From 1564887547bae32a17080e3d2f658f6a2762790b Mon Sep 17 00:00:00 2001
From: Nicolas Grekas <nicolas.grekas@gmail.com>
Date: Thu, 12 Aug 2021 16:46:41 +0200
Subject: [PATCH] Add return types - batch 1/n

---
 .../Cache/Adapter/AbstractAdapter.php         |  4 +-
 .../Cache/Adapter/AbstractTagAwareAdapter.php |  2 +-
 .../Component/Cache/Adapter/ApcuAdapter.php   | 10 +--
 .../Component/Cache/Adapter/ChainAdapter.php  |  2 +-
 .../Cache/Adapter/CouchbaseBucketAdapter.php  |  4 +-
 .../Cache/Adapter/DoctrineAdapter.php         | 10 +--
 .../Adapter/FilesystemTagAwareAdapter.php     |  2 +-
 .../Cache/Adapter/MemcachedAdapter.php        | 14 ++---
 .../Component/Cache/Adapter/PdoAdapter.php    | 12 ++--
 .../Cache/Adapter/PhpArrayAdapter.php         |  4 +-
 .../Cache/Adapter/PhpFilesAdapter.php         | 15 ++---
 .../Component/Cache/Adapter/Psr16Adapter.php  | 10 +--
 .../Cache/Adapter/TagAwareAdapter.php         |  5 +-
 .../Cache/Adapter/TraceableAdapter.php        |  2 +-
 .../Cache/Marshaller/DefaultMarshaller.php    |  2 +-
 .../Cache/Marshaller/DeflateMarshaller.php    |  2 +-
 .../Cache/Marshaller/MarshallerInterface.php  |  4 +-
 .../Cache/Marshaller/SodiumMarshaller.php     |  2 +-
 .../Cache/Marshaller/TagAwareMarshaller.php   |  2 +-
 .../Component/Cache/PruneableInterface.php    |  5 +-
 .../Cache/Traits/AbstractAdapterTrait.php     | 15 ++---
 .../Cache/Traits/FilesystemCommonTrait.php    |  9 +--
 .../Cache/Traits/FilesystemTrait.php          | 11 ++--
 .../Component/Cache/Traits/ProxyTrait.php     |  2 +-
 .../Component/Cache/Traits/RedisTrait.php     | 14 ++---
 .../ErrorHandler/BufferingLogger.php          |  5 +-
 .../Exception/FlattenException.php            | 35 +++++------
 .../Filesystem/Exception/IOException.php      |  2 +-
 .../Exception/IOExceptionInterface.php        |  2 +-
 .../Component/Filesystem/Filesystem.php       | 14 ++---
 .../Component/HttpClient/HttpOptions.php      | 56 ++++++++---------
 .../Reader/BundleEntryReaderInterface.php     |  2 +-
 .../Bundle/Reader/BundleReaderInterface.php   |  2 +-
 .../Component/Intl/Util/IcuVersion.php        |  4 +-
 src/Symfony/Component/Intl/Util/Version.php   |  4 +-
 src/Symfony/Component/Lock/LockInterface.php  |  8 +--
 .../Lock/PersistingStoreInterface.php         |  2 +-
 .../Component/Lock/SharedLockInterface.php    |  2 +-
 .../Component/Lock/Store/CombinedStore.php    |  2 +-
 .../Component/Lock/Store/FlockStore.php       |  2 +-
 .../Component/Lock/Store/InMemoryStore.php    |  2 +-
 .../Component/Lock/Store/MemcachedStore.php   |  2 +-
 src/Symfony/Component/Lock/Store/PdoStore.php |  2 +-
 .../Component/Lock/Store/PostgreSqlStore.php  |  2 +-
 .../Component/Lock/Store/RedisStore.php       |  2 +-
 .../Component/Lock/Store/SemaphoreStore.php   |  2 +-
 .../Component/Lock/Store/StoreFactory.php     |  2 +-
 .../Lock/Strategy/ConsensusStrategy.php       |  4 +-
 .../Lock/Strategy/StrategyInterface.php       |  4 +-
 .../Lock/Strategy/UnanimousStrategy.php       |  4 +-
 .../Component/Runtime/GenericRuntime.php      |  2 +-
 .../Component/Runtime/SymfonyRuntime.php      |  2 +-
 src/Symfony/Component/Stopwatch/Section.php   | 20 +++---
 src/Symfony/Component/Stopwatch/Stopwatch.php | 14 ++---
 .../Component/Stopwatch/StopwatchEvent.php    | 24 +++----
 .../Component/Stopwatch/StopwatchPeriod.php   |  8 +--
 .../Component/String/AbstractString.php       | 62 +++++++++----------
 .../String/AbstractUnicodeString.php          | 34 +++++-----
 src/Symfony/Component/String/ByteString.php   | 40 ++++++------
 .../Component/String/CodePointString.php      | 10 +--
 src/Symfony/Component/String/LazyString.php   |  4 +-
 .../Component/String/UnicodeString.php        | 16 ++---
 .../VarDumper/Cloner/AbstractCloner.php       |  8 +--
 .../VarDumper/Cloner/ClonerInterface.php      |  2 +-
 .../Component/VarDumper/Cloner/Data.php       | 16 ++---
 .../Component/VarDumper/Cloner/VarCloner.php  |  2 +-
 .../VarDumper/Dumper/AbstractDumper.php       |  8 +--
 .../Component/VarDumper/Dumper/CliDumper.php  |  4 +-
 .../Component/VarDumper/Dumper/HtmlDumper.php |  4 +-
 .../Component/WebLink/GenericLinkProvider.php |  4 +-
 src/Symfony/Component/WebLink/Link.php        | 10 +--
 .../Component/Workflow/DefinitionBuilder.php  | 16 ++---
 .../Workflow/Dumper/DumperInterface.php       |  2 +-
 .../Workflow/Dumper/GraphvizDumper.php        |  2 +-
 .../Dumper/StateMachineGraphvizDumper.php     |  2 +-
 .../EventListener/AuditTrailListener.php      |  2 +-
 .../MarkingStore/MarkingStoreInterface.php    |  2 +-
 src/Symfony/Component/Workflow/Registry.php   |  2 +-
 .../Component/Workflow/Tests/WorkflowTest.php | 11 ----
 src/Symfony/Component/Workflow/Transition.php |  6 +-
 src/Symfony/Component/Workflow/Workflow.php   | 14 ++---
 .../Component/Workflow/WorkflowInterface.php  | 14 ++---
 .../Component/Yaml/Command/LintCommand.php    |  2 +-
 .../Yaml/Exception/ParseException.php         |  6 +-
 84 files changed, 327 insertions(+), 380 deletions(-)

diff --git a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
index 6e09cdb96a5a7..c919e574308f7 100644
--- a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
@@ -98,10 +98,8 @@ static function ($deferred, $namespace, &$expiredIds, $getId, $defaultLifetime)
      * Returns the best possible adapter that your runtime supports.
      *
      * Using ApcuAdapter makes system caches compatible with read-only filesystems.
-     *
-     * @return AdapterInterface
      */
-    public static function createSystemCache(string $namespace, int $defaultLifetime, string $version, string $directory, LoggerInterface $logger = null)
+    public static function createSystemCache(string $namespace, int $defaultLifetime, string $version, string $directory, LoggerInterface $logger = null): AdapterInterface
     {
         $opcache = new PhpFilesAdapter($namespace, $defaultLifetime, $directory, true);
         if (null !== $logger) {
diff --git a/src/Symfony/Component/Cache/Adapter/AbstractTagAwareAdapter.php b/src/Symfony/Component/Cache/Adapter/AbstractTagAwareAdapter.php
index 42ae7a987a772..cbc0a458bd543 100644
--- a/src/Symfony/Component/Cache/Adapter/AbstractTagAwareAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/AbstractTagAwareAdapter.php
@@ -138,7 +138,7 @@ abstract protected function doSave(array $values, int $lifetime, array $addTagDa
      *
      * @return bool True if the items were successfully removed, false otherwise
      */
-    abstract protected function doDelete(array $ids);
+    abstract protected function doDelete(array $ids): bool;
 
     /**
      * Removes relations between tags and deleted items.
diff --git a/src/Symfony/Component/Cache/Adapter/ApcuAdapter.php b/src/Symfony/Component/Cache/Adapter/ApcuAdapter.php
index dc6279e8ba7dd..77e8a70cbcd48 100644
--- a/src/Symfony/Component/Cache/Adapter/ApcuAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/ApcuAdapter.php
@@ -55,7 +55,7 @@ public static function isSupported()
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         $unserializeCallbackHandler = ini_set('unserialize_callback_func', __CLASS__.'::handleUnserializeCallback');
         try {
@@ -77,7 +77,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         return apcu_exists($id);
     }
@@ -85,7 +85,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         return isset($namespace[0]) && class_exists(\APCuIterator::class, false) && ('cli' !== \PHP_SAPI || filter_var(ini_get('apc.enable_cli'), \FILTER_VALIDATE_BOOLEAN))
             ? apcu_delete(new \APCuIterator(sprintf('/^%s/', preg_quote($namespace, '/')), \APC_ITER_KEY))
@@ -95,7 +95,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         foreach ($ids as $id) {
             apcu_delete($id);
@@ -107,7 +107,7 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         if (null !== $this->marshaller && (!$values = $this->marshaller->marshall($values, $failed))) {
             return $failed;
diff --git a/src/Symfony/Component/Cache/Adapter/ChainAdapter.php b/src/Symfony/Component/Cache/Adapter/ChainAdapter.php
index f0782e3ea633d..925e9f2f6b5bc 100644
--- a/src/Symfony/Component/Cache/Adapter/ChainAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/ChainAdapter.php
@@ -292,7 +292,7 @@ public function commit(): bool
     /**
      * {@inheritdoc}
      */
-    public function prune()
+    public function prune(): bool
     {
         $pruned = true;
 
diff --git a/src/Symfony/Component/Cache/Adapter/CouchbaseBucketAdapter.php b/src/Symfony/Component/Cache/Adapter/CouchbaseBucketAdapter.php
index 5cd25f422e541..82957a8ca24c0 100644
--- a/src/Symfony/Component/Cache/Adapter/CouchbaseBucketAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/CouchbaseBucketAdapter.php
@@ -161,7 +161,7 @@ private static function initOptions(array $options): array
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         $resultsCouchbase = $this->bucket->get($ids);
 
@@ -218,7 +218,7 @@ protected function doDelete(array $ids): bool
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         if (!$values = $this->marshaller->marshall($values, $failed)) {
             return $failed;
diff --git a/src/Symfony/Component/Cache/Adapter/DoctrineAdapter.php b/src/Symfony/Component/Cache/Adapter/DoctrineAdapter.php
index 2bd8978401505..908498c59ae13 100644
--- a/src/Symfony/Component/Cache/Adapter/DoctrineAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/DoctrineAdapter.php
@@ -39,7 +39,7 @@ public function reset()
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         $unserializeCallbackHandler = ini_set('unserialize_callback_func', parent::class.'::handleUnserializeCallback');
         try {
@@ -65,7 +65,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         return $this->provider->contains($id);
     }
@@ -73,7 +73,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         $namespace = $this->provider->getNamespace();
 
