
 
-    public function trans(string $id, array $parameters = [], string $domain = null, string $locale = null): string
+    public function trans(string $id, array $parameters = [], ?string $domain = null, ?string $locale = null): string
     {
         return $this->translations[$id] ?? $id;
     }