[PHP 8.4] Fixes for implicit nullability deprecation (yiisoft#20133)

Fixes all issues that emit deprecation notices on PHP 8.4 for implicit nullable parameter type declarations.
Related to yiisoft#20128.

See:
 - [RFC](https://wiki.php.net/rfc/deprecate-implicitly-nullable-types)
 - [PHP 8.4: Implicitly nullable parameter declarations deprecated](https://php.watch/versions/8.4/implicitly-marking-parameter-type-nullable-deprecated)

Co-authored-by: Wilmer Arambula <[email protected]>
Co-authored-by: Alexander Makarov <[email protected]>

Author: 3 people

framework/base/Component.php

@@ -605,7 +605,7 @@ public function off($name, $handler = null)
      * @param string $name the event name
      * @param Event|null $event the event instance. If not set, a default [[Event]] object will be created.
      */
-    public function trigger($name, Event $event = null)
+    public function trigger($name, ?Event $event = null)
     {
         $this->ensureBehaviors();
 

framework/db/ActiveQuery.php

@@ -785,7 +785,7 @@ public function orOnCondition($condition, $params = [])
      * @throws InvalidConfigException when query is not initialized properly
      * @see via()
      */
-    public function viaTable($tableName, $link, callable $callable = null)
+    public function viaTable($tableName, $link, ?callable $callable = null)
     {
         $modelClass = $this->primaryModel ? get_class($this->primaryModel) : $this->modelClass;
         $relation = new self($modelClass, [

framework/db/ActiveQueryInterface.php

@@ -97,7 +97,7 @@ public function with();
      * Its signature should be `function($query)`, where `$query` is the query to be customized.
      * @return $this the relation object itself.
      */
-    public function via($relationName, callable $callable = null);
+    public function via($relationName, ?callable $callable = null);
 
     /**
      * Finds the related records for the specified primary record.

framework/db/ActiveRelationTrait.php

@@ -104,7 +104,7 @@ public function __clone()
      * Its signature should be `function($query)`, where `$query` is the query to be customized.
      * @return $this the relation object itself.
      */
-    public function via($relationName, callable $callable = null)
+    public function via($relationName, ?callable $callable = null)
     {
         $relation = $this->primaryModel->getRelation($relationName);
         $callableUsed = $callable !== null;

framework/mail/BaseMessage.php

@@ -39,7 +39,7 @@ abstract class BaseMessage extends BaseObject implements MessageInterface
      * the "mailer" application component will be used instead.
      * @return bool whether this message is sent successfully.
      */
-    public function send(MailerInterface $mailer = null)
+    public function send(?MailerInterface $mailer = null)
     {
         if ($mailer === null && $this->mailer === null) {
             $mailer = Yii::$app->getMailer();

framework/mail/MessageInterface.php

@@ -209,7 +209,7 @@ public function embedContent($content, array $options = []);
      * If null, the "mailer" application component will be used instead.
      * @return bool whether this message is sent successfully.
      */
-    public function send(MailerInterface $mailer = null);
+    public function send(?MailerInterface $mailer = null);
 
     /**
      * Returns string representation of this message.

tests/framework/console/FakePhp71Controller.php

@@ -14,14 +14,9 @@
 
 class FakePhp71Controller extends Controller
 {
-    public function actionInjection(
-        $before,
-        Request $request,
-        $between,
-        DummyService $dummyService,
-        Post $post = null,
-        $after
-    ): void {
+    public function actionInjection($before, Request $request, $between, DummyService $dummyService, ?Post $post = null, $after)
+    {
+
     }
 
     public function actionNullableInjection(?Request $request, ?Post $post): void

tests/framework/di/ContainerTest.php

@@ -236,7 +236,9 @@ public function testOptionalDependencies(): void
     {
         $container = new Container();
         // Test optional unresolvable dependency.
-        $closure = fn(QuxInterface $test = null) => $test;
+        $closure = function (?QuxInterface $test = null) {
+            return $test;
+        };
         $this->assertNull($container->invoke($closure));
     }
 

tests/framework/di/stubs/Alpha.php

@@ -12,10 +12,10 @@ class Alpha extends BaseObject
     public $color = true;
 
     public function __construct(
-        Beta $beta = null,
-        QuxInterface $omega = null,
-        Unknown $unknown = null,
-        AbstractColor $color = null
+        ?Beta $beta = null,
+        ?QuxInterface $omega = null,
+        ?Unknown $unknown = null,
+        ?AbstractColor $color = null
     ) {
         $this->beta = $beta;
         $this->omega = $omega;

tests/framework/web/FakePhp71Controller.php

@@ -21,14 +21,9 @@ class FakePhp71Controller extends Controller
 {
     public $enableCsrfValidation = false;
 
-    public function actionInjection(
-        $before,
-        Request $request,
-        $between,
-        VendorImage $vendorImage,
-        Post $post = null,
-        $after
-    ): void {
+    public function actionInjection($before, Request $request, $between, VendorImage $vendorImage, ?Post $post = null, $after)
+    {
+
     }
 
     public function actionNullableInjection(?Request $request, ?Post $post): void