@@ -85,7 +85,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         $ok = true;
         foreach ($ids as $id) {
@@ -98,7 +98,7 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         return $this->provider->saveMultiple($values, $lifetime);
     }
diff --git a/src/Symfony/Component/Cache/Adapter/FilesystemTagAwareAdapter.php b/src/Symfony/Component/Cache/Adapter/FilesystemTagAwareAdapter.php
index c06557d323596..140c91f48ddea 100644
--- a/src/Symfony/Component/Cache/Adapter/FilesystemTagAwareAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/FilesystemTagAwareAdapter.php
@@ -44,7 +44,7 @@ public function __construct(string $namespace = '', int $defaultLifetime = 0, st
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         $ok = $this->doClearCache($namespace);
 
diff --git a/src/Symfony/Component/Cache/Adapter/MemcachedAdapter.php b/src/Symfony/Component/Cache/Adapter/MemcachedAdapter.php
index 0590af3c00461..2d484895a5324 100644
--- a/src/Symfony/Component/Cache/Adapter/MemcachedAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/MemcachedAdapter.php
@@ -92,11 +92,9 @@ public static function isSupported()
      * @param array[]|string|string[] $servers An array of servers, a DSN, or an array of DSNs
      * @param array                   $options An array of options
      *
-     * @return \Memcached
-     *
      * @throws \ErrorException When invalid options or servers are provided
      */
-    public static function createConnection(array|string $servers, array $options = [])
+    public static function createConnection(array|string $servers, array $options = []): \Memcached
     {
         if (\is_string($servers)) {
             $servers = [$servers];
@@ -243,7 +241,7 @@ public static function createConnection(array|string $servers, array $options =
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         if (!$values = $this->marshaller->marshall($values, $failed)) {
             return $failed;
@@ -264,7 +262,7 @@ protected function doSave(array $values, int $lifetime)
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         try {
             $encodedIds = array_map('self::encodeKey', $ids);
@@ -285,7 +283,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         return false !== $this->getClient()->get(self::encodeKey($id)) || $this->checkResultCode(\Memcached::RES_SUCCESS === $this->client->getResultCode());
     }
@@ -293,7 +291,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         $ok = true;
         $encodedIds = array_map('self::encodeKey', $ids);
@@ -309,7 +307,7 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         return '' === $namespace && $this->getClient()->flush();
     }
diff --git a/src/Symfony/Component/Cache/Adapter/PdoAdapter.php b/src/Symfony/Component/Cache/Adapter/PdoAdapter.php
index 3bd4f7ea92c9a..dc64545d98f5b 100644
--- a/src/Symfony/Component/Cache/Adapter/PdoAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/PdoAdapter.php
@@ -181,7 +181,7 @@ public function configureSchema(Schema $schema, Connection $forConnection): void
     /**
      * {@inheritdoc}
      */
-    public function prune()
+    public function prune(): bool
     {
         $deleteSql = "DELETE FROM $this->table WHERE $this->lifetimeCol + $this->timeCol <= :time";
 
@@ -213,7 +213,7 @@ public function prune()
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         $now = time();
         $expired = [];
@@ -257,7 +257,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         $sql = "SELECT 1 FROM $this->table WHERE $this->idCol = :id AND ($this->lifetimeCol IS NULL OR $this->lifetimeCol + $this->timeCol > :time)";
         $stmt = $this->getConnection()->prepare($sql);
@@ -272,7 +272,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         $conn = $this->getConnection();
 
@@ -302,7 +302,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         $sql = str_pad('', (\count($ids) << 1) - 1, '?,');
         $sql = "DELETE FROM $this->table WHERE $this->idCol IN ($sql)";
@@ -319,7 +319,7 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         if (!$values = $this->marshaller->marshall($values, $failed)) {
             return $failed;
diff --git a/src/Symfony/Component/Cache/Adapter/PhpArrayAdapter.php b/src/Symfony/Component/Cache/Adapter/PhpArrayAdapter.php
index 1e5d1fc2eeec4..99a450b0db607 100644
--- a/src/Symfony/Component/Cache/Adapter/PhpArrayAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/PhpArrayAdapter.php
@@ -68,10 +68,8 @@ static function ($key, $value, $isHit) {
      *
      * @param string                 $file         The PHP file were values are cached
      * @param CacheItemPoolInterface $fallbackPool A pool to fallback on when an item is not hit
-     *
-     * @return CacheItemPoolInterface
      */
-    public static function create(string $file, CacheItemPoolInterface $fallbackPool)
+    public static function create(string $file, CacheItemPoolInterface $fallbackPool): CacheItemPoolInterface
     {
         if (!$fallbackPool instanceof AdapterInterface) {
             $fallbackPool = new ProxyAdapter($fallbackPool);
diff --git a/src/Symfony/Component/Cache/Adapter/PhpFilesAdapter.php b/src/Symfony/Component/Cache/Adapter/PhpFilesAdapter.php
index 7e735f2837e25..8e5c34a2d102b 100644
--- a/src/Symfony/Component/Cache/Adapter/PhpFilesAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/PhpFilesAdapter.php
@@ -61,10 +61,7 @@ public static function isSupported()
         return \function_exists('opcache_invalidate') && filter_var(ini_get('opcache.enable'), \FILTER_VALIDATE_BOOLEAN) && (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true) || filter_var(ini_get('opcache.enable_cli'), \FILTER_VALIDATE_BOOLEAN));
     }
 
-    /**
-     * @return bool
-     */
-    public function prune()
+    public function prune(): bool
     {
         $time = time();
         $pruned = true;
@@ -95,7 +92,7 @@ public function prune()
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         if ($this->appendOnly) {
             $now = 0;
@@ -171,7 +168,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         if ($this->appendOnly && isset($this->values[$id])) {
             return true;
@@ -211,7 +208,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         $ok = true;
         $expiry = $lifetime ? time() + $lifetime : 'PHP_INT_MAX';
@@ -273,7 +270,7 @@ protected function doSave(array $values, int $lifetime)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         $this->values = [];
 
@@ -283,7 +280,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         foreach ($ids as $id) {
             unset($this->values[$id]);
diff --git a/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php b/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php
index f51604baa0d91..664c18bba4474 100644
--- a/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php
+++ b/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php
@@ -43,7 +43,7 @@ public function __construct(CacheInterface $pool, string $namespace = '', int $d
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         foreach ($this->pool->getMultiple($ids, $this->miss) as $key => $value) {
             if ($this->miss !== $value) {
@@ -55,7 +55,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         return $this->pool->has($id);
     }
@@ -63,7 +63,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         return $this->pool->clear();
     }
@@ -71,7 +71,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         return $this->pool->deleteMultiple($ids);
     }
@@ -79,7 +79,7 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         return $this->pool->setMultiple($values, 0 === $lifetime ? null : $lifetime);
     }
diff --git a/src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php b/src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php
index 6966402bfc1d6..e21b1372aa29b 100644
--- a/src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php
@@ -297,10 +297,7 @@ public function commit(): bool
         return $this->invalidateTags([]);
     }
 
-    /**
-     * @return array
-     */
-    public function __sleep()
+    public function __sleep(): array
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
     }
diff --git a/src/Symfony/Component/Cache/Adapter/TraceableAdapter.php b/src/Symfony/Component/Cache/Adapter/TraceableAdapter.php
index ba69f68fb16b8..5e68907bfd8d7 100644
--- a/src/Symfony/Component/Cache/Adapter/TraceableAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/TraceableAdapter.php
@@ -212,7 +212,7 @@ public function commit(): bool
     /**
      * {@inheritdoc}
      */
-    public function prune()
+    public function prune(): bool
     {
         if (!$this->pool instanceof PruneableInterface) {
             return false;
diff --git a/src/Symfony/Component/Cache/Marshaller/DefaultMarshaller.php b/src/Symfony/Component/Cache/Marshaller/DefaultMarshaller.php
index a9630176592f8..4cd1a5f0e8d89 100644
--- a/src/Symfony/Component/Cache/Marshaller/DefaultMarshaller.php
+++ b/src/Symfony/Component/Cache/Marshaller/DefaultMarshaller.php
@@ -57,7 +57,7 @@ public function marshall(array $values, ?array &$failed): array
     /**
      * {@inheritdoc}
      */
-    public function unmarshall(string $value)
+    public function unmarshall(string $value): mixed
     {
         if ('b:0;' === $value) {
             return false;
diff --git a/src/Symfony/Component/Cache/Marshaller/DeflateMarshaller.php b/src/Symfony/Component/Cache/Marshaller/DeflateMarshaller.php
index 83cd148db3a4b..95e3d320694aa 100644
--- a/src/Symfony/Component/Cache/Marshaller/DeflateMarshaller.php
+++ b/src/Symfony/Component/Cache/Marshaller/DeflateMarshaller.php
@@ -42,7 +42,7 @@ public function marshall(array $values, ?array &$failed): array
     /**
      * {@inheritdoc}
      */
-    public function unmarshall(string $value)
+    public function unmarshall(string $value): mixed
     {
         if (false !== $inflatedValue = @gzinflate($value)) {
             $value = $inflatedValue;
diff --git a/src/Symfony/Component/Cache/Marshaller/MarshallerInterface.php b/src/Symfony/Component/Cache/Marshaller/MarshallerInterface.php
index cdd6c4022ca4f..5b81aad2d8582 100644
--- a/src/Symfony/Component/Cache/Marshaller/MarshallerInterface.php
+++ b/src/Symfony/Component/Cache/Marshaller/MarshallerInterface.php
@@ -32,9 +32,7 @@ public function marshall(array $values, ?array &$failed): array;
     /**
      * Unserializes a single value and throws an exception if anything goes wrong.
      *
-     * @return mixed
-     *
      * @throws \Exception Whenever unserialization fails
      */
-    public function unmarshall(string $value);
+    public function unmarshall(string $value): mixed;
 }
diff --git a/src/Symfony/Component/Cache/Marshaller/SodiumMarshaller.php b/src/Symfony/Component/Cache/Marshaller/SodiumMarshaller.php
index 8a317e33868ac..4d8a04ee6da45 100644
--- a/src/Symfony/Component/Cache/Marshaller/SodiumMarshaller.php
+++ b/src/Symfony/Component/Cache/Marshaller/SodiumMarshaller.php
@@ -66,7 +66,7 @@ public function marshall(array $values, ?array &$failed): array
     /**
      * {@inheritdoc}
      */
-    public function unmarshall(string $value)
+    public function unmarshall(string $value): mixed
     {
         foreach ($this->decryptionKeys as $k) {
             if (false !== $decryptedValue = @sodium_crypto_box_seal_open($value, $k)) {
diff --git a/src/Symfony/Component/Cache/Marshaller/TagAwareMarshaller.php b/src/Symfony/Component/Cache/Marshaller/TagAwareMarshaller.php
index 9db211cf60cc7..60961538584e2 100644
--- a/src/Symfony/Component/Cache/Marshaller/TagAwareMarshaller.php
+++ b/src/Symfony/Component/Cache/Marshaller/TagAwareMarshaller.php
@@ -67,7 +67,7 @@ public function marshall(array $values, ?array &$failed): array
     /**
      * {@inheritdoc}
      */
-    public function unmarshall(string $value)
+    public function unmarshall(string $value): mixed
     {
         // detect the compact format used in marshall() using magic numbers in the form 9D-..-..-..-..-00-..-..-..-5F
         if (13 >= \strlen($value) || "\x9D" !== $value[0] || "\0" !== $value[5] || "\x5F" !== $value[9]) {
diff --git a/src/Symfony/Component/Cache/PruneableInterface.php b/src/Symfony/Component/Cache/PruneableInterface.php
index 42615253689fe..3095c80f40c85 100644
--- a/src/Symfony/Component/Cache/PruneableInterface.php
+++ b/src/Symfony/Component/Cache/PruneableInterface.php
@@ -16,8 +16,5 @@
  */
 interface PruneableInterface
 {
-    /**
-     * @return bool
-     */
-    public function prune();
+    public function prune(): bool;
 }
diff --git a/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php b/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php
index 01dd5aaf998ee..ae029da5d47d1 100644
--- a/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php
+++ b/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php
@@ -54,7 +54,7 @@ trait AbstractAdapterTrait
      *
      * @return array|\Traversable The corresponding values found in the cache
      */
-    abstract protected function doFetch(array $ids);
+    abstract protected function doFetch(array $ids): iterable;
 
     /**
      * Confirms if the cache contains specified cache item.
@@ -63,7 +63,7 @@ abstract protected function doFetch(array $ids);
      *
      * @return bool True if item exists in the cache, false otherwise
      */
-    abstract protected function doHave(string $id);
+    abstract protected function doHave(string $id): bool;
 
     /**
      * Deletes all items in the pool.
@@ -72,7 +72,7 @@ abstract protected function doHave(string $id);
      *
      * @return bool True if the pool was successfully cleared, false otherwise
      */
-    abstract protected function doClear(string $namespace);
+    abstract protected function doClear(string $namespace): bool;
 
     /**
      * Removes multiple items from the pool.
@@ -81,7 +81,7 @@ abstract protected function doClear(string $namespace);
      *
      * @return bool True if the items were successfully removed, false otherwise
      */
-    abstract protected function doDelete(array $ids);
+    abstract protected function doDelete(array $ids): bool;
 
     /**
      * Persists several cache items immediately.
@@ -91,7 +91,7 @@ abstract protected function doDelete(array $ids);
      *
      * @return array|bool The identifiers that failed to be cached or a boolean stating if caching succeeded or not
      */
-    abstract protected function doSave(array $values, int $lifetime);
+    abstract protected function doSave(array $values, int $lifetime): array|bool;
 
     /**
      * {@inheritdoc}
@@ -303,10 +303,7 @@ public function reset()
         $this->ids = [];
     }
 
-    /**
-     * @return array
-     */
-    public function __sleep()
+    public function __sleep(): array
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
     }
diff --git a/src/Symfony/Component/Cache/Traits/FilesystemCommonTrait.php b/src/Symfony/Component/Cache/Traits/FilesystemCommonTrait.php
index 50e6bdb647567..40d6f43a1aedd 100644
--- a/src/Symfony/Component/Cache/Traits/FilesystemCommonTrait.php
+++ b/src/Symfony/Component/Cache/Traits/FilesystemCommonTrait.php
@@ -53,7 +53,7 @@ private function init(string $namespace, ?string $directory)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         $ok = true;
 
@@ -71,7 +71,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         $ok = true;
 
@@ -171,10 +171,7 @@ public static function throwError(int $type, string $message, string $file, int
         throw new \ErrorException($message, 0, $type, $file, $line);
     }
 
-    /**
-     * @return array
-     */
-    public function __sleep()
+    public function __sleep(): array
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
     }
diff --git a/src/Symfony/Component/Cache/Traits/FilesystemTrait.php b/src/Symfony/Component/Cache/Traits/FilesystemTrait.php
index 3c55234850c08..05ad8ed674a64 100644
--- a/src/Symfony/Component/Cache/Traits/FilesystemTrait.php
+++ b/src/Symfony/Component/Cache/Traits/FilesystemTrait.php
@@ -26,10 +26,7 @@ trait FilesystemTrait
 
     private MarshallerInterface $marshaller;
 
-    /**
-     * @return bool
-     */
-    public function prune()
+    public function prune(): bool
     {
         $time = time();
         $pruned = true;
@@ -53,7 +50,7 @@ public function prune()
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         $values = [];
         $now = time();
@@ -82,7 +79,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         $file = $this->getFile($id);
 
@@ -92,7 +89,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         $expiresAt = $lifetime ? (time() + $lifetime) : 0;
         $values = $this->marshaller->marshall($values, $failed);
diff --git a/src/Symfony/Component/Cache/Traits/ProxyTrait.php b/src/Symfony/Component/Cache/Traits/ProxyTrait.php
index 8ca264ae0a964..ba6f8cba90e13 100644
--- a/src/Symfony/Component/Cache/Traits/ProxyTrait.php
+++ b/src/Symfony/Component/Cache/Traits/ProxyTrait.php
@@ -26,7 +26,7 @@ trait ProxyTrait
     /**
      * {@inheritdoc}
      */
-    public function prune()
+    public function prune(): bool
     {
         return $this->pool instanceof PruneableInterface && $this->pool->prune();
     }
diff --git a/src/Symfony/Component/Cache/Traits/RedisTrait.php b/src/Symfony/Component/Cache/Traits/RedisTrait.php
index 7a70095a6b59b..a928fafc1e2b1 100644
--- a/src/Symfony/Component/Cache/Traits/RedisTrait.php
+++ b/src/Symfony/Component/Cache/Traits/RedisTrait.php
@@ -77,11 +77,9 @@ private function init(\Redis|\RedisArray|\RedisCluster|\Predis\ClientInterface|R
      *
      * @param array $options See self::$defaultConnectionOptions
      *
-     * @return \Redis|\RedisArray|\RedisCluster|RedisClusterProxy|RedisProxy|\Predis\ClientInterface According to the "class" option
-     *
      * @throws InvalidArgumentException when the DSN is invalid
      */
-    public static function createConnection(string $dsn, array $options = [])
+    public static function createConnection(string $dsn, array $options = []): \Redis|\RedisArray|\RedisCluster|RedisClusterProxy|RedisProxy|\Predis\ClientInterface
     {
         if (str_starts_with($dsn, 'redis:')) {
             $scheme = 'redis';
@@ -320,7 +318,7 @@ public static function createConnection(string $dsn, array $options = [])
     /**
      * {@inheritdoc}
      */
-    protected function doFetch(array $ids)
+    protected function doFetch(array $ids): iterable
     {
         if (!$ids) {
             return [];
@@ -356,7 +354,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave(string $id)
+    protected function doHave(string $id): bool
     {
         return (bool) $this->redis->exists($id);
     }
@@ -364,7 +362,7 @@ protected function doHave(string $id)
     /**
      * {@inheritdoc}
      */
-    protected function doClear(string $namespace)
+    protected function doClear(string $namespace): bool
     {
         if ($this->redis instanceof \Predis\ClientInterface) {
             $prefix = $this->redis->getOptions()->prefix ? $this->redis->getOptions()->prefix->getPrefix() : '';
@@ -428,7 +426,7 @@ protected function doClear(string $namespace)
     /**
      * {@inheritdoc}
      */
-    protected function doDelete(array $ids)
+    protected function doDelete(array $ids): bool
     {
         if (!$ids) {
             return true;
@@ -465,7 +463,7 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, int $lifetime)
+    protected function doSave(array $values, int $lifetime): array|bool
     {
         if (!$values = $this->marshaller->marshall($values, $failed)) {
             return $failed;
diff --git a/src/Symfony/Component/ErrorHandler/BufferingLogger.php b/src/Symfony/Component/ErrorHandler/BufferingLogger.php
index 8f9ae5025c0df..d1fd9ed29e4ee 100644
--- a/src/Symfony/Component/ErrorHandler/BufferingLogger.php
+++ b/src/Symfony/Component/ErrorHandler/BufferingLogger.php
@@ -35,10 +35,7 @@ public function cleanLogs(): array
         return $logs;
     }
 
-    /**
-     * @return array
-     */
-    public function __sleep()
+    public function __sleep(): array
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
     }
diff --git a/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php b/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
index fc4abccdf8f48..6087c374b9fb7 100644
--- a/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
+++ b/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
@@ -60,18 +60,12 @@ class FlattenException
     /** @var string|null */
     private $asString;
 
-    /**
-     * @return static
-     */
-    public static function create(\Exception $exception, int $statusCode = null, array $headers = []): self
+    public static function create(\Exception $exception, int $statusCode = null, array $headers = []): static
     {
         return static::createFromThrowable($exception, $statusCode, $headers);
     }
 
-    /**
-     * @return static
-     */
-    public static function createFromThrowable(\Throwable $exception, int $statusCode = null, array $headers = []): self
+    public static function createFromThrowable(\Throwable $exception, int $statusCode = null, array $headers = []): static
     {
         $e = new static();
         $e->setMessage($exception->getMessage());
@@ -133,7 +127,7 @@ public function getStatusCode(): int
     /**
      * @return $this
      */
-    public function setStatusCode(int $code): self
+    public function setStatusCode(int $code): static
     {
         $this->statusCode = $code;
 
@@ -148,7 +142,7 @@ public function getHeaders(): array
     /**
      * @return $this
      */
-    public function setHeaders(array $headers): self
+    public function setHeaders(array $headers): static
     {
         $this->headers = $headers;
 
@@ -163,7 +157,7 @@ public function getClass(): string
     /**
      * @return $this
      */
-    public function setClass(string $class): self
+    public function setClass(string $class): static
     {
         $this->class = str_contains($class, "@anonymous\0") ? (get_parent_class($class) ?: key(class_implements($class)) ?: 'class').'@anonymous' : $class;
 
@@ -178,7 +172,7 @@ public function getFile(): string
     /**
      * @return $this
      */
-    public function setFile(string $file): self
+    public function setFile(string $file): static
     {
         $this->file = $file;
 
@@ -193,7 +187,7 @@ public function getLine(): int
     /**
      * @return $this
      */
-    public function setLine(int $line): self
+    public function setLine(int $line): static
     {
         $this->line = $line;
 
@@ -220,7 +214,7 @@ public function getMessage(): string
     /**
      * @return $this
      */
-    public function setMessage(string $message): self
+    public function setMessage(string $message): static
     {
         if (str_contains($message, "@anonymous\0")) {
             $message = preg_replace_callback('/[a-zA-Z_\x7f-\xff][\\\\a-zA-Z0-9_\x7f-\xff]*+@anonymous\x00.*?\.php(?:0x?|:[0-9]++\$)[0-9a-fA-F]++/', function ($m) {
@@ -236,7 +230,7 @@ public function setMessage(string $message): self
     /**
      * @return int|string int most of the time (might be a string with PDOException)
      */
-    public function getCode()
+    public function getCode(): int|string
     {
         return $this->code;
     }
@@ -244,7 +238,7 @@ public function getCode()
     /**
      * @return $this
      */
-    public function setCode(int|string $code): self
+    public function setCode(int|string $code): static
     {
         $this->code = $code;
 
@@ -259,7 +253,7 @@ public function getPrevious(): ?self
     /**
      * @return $this
      */
-    public function setPrevious(self $previous): self
+    public function setPrevious(self $previous): static
     {
         $this->previous = $previous;
 
@@ -288,7 +282,7 @@ public function getTrace(): array
     /**
      * @return $this
      */
-    public function setTraceFromThrowable(\Throwable $throwable): self
+    public function setTraceFromThrowable(\Throwable $throwable): static
     {
         $this->traceAsString = $throwable->getTraceAsString();
 
@@ -296,10 +290,9 @@ public function setTraceFromThrowable(\Throwable $throwable): self
     }
 
     /**
-     *
      * @return $this
      */
-    public function setTrace(array $trace, ?string $file, ?int $line): self
+    public function setTrace(array $trace, ?string $file, ?int $line): static
     {
         $this->trace = [];
         $this->trace[] = [
@@ -386,7 +379,7 @@ public function getTraceAsString(): string
     /**
      * @return $this
      */
-    public function setAsString(?string $asString): self
+    public function setAsString(?string $asString): static
     {
         $this->asString = $asString;
 
diff --git a/src/Symfony/Component/Filesystem/Exception/IOException.php b/src/Symfony/Component/Filesystem/Exception/IOException.php
index 3043ee2cafee7..bcca860de498b 100644
--- a/src/Symfony/Component/Filesystem/Exception/IOException.php
+++ b/src/Symfony/Component/Filesystem/Exception/IOException.php
@@ -32,7 +32,7 @@ public function __construct(string $message, int $code = 0, \Throwable $previous
     /**
      * {@inheritdoc}
      */
-    public function getPath()
+    public function getPath(): ?string
     {
         return $this->path;
     }
diff --git a/src/Symfony/Component/Filesystem/Exception/IOExceptionInterface.php b/src/Symfony/Component/Filesystem/Exception/IOExceptionInterface.php
index f9d4644a87279..6e5d006eea510 100644
--- a/src/Symfony/Component/Filesystem/Exception/IOExceptionInterface.php
+++ b/src/Symfony/Component/Filesystem/Exception/IOExceptionInterface.php
@@ -23,5 +23,5 @@ interface IOExceptionInterface extends ExceptionInterface
      *
      * @return string|null The path
      */
-    public function getPath();
+    public function getPath(): ?string;
 }
diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index 7acf53073a6ab..a6014112da2c5 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -102,7 +102,7 @@ public function mkdir(string|iterable $dirs, int $mode = 0777)
      *
      * @return bool true if the file exists, false otherwise
      */
-    public function exists(string|iterable $files)
+    public function exists(string|iterable $files): bool
     {
         $maxPathLength = \PHP_MAXPATHLEN - 2;
 
@@ -399,10 +399,8 @@ private function linkException(string $origin, string $target, string $linkType)
      * With $canonicalize = true
      *      - if $path does not exist, returns null
      *      - if $path exists, returns its absolute fully resolved final version
-     *
-     * @return string|null
      */
-    public function readlink(string $path, bool $canonicalize = false)
+    public function readlink(string $path, bool $canonicalize = false): ?string
     {
         if (!$canonicalize && !is_link($path)) {
             return null;
@@ -424,7 +422,7 @@ public function readlink(string $path, bool $canonicalize = false)
      *
      * @return string Path of target relative to starting path
      */
-    public function makePathRelative(string $endPath, string $startPath)
+    public function makePathRelative(string $endPath, string $startPath): string
     {
         if (!$this->isAbsolutePath($startPath)) {
             throw new InvalidArgumentException(sprintf('The start path "%s" is not absolute.', $startPath));
@@ -570,10 +568,8 @@ public function mirror(string $originDir, string $targetDir, \Traversable $itera
 
     /**
      * Returns whether the file path is an absolute path.
-     *
-     * @return bool
      */
-    public function isAbsolutePath(string $file)
+    public function isAbsolutePath(string $file): bool
     {
         return '' !== $file && (strspn($file, '/\\', 0, 1)
             || (\strlen($file) > 3 && ctype_alpha($file[0])
@@ -593,7 +589,7 @@ public function isAbsolutePath(string $file)
      *
      * @return string The new temporary filename (with path), or throw an exception on failure
      */
-    public function tempnam(string $dir, string $prefix/*, string $suffix = ''*/)
+    public function tempnam(string $dir, string $prefix/*, string $suffix = ''*/): string
     {
         $suffix = \func_num_args() > 2 ? func_get_arg(2) : '';
         [$scheme, $hierarchy] = $this->getSchemeAndHierarchy($dir);
diff --git a/src/Symfony/Component/HttpClient/HttpOptions.php b/src/Symfony/Component/HttpClient/HttpOptions.php
index 2034a5f284d82..8a5b5b217dc31 100644
--- a/src/Symfony/Component/HttpClient/HttpOptions.php
+++ b/src/Symfony/Component/HttpClient/HttpOptions.php
@@ -32,7 +32,7 @@ public function toArray(): array
     /**
      * @return $this
      */
-    public function setAuthBasic(string $user, string $password = '')
+    public function setAuthBasic(string $user, string $password = ''): static
     {
         $this->options['auth_basic'] = $user;
 
@@ -46,7 +46,7 @@ public function setAuthBasic(string $user, string $password = '')
     /**
      * @return $this
      */
-    public function setAuthBearer(string $token)
+    public function setAuthBearer(string $token): static
     {
         $this->options['auth_bearer'] = $token;
 
@@ -56,7 +56,7 @@ public function setAuthBearer(string $token)
     /**
      * @return $this
      */
-    public function setQuery(array $query)
+    public function setQuery(array $query): static
     {
         $this->options['query'] = $query;
 
@@ -66,7 +66,7 @@ public function setQuery(array $query)
     /**
      * @return $this
      */
-    public function setHeaders(iterable $headers)
+    public function setHeaders(iterable $headers): static
     {
         $this->options['headers'] = $headers;
 
@@ -78,7 +78,7 @@ public function setHeaders(iterable $headers)
      *
      * @return $this
      */
-    public function setBody(mixed $body)
+    public function setBody(mixed $body): static
     {
         $this->options['body'] = $body;
 
@@ -88,7 +88,7 @@ public function setBody(mixed $body)
     /**
      * @return $this
      */
-    public function setJson(mixed $json)
+    public function setJson(mixed $json): static
     {
         $this->options['json'] = $json;
 
@@ -98,7 +98,7 @@ public function setJson(mixed $json)
     /**
      * @return $this
      */
-    public function setUserData(mixed $data)
+    public function setUserData(mixed $data): static
     {
         $this->options['user_data'] = $data;
 
@@ -108,7 +108,7 @@ public function setUserData(mixed $data)
     /**
      * @return $this
      */
-    public function setMaxRedirects(int $max)
+    public function setMaxRedirects(int $max): static
     {
         $this->options['max_redirects'] = $max;
 
@@ -118,7 +118,7 @@ public function setMaxRedirects(int $max)
     /**
      * @return $this
      */
-    public function setHttpVersion(string $version)
+    public function setHttpVersion(string $version): static
     {
         $this->options['http_version'] = $version;
 
@@ -128,7 +128,7 @@ public function setHttpVersion(string $version)
     /**
      * @return $this
      */
-    public function setBaseUri(string $uri)
+    public function setBaseUri(string $uri): static
     {
         $this->options['base_uri'] = $uri;
 
@@ -138,7 +138,7 @@ public function setBaseUri(string $uri)
     /**
      * @return $this
      */
-    public function buffer(bool $buffer)
+    public function buffer(bool $buffer): static
     {
         $this->options['buffer'] = $buffer;
 
@@ -148,7 +148,7 @@ public function buffer(bool $buffer)
     /**
      * @return $this
      */
-    public function setOnProgress(callable $callback)
+    public function setOnProgress(callable $callback): static
     {
         $this->options['on_progress'] = $callback;
 
@@ -158,7 +158,7 @@ public function setOnProgress(callable $callback)
     /**
      * @return $this
      */
-    public function resolve(array $hostIps)
+    public function resolve(array $hostIps): static
     {
         $this->options['resolve'] = $hostIps;
 
@@ -168,7 +168,7 @@ public function resolve(array $hostIps)
     /**
      * @return $this
      */
-    public function setProxy(string $proxy)
+    public function setProxy(string $proxy): static
     {
         $this->options['proxy'] = $proxy;
 
@@ -178,7 +178,7 @@ public function setProxy(string $proxy)
     /**
      * @return $this
      */
-    public function setNoProxy(string $noProxy)
+    public function setNoProxy(string $noProxy): static
     {
         $this->options['no_proxy'] = $noProxy;
 
@@ -188,7 +188,7 @@ public function setNoProxy(string $noProxy)
     /**
      * @return $this
      */
-    public function setTimeout(float $timeout)
+    public function setTimeout(float $timeout): static
     {
         $this->options['timeout'] = $timeout;
 
@@ -198,7 +198,7 @@ public function setTimeout(float $timeout)
     /**
      * @return $this
      */
-    public function bindTo(string $bindto)
+    public function bindTo(string $bindto): static
     {
         $this->options['bindto'] = $bindto;
 
@@ -208,7 +208,7 @@ public function bindTo(string $bindto)
     /**
      * @return $this
      */
-    public function verifyPeer(bool $verify)
+    public function verifyPeer(bool $verify): static
     {
         $this->options['verify_peer'] = $verify;
 
@@ -218,7 +218,7 @@ public function verifyPeer(bool $verify)
     /**
      * @return $this
      */
-    public function verifyHost(bool $verify)
+    public function verifyHost(bool $verify): static
     {
         $this->options['verify_host'] = $verify;
 
@@ -228,7 +228,7 @@ public function verifyHost(bool $verify)
     /**
      * @return $this
      */
-    public function setCaFile(string $cafile)
+    public function setCaFile(string $cafile): static
     {
         $this->options['cafile'] = $cafile;
 
@@ -238,7 +238,7 @@ public function setCaFile(string $cafile)
     /**
      * @return $this
      */
-    public function setCaPath(string $capath)
+    public function setCaPath(string $capath): static
     {
         $this->options['capath'] = $capath;
 
@@ -248,7 +248,7 @@ public function setCaPath(string $capath)
     /**
      * @return $this
      */
-    public function setLocalCert(string $cert)
+    public function setLocalCert(string $cert): static
     {
         $this->options['local_cert'] = $cert;
 
@@ -258,7 +258,7 @@ public function setLocalCert(string $cert)
     /**
      * @return $this
      */
-    public function setLocalPk(string $pk)
+    public function setLocalPk(string $pk): static
     {
         $this->options['local_pk'] = $pk;
 
@@ -268,7 +268,7 @@ public function setLocalPk(string $pk)
     /**
      * @return $this
      */
-    public function setPassphrase(string $passphrase)
+    public function setPassphrase(string $passphrase): static
     {
         $this->options['passphrase'] = $passphrase;
 
@@ -278,7 +278,7 @@ public function setPassphrase(string $passphrase)
     /**
      * @return $this
      */
-    public function setCiphers(string $ciphers)
+    public function setCiphers(string $ciphers): static
     {
         $this->options['ciphers'] = $ciphers;
 
@@ -288,7 +288,7 @@ public function setCiphers(string $ciphers)
     /**
      * @return $this
      */
-    public function setPeerFingerprint(string|array $fingerprint)
+    public function setPeerFingerprint(string|array $fingerprint): static
     {
         $this->options['peer_fingerprint'] = $fingerprint;
 
@@ -298,7 +298,7 @@ public function setPeerFingerprint(string|array $fingerprint)
     /**
      * @return $this
      */
-    public function capturePeerCertChain(bool $capture)
+    public function capturePeerCertChain(bool $capture): static
     {
         $this->options['capture_peer_cert_chain'] = $capture;
 
@@ -308,7 +308,7 @@ public function capturePeerCertChain(bool $capture)
     /**
      * @return $this
      */
-    public function setExtra(string $name, mixed $value)
+    public function setExtra(string $name, mixed $value): static
     {
         $this->options['extra'][$name] = $value;
 
diff --git a/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleEntryReaderInterface.php b/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleEntryReaderInterface.php
index c4a0f565aa808..8858bf7f808c3 100644
--- a/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleEntryReaderInterface.php
+++ b/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleEntryReaderInterface.php
@@ -50,5 +50,5 @@ interface BundleEntryReaderInterface extends BundleReaderInterface
      *
      * @throws MissingResourceException If the indices cannot be accessed
      */
-    public function readEntry(string $path, string $locale, array $indices, bool $fallback = true);
+    public function readEntry(string $path, string $locale, array $indices, bool $fallback = true): mixed;
 }
diff --git a/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleReaderInterface.php b/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleReaderInterface.php
index 545be464c88f8..737b44d9df1d0 100644
--- a/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleReaderInterface.php
+++ b/src/Symfony/Component/Intl/Data/Bundle/Reader/BundleReaderInterface.php
@@ -24,5 +24,5 @@ interface BundleReaderInterface
      * @return mixed returns an array or {@link \ArrayAccess} instance for
      *               complex data, a scalar value otherwise
      */
-    public function read(string $path, string $locale);
+    public function read(string $path, string $locale): mixed;
 }
diff --git a/src/Symfony/Component/Intl/Util/IcuVersion.php b/src/Symfony/Component/Intl/Util/IcuVersion.php
index 3b1d7486e8fcb..5ad76544a585a 100644
--- a/src/Symfony/Component/Intl/Util/IcuVersion.php
+++ b/src/Symfony/Component/Intl/Util/IcuVersion.php
@@ -50,7 +50,7 @@ class IcuVersion
      *
      * @see normalize()
      */
-    public static function compare(string $version1, string $version2, string $operator, int $precision = null)
+    public static function compare(string $version1, string $version2, string $operator, int $precision = null): bool
     {
         $version1 = self::normalize($version1, $precision);
         $version2 = self::normalize($version2, $precision);
@@ -83,7 +83,7 @@ public static function compare(string $version1, string $version2, string $opera
      * @return string|null the normalized ICU version or NULL if it couldn't be
      *                     normalized
      */
-    public static function normalize(string $version, ?int $precision)
+    public static function normalize(string $version, ?int $precision): ?string
     {
         $version = preg_replace('/^(\d)\.(\d)/', '$1$2', $version);
 
diff --git a/src/Symfony/Component/Intl/Util/Version.php b/src/Symfony/Component/Intl/Util/Version.php
index 4b74e09022db3..f045853a5323b 100644
--- a/src/Symfony/Component/Intl/Util/Version.php
+++ b/src/Symfony/Component/Intl/Util/Version.php
@@ -40,7 +40,7 @@ class Version
      *
      * @see normalize()
      */
-    public static function compare(string $version1, string $version2, string $operator, int $precision = null)
+    public static function compare(string $version1, string $version2, string $operator, int $precision = null): bool
     {
         $version1 = self::normalize($version1, $precision);
         $version2 = self::normalize($version2, $precision);
@@ -66,7 +66,7 @@ public static function compare(string $version1, string $version2, string $opera
      * @return string|null the normalized version or NULL if it couldn't be
      *                     normalized
      */
-    public static function normalize(string $version, ?int $precision)
+    public static function normalize(string $version, ?int $precision): ?string
     {
         if (null === $precision) {
             return $version;
diff --git a/src/Symfony/Component/Lock/LockInterface.php b/src/Symfony/Component/Lock/LockInterface.php
index 40b75244b31ed..383469e732438 100644
--- a/src/Symfony/Component/Lock/LockInterface.php
+++ b/src/Symfony/Component/Lock/LockInterface.php
@@ -31,7 +31,7 @@ interface LockInterface
      * @throws LockConflictedException If the lock is acquired by someone else in blocking mode
      * @throws LockAcquiringException  If the lock can not be acquired
      */
-    public function acquire(bool $blocking = false);
+    public function acquire(bool $blocking = false): bool;
 
     /**
      * Increase the duration of an acquired lock.
@@ -48,7 +48,7 @@ public function refresh(float $ttl = null);
      *
      * @return bool
      */
-    public function isAcquired();
+    public function isAcquired(): bool;
 
     /**
      * Release the lock.
@@ -60,12 +60,12 @@ public function release();
     /**
      * @return bool
      */
-    public function isExpired();
+    public function isExpired(): bool;
 
     /**
      * Returns the remaining lifetime.
      *
      * @return float|null Remaining lifetime in seconds. Null when the lock won't expire.
      */
-    public function getRemainingLifetime();
+    public function getRemainingLifetime(): ?float;
 }
diff --git a/src/Symfony/Component/Lock/PersistingStoreInterface.php b/src/Symfony/Component/Lock/PersistingStoreInterface.php
index 03309a90b5662..50a5ee0e23298 100644
--- a/src/Symfony/Component/Lock/PersistingStoreInterface.php
+++ b/src/Symfony/Component/Lock/PersistingStoreInterface.php
@@ -40,7 +40,7 @@ public function delete(Key $key);
      *
      * @return bool
      */
-    public function exists(Key $key);
+    public function exists(Key $key): bool;
 
     /**
      * Extends the TTL of a resource.
diff --git a/src/Symfony/Component/Lock/SharedLockInterface.php b/src/Symfony/Component/Lock/SharedLockInterface.php
index 62cedc5cd014a..38d1cf07fcb28 100644
--- a/src/Symfony/Component/Lock/SharedLockInterface.php
+++ b/src/Symfony/Component/Lock/SharedLockInterface.php
@@ -30,5 +30,5 @@ interface SharedLockInterface extends LockInterface
      * @throws LockConflictedException If the lock is acquired by someone else in blocking mode
      * @throws LockAcquiringException  If the lock can not be acquired
      */
-    public function acquireRead(bool $blocking = false);
+    public function acquireRead(bool $blocking = false): bool;
 }
diff --git a/src/Symfony/Component/Lock/Store/CombinedStore.php b/src/Symfony/Component/Lock/Store/CombinedStore.php
index 8d0526b088466..0ca6707067ef5 100644
--- a/src/Symfony/Component/Lock/Store/CombinedStore.php
+++ b/src/Symfony/Component/Lock/Store/CombinedStore.php
@@ -192,7 +192,7 @@ public function delete(Key $key)
     /**
      * {@inheritdoc}
      */
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         $successCount = 0;
         $failureCount = 0;
diff --git a/src/Symfony/Component/Lock/Store/FlockStore.php b/src/Symfony/Component/Lock/Store/FlockStore.php
index a5c24183b7aa1..724ec44c9c25f 100644
--- a/src/Symfony/Component/Lock/Store/FlockStore.php
+++ b/src/Symfony/Component/Lock/Store/FlockStore.php
@@ -161,7 +161,7 @@ public function delete(Key $key)
     /**
      * {@inheritdoc}
      */
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         return $key->hasState(__CLASS__);
     }
diff --git a/src/Symfony/Component/Lock/Store/InMemoryStore.php b/src/Symfony/Component/Lock/Store/InMemoryStore.php
index 8b1dc1c7ce493..6842abea76aa3 100644
--- a/src/Symfony/Component/Lock/Store/InMemoryStore.php
+++ b/src/Symfony/Component/Lock/Store/InMemoryStore.php
@@ -94,7 +94,7 @@ public function delete(Key $key)
         }
     }
 
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         $hashKey = (string) $key;
         $token = $this->getUniqueToken($key);
diff --git a/src/Symfony/Component/Lock/Store/MemcachedStore.php b/src/Symfony/Component/Lock/Store/MemcachedStore.php
index e844a35bb6cfc..6f37ab1c4e16c 100644
--- a/src/Symfony/Component/Lock/Store/MemcachedStore.php
+++ b/src/Symfony/Component/Lock/Store/MemcachedStore.php
@@ -134,7 +134,7 @@ public function delete(Key $key)
     /**
      * {@inheritdoc}
      */
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         return $this->memcached->get((string) $key) === $this->getUniqueToken($key);
     }
diff --git a/src/Symfony/Component/Lock/Store/PdoStore.php b/src/Symfony/Component/Lock/Store/PdoStore.php
index f938e1e808f2c..4550144051848 100644
--- a/src/Symfony/Component/Lock/Store/PdoStore.php
+++ b/src/Symfony/Component/Lock/Store/PdoStore.php
@@ -200,7 +200,7 @@ public function delete(Key $key)
     /**
      * {@inheritdoc}
      */
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         $sql = "SELECT 1 FROM $this->table WHERE $this->idCol = :id AND $this->tokenCol = :token AND $this->expirationCol > {$this->getCurrentTimestampStatement()}";
         $stmt = $this->getConnection()->prepare($sql);
diff --git a/src/Symfony/Component/Lock/Store/PostgreSqlStore.php b/src/Symfony/Component/Lock/Store/PostgreSqlStore.php
index 8db769873a196..575d574bda82e 100644
--- a/src/Symfony/Component/Lock/Store/PostgreSqlStore.php
+++ b/src/Symfony/Component/Lock/Store/PostgreSqlStore.php
@@ -148,7 +148,7 @@ public function delete(Key $key)
         $store->delete($key);
     }
 
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         $sql = "SELECT count(*) FROM pg_locks WHERE locktype='advisory' AND objid=:key AND pid=pg_backend_pid()";
         $stmt = $this->getConnection()->prepare($sql);
diff --git a/src/Symfony/Component/Lock/Store/RedisStore.php b/src/Symfony/Component/Lock/Store/RedisStore.php
index 5f596fac09741..633ab1f21a6c2 100644
--- a/src/Symfony/Component/Lock/Store/RedisStore.php
+++ b/src/Symfony/Component/Lock/Store/RedisStore.php
@@ -218,7 +218,7 @@ public function delete(Key $key)
     /**
      * {@inheritdoc}
      */
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         $script = '
             local key = KEYS[1]
diff --git a/src/Symfony/Component/Lock/Store/SemaphoreStore.php b/src/Symfony/Component/Lock/Store/SemaphoreStore.php
index 88c7a22174c57..7b8caf3a7910c 100644
--- a/src/Symfony/Component/Lock/Store/SemaphoreStore.php
+++ b/src/Symfony/Component/Lock/Store/SemaphoreStore.php
@@ -107,7 +107,7 @@ public function putOffExpiration(Key $key, float $ttl)
     /**
      * {@inheritdoc}
      */
-    public function exists(Key $key)
+    public function exists(Key $key): bool
     {
         return $key->hasState(__CLASS__);
     }
diff --git a/src/Symfony/Component/Lock/Store/StoreFactory.php b/src/Symfony/Component/Lock/Store/StoreFactory.php
index 57e88daa8df7d..545800944842e 100644
--- a/src/Symfony/Component/Lock/Store/StoreFactory.php
+++ b/src/Symfony/Component/Lock/Store/StoreFactory.php
@@ -28,7 +28,7 @@ class StoreFactory
     /**
      * @return PersistingStoreInterface
      */
-    public static function createStore(object|string $connection)
+    public static function createStore(object|string $connection): PersistingStoreInterface
     {
         switch (true) {
             case $connection instanceof \Redis:
diff --git a/src/Symfony/Component/Lock/Strategy/ConsensusStrategy.php b/src/Symfony/Component/Lock/Strategy/ConsensusStrategy.php
index 1338b10dd63f4..7c3508aa999d7 100644
--- a/src/Symfony/Component/Lock/Strategy/ConsensusStrategy.php
+++ b/src/Symfony/Component/Lock/Strategy/ConsensusStrategy.php
@@ -21,7 +21,7 @@ class ConsensusStrategy implements StrategyInterface
     /**
      * {@inheritdoc}
      */
-    public function isMet(int $numberOfSuccess, int $numberOfItems)
+    public function isMet(int $numberOfSuccess, int $numberOfItems): bool
     {
         return $numberOfSuccess > ($numberOfItems / 2);
     }
@@ -29,7 +29,7 @@ public function isMet(int $numberOfSuccess, int $numberOfItems)
     /**
      * {@inheritdoc}
      */
-    public function canBeMet(int $numberOfFailure, int $numberOfItems)
+    public function canBeMet(int $numberOfFailure, int $numberOfItems): bool
     {
         return $numberOfFailure < ($numberOfItems / 2);
     }
diff --git a/src/Symfony/Component/Lock/Strategy/StrategyInterface.php b/src/Symfony/Component/Lock/Strategy/StrategyInterface.php
index 7c5f9d8cdfc7a..be3aeeba3c758 100644
--- a/src/Symfony/Component/Lock/Strategy/StrategyInterface.php
+++ b/src/Symfony/Component/Lock/Strategy/StrategyInterface.php
@@ -23,7 +23,7 @@ interface StrategyInterface
      *
      * @return bool
      */
-    public function isMet(int $numberOfSuccess, int $numberOfItems);
+    public function isMet(int $numberOfSuccess, int $numberOfItems): bool;
 
     /**
      * Returns whether or not the quorum *could* be met.
@@ -33,5 +33,5 @@ public function isMet(int $numberOfSuccess, int $numberOfItems);
      *
      * @return bool
      */
-    public function canBeMet(int $numberOfFailure, int $numberOfItems);
+    public function canBeMet(int $numberOfFailure, int $numberOfItems): bool;
 }
diff --git a/src/Symfony/Component/Lock/Strategy/UnanimousStrategy.php b/src/Symfony/Component/Lock/Strategy/UnanimousStrategy.php
index 63f9d1b4a1b2a..2a2c4ab014fb8 100644
--- a/src/Symfony/Component/Lock/Strategy/UnanimousStrategy.php
+++ b/src/Symfony/Component/Lock/Strategy/UnanimousStrategy.php
@@ -21,7 +21,7 @@ class UnanimousStrategy implements StrategyInterface
     /**
      * {@inheritdoc}
      */
-    public function isMet(int $numberOfSuccess, int $numberOfItems)
+    public function isMet(int $numberOfSuccess, int $numberOfItems): bool
     {
         return $numberOfSuccess === $numberOfItems;
     }
@@ -29,7 +29,7 @@ public function isMet(int $numberOfSuccess, int $numberOfItems)
     /**
      * {@inheritdoc}
      */
-    public function canBeMet(int $numberOfFailure, int $numberOfItems)
+    public function canBeMet(int $numberOfFailure, int $numberOfItems): bool
     {
         return 0 === $numberOfFailure;
     }
diff --git a/src/Symfony/Component/Runtime/GenericRuntime.php b/src/Symfony/Component/Runtime/GenericRuntime.php
index e9484f755e3c6..dbfd1e23b0e1a 100644
--- a/src/Symfony/Component/Runtime/GenericRuntime.php
+++ b/src/Symfony/Component/Runtime/GenericRuntime.php
@@ -147,7 +147,7 @@ public function getRunner(?object $application): RunnerInterface
     /**
      * @return mixed
      */
-    protected function getArgument(\ReflectionParameter $parameter, ?string $type)
+    protected function getArgument(\ReflectionParameter $parameter, ?string $type): mixed
     {
         if ('array' === $type) {
             switch ($parameter->name) {
diff --git a/src/Symfony/Component/Runtime/SymfonyRuntime.php b/src/Symfony/Component/Runtime/SymfonyRuntime.php
index 9df2f5ca4b7b3..a6c576d495c1c 100644
--- a/src/Symfony/Component/Runtime/SymfonyRuntime.php
+++ b/src/Symfony/Component/Runtime/SymfonyRuntime.php
@@ -158,7 +158,7 @@ public function getRunner(?object $application): RunnerInterface
     /**
      * @return mixed
      */
-    protected function getArgument(\ReflectionParameter $parameter, ?string $type)
+    protected function getArgument(\ReflectionParameter $parameter, ?string $type): mixed
     {
         switch ($type) {
             case Request::class:
diff --git a/src/Symfony/Component/Stopwatch/Section.php b/src/Symfony/Component/Stopwatch/Section.php
index b3ab3a1b2769c..e25eb1abe41ca 100644
--- a/src/Symfony/Component/Stopwatch/Section.php
+++ b/src/Symfony/Component/Stopwatch/Section.php
@@ -47,7 +47,7 @@ public function __construct(float $origin = null, bool $morePrecision = false)
      *
      * @return self|null The child section or null when none found
      */
-    public function get(string $id)
+    public function get(string $id): ?self
     {
         foreach ($this->children as $child) {
             if ($id === $child->getId()) {
@@ -65,7 +65,7 @@ public function get(string $id)
      *
      * @return self
      */
-    public function open(?string $id)
+    public function open(?string $id): self
     {
         if (null === $id || null === $session = $this->get($id)) {
             $session = $this->children[] = new self(microtime(true) * 1000, $this->morePrecision);
@@ -77,7 +77,7 @@ public function open(?string $id)
     /**
      * @return string|null The identifier of the section
      */
-    public function getId()
+    public function getId(): ?string
     {
         return $this->id;
     }
@@ -87,7 +87,7 @@ public function getId()
      *
      * @return $this
      */
-    public function setId(string $id)
+    public function setId(string $id): static
     {
         $this->id = $id;
 
@@ -99,7 +99,7 @@ public function setId(string $id)
      *
      * @return StopwatchEvent The event
      */
-    public function startEvent(string $name, ?string $category)
+    public function startEvent(string $name, ?string $category): StopwatchEvent
     {
         if (!isset($this->events[$name])) {
             $this->events[$name] = new StopwatchEvent($this->origin ?: microtime(true) * 1000, $category, $this->morePrecision, $name);
@@ -113,7 +113,7 @@ public function startEvent(string $name, ?string $category)
      *
      * @return bool
      */
-    public function isEventStarted(string $name)
+    public function isEventStarted(string $name): bool
     {
         return isset($this->events[$name]) && $this->events[$name]->isStarted();
     }
@@ -125,7 +125,7 @@ public function isEventStarted(string $name)
      *
      * @throws \LogicException When the event has not been started
      */
-    public function stopEvent(string $name)
+    public function stopEvent(string $name): StopwatchEvent
     {
         if (!isset($this->events[$name])) {
             throw new \LogicException(sprintf('Event "%s" is not started.', $name));
@@ -141,7 +141,7 @@ public function stopEvent(string $name)
      *
      * @throws \LogicException When the event has not been started
      */
-    public function lap(string $name)
+    public function lap(string $name): StopwatchEvent
     {
         return $this->stopEvent($name)->start();
     }
@@ -153,7 +153,7 @@ public function lap(string $name)
      *
      * @throws \LogicException When the event is not known
      */
-    public function getEvent(string $name)
+    public function getEvent(string $name): StopwatchEvent
     {
         if (!isset($this->events[$name])) {
             throw new \LogicException(sprintf('Event "%s" is not known.', $name));
@@ -167,7 +167,7 @@ public function getEvent(string $name)
      *
      * @return StopwatchEvent[]
      */
-    public function getEvents()
+    public function getEvents(): array
     {
         return $this->events;
     }
diff --git a/src/Symfony/Component/Stopwatch/Stopwatch.php b/src/Symfony/Component/Stopwatch/Stopwatch.php
index d42e5bce3a82e..89b6a941926fe 100644
--- a/src/Symfony/Component/Stopwatch/Stopwatch.php
+++ b/src/Symfony/Component/Stopwatch/Stopwatch.php
@@ -47,7 +47,7 @@ public function __construct(bool $morePrecision = false)
     /**
      * @return Section[]
      */
-    public function getSections()
+    public function getSections(): array
     {
         return $this->sections;
     }
@@ -98,7 +98,7 @@ public function stopSection(string $id)
      *
      * @return StopwatchEvent
      */
-    public function start(string $name, string $category = null)
+    public function start(string $name, string $category = null): StopwatchEvent
     {
         return end($this->activeSections)->startEvent($name, $category);
     }
@@ -108,7 +108,7 @@ public function start(string $name, string $category = null)
      *
      * @return bool
      */
-    public function isStarted(string $name)
+    public function isStarted(string $name): bool
     {
         return end($this->activeSections)->isEventStarted($name);
     }
@@ -118,7 +118,7 @@ public function isStarted(string $name)
      *
      * @return StopwatchEvent
      */
-    public function stop(string $name)
+    public function stop(string $name): StopwatchEvent
     {
         return end($this->activeSections)->stopEvent($name);
     }
@@ -128,7 +128,7 @@ public function stop(string $name)
      *
      * @return StopwatchEvent
      */
-    public function lap(string $name)
+    public function lap(string $name): StopwatchEvent
     {
         return end($this->activeSections)->stopEvent($name)->start();
     }
@@ -138,7 +138,7 @@ public function lap(string $name)
      *
      * @return StopwatchEvent
      */
-    public function getEvent(string $name)
+    public function getEvent(string $name): StopwatchEvent
     {
         return end($this->activeSections)->getEvent($name);
     }
@@ -148,7 +148,7 @@ public function getEvent(string $name)
      *
      * @return StopwatchEvent[]
      */
-    public function getSectionEvents(string $id)
+    public function getSectionEvents(string $id): array
     {
         return isset($this->sections[$id]) ? $this->sections[$id]->getEvents() : [];
     }
diff --git a/src/Symfony/Component/Stopwatch/StopwatchEvent.php b/src/Symfony/Component/Stopwatch/StopwatchEvent.php
index 81985bb78cf37..e512a94329b16 100644
--- a/src/Symfony/Component/Stopwatch/StopwatchEvent.php
+++ b/src/Symfony/Component/Stopwatch/StopwatchEvent.php
@@ -55,7 +55,7 @@ public function __construct(float $origin, string $category = null, bool $morePr
      *
      * @return string The category
      */
-    public function getCategory()
+    public function getCategory(): string
     {
         return $this->category;
     }
@@ -65,7 +65,7 @@ public function getCategory()
      *
      * @return float The origin in milliseconds
      */
-    public function getOrigin()
+    public function getOrigin(): float
     {
         return $this->origin;
     }
@@ -75,7 +75,7 @@ public function getOrigin()
      *
      * @return $this
      */
-    public function start()
+    public function start(): static
     {
         $this->started[] = $this->getNow();
 
@@ -89,7 +89,7 @@ public function start()
      *
      * @throws \LogicException When stop() is called without a matching call to start()
      */
-    public function stop()
+    public function stop(): static
     {
         if (!\count($this->started)) {
             throw new \LogicException('stop() called but start() has not been called before.');
@@ -105,7 +105,7 @@ public function stop()
      *
      * @return bool
      */
-    public function isStarted()
+    public function isStarted(): bool
     {
         return !empty($this->started);
     }
@@ -115,7 +115,7 @@ public function isStarted()
      *
      * @return $this
      */
-    public function lap()
+    public function lap(): static
     {
         return $this->stop()->start();
     }
@@ -135,7 +135,7 @@ public function ensureStopped()
      *
      * @return StopwatchPeriod[]
      */
-    public function getPeriods()
+    public function getPeriods(): array
     {
         return $this->periods;
     }
@@ -145,7 +145,7 @@ public function getPeriods()
      *
      * @return int|float The time (in milliseconds)
      */
-    public function getStartTime()
+    public function getStartTime(): int|float
     {
         if (isset($this->periods[0])) {
             return $this->periods[0]->getStartTime();
@@ -163,7 +163,7 @@ public function getStartTime()
      *
      * @return int|float The time (in milliseconds)
      */
-    public function getEndTime()
+    public function getEndTime(): int|float
     {
         $count = \count($this->periods);
 
@@ -175,7 +175,7 @@ public function getEndTime()
      *
      * @return int|float The duration (in milliseconds)
      */
-    public function getDuration()
+    public function getDuration(): int|float
     {
         $periods = $this->periods;
         $left = \count($this->started);
@@ -197,7 +197,7 @@ public function getDuration()
      *
      * @return int The memory usage (in bytes)
      */
-    public function getMemory()
+    public function getMemory(): int
     {
         $memory = 0;
         foreach ($this->periods as $period) {
@@ -214,7 +214,7 @@ public function getMemory()
      *
      * @return float Time in ms
      */
-    protected function getNow()
+    protected function getNow(): float
     {
         return $this->formatTime(microtime(true) * 1000 - $this->origin);
     }
diff --git a/src/Symfony/Component/Stopwatch/StopwatchPeriod.php b/src/Symfony/Component/Stopwatch/StopwatchPeriod.php
index adf4da977e6ad..b2492f94109f5 100644
--- a/src/Symfony/Component/Stopwatch/StopwatchPeriod.php
+++ b/src/Symfony/Component/Stopwatch/StopwatchPeriod.php
@@ -39,7 +39,7 @@ public function __construct(int|float $start, int|float $end, bool $morePrecisio
      *
      * @return int|float The time (in milliseconds)
      */
-    public function getStartTime()
+    public function getStartTime(): int|float
     {
         return $this->start;
     }
@@ -49,7 +49,7 @@ public function getStartTime()
      *
      * @return int|float The time (in milliseconds)
      */
-    public function getEndTime()
+    public function getEndTime(): int|float
     {
         return $this->end;
     }
@@ -59,7 +59,7 @@ public function getEndTime()
      *
      * @return int|float The period duration (in milliseconds)
      */
-    public function getDuration()
+    public function getDuration(): int|float
     {
         return $this->end - $this->start;
     }
@@ -69,7 +69,7 @@ public function getDuration()
      *
      * @return int The memory usage (in bytes)
      */
-    public function getMemory()
+    public function getMemory(): int
     {
         return $this->memory;
     }
diff --git a/src/Symfony/Component/String/AbstractString.php b/src/Symfony/Component/String/AbstractString.php
index 62a4f89200c63..71a981e7d466e 100644
--- a/src/Symfony/Component/String/AbstractString.php
+++ b/src/Symfony/Component/String/AbstractString.php
@@ -95,7 +95,7 @@ public static function wrap(array $values): array
      *
      * @return static
      */
-    public function after(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): self
+    public function after(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): static
     {
         $str = clone $this;
         $i = \PHP_INT_MAX;
@@ -130,7 +130,7 @@ public function after(string|iterable $needle, bool $includeNeedle = false, int
      *
      * @return static
      */
-    public function afterLast(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): self
+    public function afterLast(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): static
     {
         $str = clone $this;
         $i = null;
@@ -163,14 +163,14 @@ public function afterLast(string|iterable $needle, bool $includeNeedle = false,
     /**
      * @return static
      */
-    abstract public function append(string ...$suffix): self;
+    abstract public function append(string ...$suffix): static;
 
     /**
      * @param string|string[] $needle
      *
      * @return static
      */
-    public function before(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): self
+    public function before(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): static
     {
         $str = clone $this;
         $i = \PHP_INT_MAX;
@@ -205,7 +205,7 @@ public function before(string|iterable $needle, bool $includeNeedle = false, int
      *
      * @return static
      */
-    public function beforeLast(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): self
+    public function beforeLast(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): static
     {
         $str = clone $this;
         $i = null;
@@ -248,7 +248,7 @@ public function bytesAt(int $offset): array
     /**
      * @return static
      */
-    abstract public function camel(): self;
+    abstract public function camel(): static;
 
     /**
      * @return static[]
@@ -258,7 +258,7 @@ abstract public function chunk(int $length = 1): array;
     /**
      * @return static
      */
-    public function collapseWhitespace(): self
+    public function collapseWhitespace(): static
     {
         $str = clone $this;
         $str->string = trim(preg_replace('/(?:\s{2,}+|[^\S ])/', ' ', $str->string));
@@ -295,7 +295,7 @@ public function endsWith(string|iterable $suffix): bool
     /**
      * @return static
      */
-    public function ensureEnd(string $suffix): self
+    public function ensureEnd(string $suffix): static
     {
         if (!$this->endsWith($suffix)) {
             return $this->append($suffix);
@@ -310,7 +310,7 @@ public function ensureEnd(string $suffix): self
     /**
      * @return static
      */
-    public function ensureStart(string $prefix): self
+    public function ensureStart(string $prefix): static
     {
         $prefix = new static($prefix);
 
@@ -350,12 +350,12 @@ public function equalsTo(string|iterable $string): bool
     /**
      * @return static
      */
-    abstract public function folded(): self;
+    abstract public function folded(): static;
 
     /**
      * @return static
      */
-    public function ignoreCase(): self
+    public function ignoreCase(): static
     {
         $str = clone $this;
         $str->ignoreCase = true;
@@ -415,7 +415,7 @@ public function isEmpty(): bool
     /**
      * @return static
      */
-    abstract public function join(array $strings, string $lastGlue = null): self;
+    abstract public function join(array $strings, string $lastGlue = null): static;
 
     public function jsonSerialize(): string
     {
@@ -427,7 +427,7 @@ abstract public function length(): int;
     /**
      * @return static
      */
-    abstract public function lower(): self;
+    abstract public function lower(): static;
 
     /**
      * Matches the string using a regular expression.
@@ -441,27 +441,27 @@ abstract public function match(string $regexp, int $flags = 0, int $offset = 0):
     /**
      * @return static
      */
-    abstract public function padBoth(int $length, string $padStr = ' '): self;
+    abstract public function padBoth(int $length, string $padStr = ' '): static;
 
     /**
      * @return static
      */
-    abstract public function padEnd(int $length, string $padStr = ' '): self;
+    abstract public function padEnd(int $length, string $padStr = ' '): static;
 
     /**
      * @return static
      */
-    abstract public function padStart(int $length, string $padStr = ' '): self;
+    abstract public function padStart(int $length, string $padStr = ' '): static;
 
     /**
      * @return static
      */
-    abstract public function prepend(string ...$prefix): self;
+    abstract public function prepend(string ...$prefix): static;
 
     /**
      * @return static
      */
-    public function repeat(int $multiplier): self
+    public function repeat(int $multiplier): static
     {
         if (0 > $multiplier) {
             throw new InvalidArgumentException(sprintf('Multiplier must be positive, %d given.', $multiplier));
@@ -476,34 +476,34 @@ public function repeat(int $multiplier): self
     /**
      * @return static
      */
-    abstract public function replace(string $from, string $to): self;
+    abstract public function replace(string $from, string $to): static;
 
     /**
      * @param string|callable $to
      *
      * @return static
      */
-    abstract public function replaceMatches(string $fromRegexp, string|callable $to): self;
+    abstract public function replaceMatches(string $fromRegexp, string|callable $to): static;
 
     /**
      * @return static
      */
-    abstract public function reverse(): self;
+    abstract public function reverse(): static;
 
     /**
      * @return static
      */
-    abstract public function slice(int $start = 0, int $length = null): self;
+    abstract public function slice(int $start = 0, int $length = null): static;
 
     /**
      * @return static
      */
-    abstract public function snake(): self;
+    abstract public function snake(): static;
 
     /**
      * @return static
      */
-    abstract public function splice(string $replacement, int $start = 0, int $length = null): self;
+    abstract public function splice(string $replacement, int $start = 0, int $length = null): static;
 
     /**
      * @return static[]
@@ -574,7 +574,7 @@ public function startsWith(string|iterable $prefix): bool
     /**
      * @return static
      */
-    abstract public function title(bool $allWords = false): self;
+    abstract public function title(bool $allWords = false): static;
 
     public function toByteString(string $toEncoding = null): ByteString
     {
@@ -625,22 +625,22 @@ public function toUnicodeString(): UnicodeString
     /**
      * @return static
      */
-    abstract public function trim(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): self;
+    abstract public function trim(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): static;
 
     /**
      * @return static
      */
-    abstract public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): self;
+    abstract public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): static;
 
     /**
      * @return static
      */
-    abstract public function trimStart(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): self;
+    abstract public function trimStart(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): static;
 
     /**
      * @return static
      */
-    public function truncate(int $length, string $ellipsis = '', bool $cut = true): self
+    public function truncate(int $length, string $ellipsis = '', bool $cut = true): static
     {
         $stringLength = $this->length();
 
@@ -670,7 +670,7 @@ public function truncate(int $length, string $ellipsis = '', bool $cut = true):
     /**
      * @return static
      */
-    abstract public function upper(): self;
+    abstract public function upper(): static;
 
     /**
      * Returns the printable length on a terminal.
@@ -680,7 +680,7 @@ abstract public function width(bool $ignoreAnsiDecoration = true): int;
     /**
      * @return static
      */
-    public function wordwrap(int $width = 75, string $break = "\n", bool $cut = false): self
+    public function wordwrap(int $width = 75, string $break = "\n", bool $cut = false): static
     {
         $lines = '' !== $break ? $this->split($break) : [clone $this];
         $chars = [];
diff --git a/src/Symfony/Component/String/AbstractUnicodeString.php b/src/Symfony/Component/String/AbstractUnicodeString.php
index ecb53481b4e35..dc85c67ce2eae 100644
--- a/src/Symfony/Component/String/AbstractUnicodeString.php
+++ b/src/Symfony/Component/String/AbstractUnicodeString.php
@@ -53,7 +53,7 @@ abstract class AbstractUnicodeString extends AbstractString
     /**
      * @return static
      */
-    public static function fromCodePoints(int ...$codes): self
+    public static function fromCodePoints(int ...$codes): static
     {
         $string = '';
 
@@ -157,7 +157,7 @@ public function ascii(array $rules = []): self
         return $str;
     }
 
-    public function camel(): parent
+    public function camel(): static
     {
         $str = clone $this;
         $str->string = str_replace(' ', '', preg_replace_callback('/\b./u', static function ($m) use (&$i) {
@@ -187,7 +187,7 @@ public function codePointsAt(int $offset): array
         return $codePoints;
     }
 
-    public function folded(bool $compat = true): parent
+    public function folded(bool $compat = true): static
     {
         $str = clone $this;
 
@@ -201,7 +201,7 @@ public function folded(bool $compat = true): parent
         return $str;
     }
 
-    public function join(array $strings, string $lastGlue = null): parent
+    public function join(array $strings, string $lastGlue = null): static
     {
         $str = clone $this;
 
@@ -215,7 +215,7 @@ public function join(array $strings, string $lastGlue = null): parent
         return $str;
     }
 
-    public function lower(): parent
+    public function lower(): static
     {
         $str = clone $this;
         $str->string = mb_strtolower(str_replace('İ', 'i̇', $str->string), 'UTF-8');
@@ -255,7 +255,7 @@ public function match(string $regexp, int $flags = 0, int $offset = 0): array
     /**
      * @return static
      */
-    public function normalize(int $form = self::NFC): self
+    public function normalize(int $form = self::NFC): static
     {
         if (!\in_array($form, [self::NFC, self::NFD, self::NFKC, self::NFKD])) {
             throw new InvalidArgumentException('Unsupported normalization form.');
@@ -267,7 +267,7 @@ public function normalize(int $form = self::NFC): self
         return $str;
     }
 
-    public function padBoth(int $length, string $padStr = ' '): parent
+    public function padBoth(int $length, string $padStr = ' '): static
     {
         if ('' === $padStr || !preg_match('//u', $padStr)) {
             throw new InvalidArgumentException('Invalid UTF-8 string.');
@@ -279,7 +279,7 @@ public function padBoth(int $length, string $padStr = ' '): parent
         return $this->pad($length, $pad, \STR_PAD_BOTH);
     }
 
-    public function padEnd(int $length, string $padStr = ' '): parent
+    public function padEnd(int $length, string $padStr = ' '): static
     {
         if ('' === $padStr || !preg_match('//u', $padStr)) {
             throw new InvalidArgumentException('Invalid UTF-8 string.');
@@ -291,7 +291,7 @@ public function padEnd(int $length, string $padStr = ' '): parent
         return $this->pad($length, $pad, \STR_PAD_RIGHT);
     }
 
-    public function padStart(int $length, string $padStr = ' '): parent
+    public function padStart(int $length, string $padStr = ' '): static
     {
         if ('' === $padStr || !preg_match('//u', $padStr)) {
             throw new InvalidArgumentException('Invalid UTF-8 string.');
@@ -303,7 +303,7 @@ public function padStart(int $length, string $padStr = ' '): parent
         return $this->pad($length, $pad, \STR_PAD_LEFT);
     }
 
-    public function replaceMatches(string $fromRegexp, string|callable $to): parent
+    public function replaceMatches(string $fromRegexp, string|callable $to): static
     {
         if ($this->ignoreCase) {
             $fromRegexp .= 'i';
@@ -354,7 +354,7 @@ public function replaceMatches(string $fromRegexp, string|callable $to): parent
         return $str;
     }
 
-    public function reverse(): parent
+    public function reverse(): static
     {
         $str = clone $this;
         $str->string = implode('', array_reverse(preg_split('/(\X)/u', $str->string, -1, \PREG_SPLIT_DELIM_CAPTURE | \PREG_SPLIT_NO_EMPTY)));
@@ -362,7 +362,7 @@ public function reverse(): parent
         return $str;
     }
 
-    public function snake(): parent
+    public function snake(): static
     {
         $str = $this->camel()->title();
         $str->string = mb_strtolower(preg_replace(['/(\p{Lu}+)(\p{Lu}\p{Ll})/u', '/([\p{Ll}0-9])(\p{Lu})/u'], '\1_\2', $str->string), 'UTF-8');
@@ -370,7 +370,7 @@ public function snake(): parent
         return $str;
     }
 
-    public function title(bool $allWords = false): parent
+    public function title(bool $allWords = false): static
     {
         $str = clone $this;
 
@@ -383,7 +383,7 @@ public function title(bool $allWords = false): parent
         return $str;
     }
 
-    public function trim(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): parent
+    public function trim(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): static
     {
         if (" \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}" !== $chars && !preg_match('//u', $chars)) {
             throw new InvalidArgumentException('Invalid UTF-8 chars.');
@@ -396,7 +396,7 @@ public function trim(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): parent
         return $str;
     }
 
-    public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): parent
+    public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): static
     {
         if (" \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}" !== $chars && !preg_match('//u', $chars)) {
             throw new InvalidArgumentException('Invalid UTF-8 chars.');
@@ -409,7 +409,7 @@ public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): pare
         return $str;
     }
 
-    public function trimStart(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): parent
+    public function trimStart(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): static
     {
         if (" \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}" !== $chars && !preg_match('//u', $chars)) {
             throw new InvalidArgumentException('Invalid UTF-8 chars.');
@@ -422,7 +422,7 @@ public function trimStart(string $chars = " \t\n\r\0\x0B\x0C\u{A0}\u{FEFF}"): pa
         return $str;
     }
 
-    public function upper(): parent
+    public function upper(): static
     {
         $str = clone $this;
         $str->string = mb_strtoupper($str->string, 'UTF-8');
diff --git a/src/Symfony/Component/String/ByteString.php b/src/Symfony/Component/String/ByteString.php
index 63183bd489b4c..eaf09671a8256 100644
--- a/src/Symfony/Component/String/ByteString.php
+++ b/src/Symfony/Component/String/ByteString.php
@@ -92,7 +92,7 @@ public function bytesAt(int $offset): array
         return '' === $str ? [] : [\ord($str)];
     }
 
-    public function append(string ...$suffix): parent
+    public function append(string ...$suffix): static
     {
         $str = clone $this;
         $str->string .= 1 >= \count($suffix) ? ($suffix[0] ?? '') : implode('', $suffix);
@@ -100,7 +100,7 @@ public function append(string ...$suffix): parent
         return $str;
     }
 
-    public function camel(): parent
+    public function camel(): static
     {
         $str = clone $this;
         $str->string = lcfirst(str_replace(' ', '', ucwords(preg_replace('/[^a-zA-Z0-9\x7f-\xff]++/', ' ', $this->string))));
@@ -155,7 +155,7 @@ public function equalsTo(string|iterable|AbstractString $string): bool
         return $string === $this->string;
     }
 
-    public function folded(): parent
+    public function folded(): static
     {
         $str = clone $this;
         $str->string = strtolower($str->string);
@@ -202,7 +202,7 @@ public function isUtf8(): bool
         return '' === $this->string || preg_match('//u', $this->string);
     }
 
-    public function join(array $strings, string $lastGlue = null): parent
+    public function join(array $strings, string $lastGlue = null): static
     {
         $str = clone $this;
 
@@ -217,7 +217,7 @@ public function length(): int
         return \strlen($this->string);
     }
 
-    public function lower(): parent
+    public function lower(): static
     {
         $str = clone $this;
         $str->string = strtolower($str->string);
@@ -254,7 +254,7 @@ public function match(string $regexp, int $flags = 0, int $offset = 0): array
         return $matches;
     }
 
-    public function padBoth(int $length, string $padStr = ' '): parent
+    public function padBoth(int $length, string $padStr = ' '): static
     {
         $str = clone $this;
         $str->string = str_pad($this->string, $length, $padStr, \STR_PAD_BOTH);
@@ -262,7 +262,7 @@ public function padBoth(int $length, string $padStr = ' '): parent
         return $str;
     }
 
-    public function padEnd(int $length, string $padStr = ' '): parent
+    public function padEnd(int $length, string $padStr = ' '): static
     {
         $str = clone $this;
         $str->string = str_pad($this->string, $length, $padStr, \STR_PAD_RIGHT);
@@ -270,7 +270,7 @@ public function padEnd(int $length, string $padStr = ' '): parent
         return $str;
     }
 
-    public function padStart(int $length, string $padStr = ' '): parent
+    public function padStart(int $length, string $padStr = ' '): static
     {
         $str = clone $this;
         $str->string = str_pad($this->string, $length, $padStr, \STR_PAD_LEFT);
@@ -278,7 +278,7 @@ public function padStart(int $length, string $padStr = ' '): parent
         return $str;
     }
 
-    public function prepend(string ...$prefix): parent
+    public function prepend(string ...$prefix): static
     {
         $str = clone $this;
         $str->string = (1 >= \count($prefix) ? ($prefix[0] ?? '') : implode('', $prefix)).$str->string;
@@ -286,7 +286,7 @@ public function prepend(string ...$prefix): parent
         return $str;
     }
 
-    public function replace(string $from, string $to): parent
+    public function replace(string $from, string $to): static
     {
         $str = clone $this;
 
@@ -297,7 +297,7 @@ public function replace(string $from, string $to): parent
         return $str;
     }
 
-    public function replaceMatches(string $fromRegexp, string|callable $to): parent
+    public function replaceMatches(string $fromRegexp, string|callable $to): static
     {
         if ($this->ignoreCase) {
             $fromRegexp .= 'i';
@@ -337,7 +337,7 @@ public function replaceMatches(string $fromRegexp, string|callable $to): parent
         return $str;
     }
 
-    public function reverse(): parent
+    public function reverse(): static
     {
         $str = clone $this;
         $str->string = strrev($str->string);
@@ -345,7 +345,7 @@ public function reverse(): parent
         return $str;
     }
 
-    public function slice(int $start = 0, int $length = null): parent
+    public function slice(int $start = 0, int $length = null): static
     {
         $str = clone $this;
         $str->string = (string) substr($this->string, $start, $length ?? \PHP_INT_MAX);
@@ -353,7 +353,7 @@ public function slice(int $start = 0, int $length = null): parent
         return $str;
     }
 
-    public function snake(): parent
+    public function snake(): static
     {
         $str = $this->camel()->title();
         $str->string = strtolower(preg_replace(['/([A-Z]+)([A-Z][a-z])/', '/([a-z\d])([A-Z])/'], '\1_\2', $str->string));
@@ -361,7 +361,7 @@ public function snake(): parent
         return $str;
     }
 
-    public function splice(string $replacement, int $start = 0, int $length = null): parent
+    public function splice(string $replacement, int $start = 0, int $length = null): static
     {
         $str = clone $this;
         $str->string = substr_replace($this->string, $replacement, $start, $length ?? \PHP_INT_MAX);
@@ -407,7 +407,7 @@ public function startsWith(string|iterable|AbstractString $prefix): bool
         return '' !== $prefix && 0 === ($this->ignoreCase ? strncasecmp($this->string, $prefix, \strlen($prefix)) : strncmp($this->string, $prefix, \strlen($prefix)));
     }
 
-    public function title(bool $allWords = false): parent
+    public function title(bool $allWords = false): static
     {
         $str = clone $this;
         $str->string = $allWords ? ucwords($str->string) : ucfirst($str->string);
@@ -457,7 +457,7 @@ public function toCodePointString(string $fromEncoding = null): CodePointString
         return $u;
     }
 
-    public function trim(string $chars = " \t\n\r\0\x0B\x0C"): parent
+    public function trim(string $chars = " \t\n\r\0\x0B\x0C"): static
     {
         $str = clone $this;
         $str->string = trim($str->string, $chars);
@@ -465,7 +465,7 @@ public function trim(string $chars = " \t\n\r\0\x0B\x0C"): parent
         return $str;
     }
 
-    public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C"): parent
+    public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C"): static
     {
         $str = clone $this;
         $str->string = rtrim($str->string, $chars);
@@ -473,7 +473,7 @@ public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C"): parent
         return $str;
     }
 
-    public function trimStart(string $chars = " \t\n\r\0\x0B\x0C"): parent
+    public function trimStart(string $chars = " \t\n\r\0\x0B\x0C"): static
     {
         $str = clone $this;
         $str->string = ltrim($str->string, $chars);
@@ -481,7 +481,7 @@ public function trimStart(string $chars = " \t\n\r\0\x0B\x0C"): parent
         return $str;
     }
 
-    public function upper(): parent
+    public function upper(): static
     {
         $str = clone $this;
         $str->string = strtoupper($str->string);
diff --git a/src/Symfony/Component/String/CodePointString.php b/src/Symfony/Component/String/CodePointString.php
index de52a821942c5..926ff79849a36 100644
--- a/src/Symfony/Component/String/CodePointString.php
+++ b/src/Symfony/Component/String/CodePointString.php
@@ -33,7 +33,7 @@ public function __construct(string $string = '')
         $this->string = $string;
     }
 
-    public function append(string ...$suffix): AbstractString
+    public function append(string ...$suffix): static
     {
         $str = clone $this;
         $str->string .= 1 >= \count($suffix) ? ($suffix[0] ?? '') : implode('', $suffix);
@@ -153,7 +153,7 @@ public function length(): int
         return mb_strlen($this->string, 'UTF-8');
     }
 
-    public function prepend(string ...$prefix): AbstractString
+    public function prepend(string ...$prefix): static
     {
         $str = clone $this;
         $str->string = (1 >= \count($prefix) ? ($prefix[0] ?? '') : implode('', $prefix)).$this->string;
@@ -165,7 +165,7 @@ public function prepend(string ...$prefix): AbstractString
         return $str;
     }
 
-    public function replace(string $from, string $to): AbstractString
+    public function replace(string $from, string $to): static
     {
         $str = clone $this;
 
@@ -186,7 +186,7 @@ public function replace(string $from, string $to): AbstractString
         return $str;
     }
 
-    public function slice(int $start = 0, int $length = null): AbstractString
+    public function slice(int $start = 0, int $length = null): static
     {
         $str = clone $this;
         $str->string = mb_substr($this->string, $start, $length, 'UTF-8');
@@ -194,7 +194,7 @@ public function slice(int $start = 0, int $length = null): AbstractString
         return $str;
     }
 
-    public function splice(string $replacement, int $start = 0, int $length = null): AbstractString
+    public function splice(string $replacement, int $start = 0, int $length = null): static
     {
         if (!preg_match('//u', $replacement)) {
             throw new InvalidArgumentException('Invalid UTF-8 string.');
diff --git a/src/Symfony/Component/String/LazyString.php b/src/Symfony/Component/String/LazyString.php
index ba168888906c6..9a9f94f34b6ab 100644
--- a/src/Symfony/Component/String/LazyString.php
+++ b/src/Symfony/Component/String/LazyString.php
@@ -25,7 +25,7 @@ class LazyString implements \Stringable, \JsonSerializable
      *
      * @return static
      */
-    public static function fromCallable(callable|array $callback, mixed ...$arguments): self
+    public static function fromCallable(callable|array $callback, mixed ...$arguments): static
     {
         if (\is_array($callback) && !\is_callable($callback) && !(($callback[0] ?? null) instanceof \Closure || 2 < \count($callback))) {
             throw new \TypeError(sprintf('Argument 1 passed to "%s()" must be a callable or a [Closure, method] lazy-callable, "%s" given.', __METHOD__, '['.implode(', ', array_map('get_debug_type', $callback)).']'));
@@ -52,7 +52,7 @@ public static function fromCallable(callable|array $callback, mixed ...$argument
     /**
      * @return static
      */
-    public static function fromStringable(string|int|float|bool|\Stringable $value): self
+    public static function fromStringable(string|int|float|bool|\Stringable $value): static
     {
         if (\is_object($value)) {
             return static::fromCallable([$value, '__toString']);
diff --git a/src/Symfony/Component/String/UnicodeString.php b/src/Symfony/Component/String/UnicodeString.php
index b3d4f50fd2150..a33d90d1c2f84 100644
--- a/src/Symfony/Component/String/UnicodeString.php
+++ b/src/Symfony/Component/String/UnicodeString.php
@@ -41,7 +41,7 @@ public function __construct(string $string = '')
         }
     }
 
-    public function append(string ...$suffix): AbstractString
+    public function append(string ...$suffix): static
     {
         $str = clone $this;
         $str->string = $this->string.(1 >= \count($suffix) ? ($suffix[0] ?? '') : implode('', $suffix));
@@ -176,7 +176,7 @@ public function indexOfLast(string|iterable|AbstractString $needle, int $offset
         return false === $i ? null : $i;
     }
 
-    public function join(array $strings, string $lastGlue = null): AbstractString
+    public function join(array $strings, string $lastGlue = null): static
     {
         $str = parent::join($strings, $lastGlue);
         normalizer_is_normalized($str->string) ?: $str->string = normalizer_normalize($str->string);
@@ -192,7 +192,7 @@ public function length(): int
     /**
      * @return static
      */
-    public function normalize(int $form = self::NFC): parent
+    public function normalize(int $form = self::NFC): static
     {
         $str = clone $this;
 
@@ -208,7 +208,7 @@ public function normalize(int $form = self::NFC): parent
         return $str;
     }
 
-    public function prepend(string ...$prefix): AbstractString
+    public function prepend(string ...$prefix): static
     {
         $str = clone $this;
         $str->string = (1 >= \count($prefix) ? ($prefix[0] ?? '') : implode('', $prefix)).$this->string;
@@ -221,7 +221,7 @@ public function prepend(string ...$prefix): AbstractString
         return $str;
     }
 
-    public function replace(string $from, string $to): AbstractString
+    public function replace(string $from, string $to): static
     {
         $str = clone $this;
         normalizer_is_normalized($from) ?: $from = normalizer_normalize($from);
@@ -248,7 +248,7 @@ public function replace(string $from, string $to): AbstractString
         return $str;
     }
 
-    public function replaceMatches(string $fromRegexp, string|callable $to): AbstractString
+    public function replaceMatches(string $fromRegexp, string|callable $to): static
     {
         $str = parent::replaceMatches($fromRegexp, $to);
         normalizer_is_normalized($str->string) ?: $str->string = normalizer_normalize($str->string);
@@ -256,7 +256,7 @@ public function replaceMatches(string $fromRegexp, string|callable $to): Abstrac
         return $str;
     }
 
-    public function slice(int $start = 0, int $length = null): AbstractString
+    public function slice(int $start = 0, int $length = null): static
     {
         $str = clone $this;
 
@@ -265,7 +265,7 @@ public function slice(int $start = 0, int $length = null): AbstractString
         return $str;
     }
 
-    public function splice(string $replacement, int $start = 0, int $length = null): AbstractString
+    public function splice(string $replacement, int $start = 0, int $length = null): static
     {
         $str = clone $this;
 
diff --git a/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php b/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php
index 8e9dc975814cf..b189975ee0b50 100644
--- a/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php
+++ b/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php
@@ -260,7 +260,7 @@ public function setMinDepth(int $minDepth)
      *
      * @return Data The cloned variable represented by a Data object
      */
-    public function cloneVar(mixed $var, int $filter = 0)
+    public function cloneVar(mixed $var, int $filter = 0): Data
     {
         $this->prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = []) {
             if (\E_RECOVERABLE_ERROR === $type || \E_USER_ERROR === $type) {
@@ -295,7 +295,7 @@ public function cloneVar(mixed $var, int $filter = 0)
      *
      * @return array The cloned variable represented in an array
      */
-    abstract protected function doClone(mixed $var);
+    abstract protected function doClone(mixed $var): array;
 
     /**
      * Casts an object to an array representation.
@@ -304,7 +304,7 @@ abstract protected function doClone(mixed $var);
      *
      * @return array The object casted as array
      */
-    protected function castObject(Stub $stub, bool $isNested)
+    protected function castObject(Stub $stub, bool $isNested): array
     {
         $obj = $stub->value;
         $class = $stub->class;
@@ -363,7 +363,7 @@ protected function castObject(Stub $stub, bool $isNested)
      *
      * @return array The resource casted as array
      */
-    protected function castResource(Stub $stub, bool $isNested)
+    protected function castResource(Stub $stub, bool $isNested): array
     {
         $a = [];
         $res = $stub->value;
diff --git a/src/Symfony/Component/VarDumper/Cloner/ClonerInterface.php b/src/Symfony/Component/VarDumper/Cloner/ClonerInterface.php
index fa1df1e8fd3db..d781784159bbb 100644
--- a/src/Symfony/Component/VarDumper/Cloner/ClonerInterface.php
+++ b/src/Symfony/Component/VarDumper/Cloner/ClonerInterface.php
@@ -21,5 +21,5 @@ interface ClonerInterface
      *
      * @return Data The cloned variable represented by a Data object
      */
-    public function cloneVar(mixed $var);
+    public function cloneVar(mixed $var): Data;
 }
diff --git a/src/Symfony/Component/VarDumper/Cloner/Data.php b/src/Symfony/Component/VarDumper/Cloner/Data.php
index 6836a7100b3f2..f50b5bf1d5d84 100644
--- a/src/Symfony/Component/VarDumper/Cloner/Data.php
+++ b/src/Symfony/Component/VarDumper/Cloner/Data.php
@@ -38,7 +38,7 @@ public function __construct(array $data)
     /**
      * @return string|null The type of the value
      */
-    public function getType()
+    public function getType(): ?string
     {
         $item = $this->data[$this->position][$this->key];
 
@@ -69,7 +69,7 @@ public function getType()
      *
      * @return string|int|float|bool|array|Data[]|null A native representation of the original value
      */
-    public function getValue(array|bool $recursive = false)
+    public function getValue(array|bool $recursive = false): string|int|float|bool|array|null
     {
         $item = $this->data[$this->position][$this->key];
 
@@ -136,7 +136,7 @@ public function __get(string $key)
     /**
      * @return bool
      */
-    public function __isset(string $key)
+    public function __isset(string $key): bool
     {
         return null !== $this->seek($key);
     }
@@ -177,7 +177,7 @@ public function __toString(): string
      *
      * @return static
      */
-    public function withMaxDepth(int $maxDepth)
+    public function withMaxDepth(int $maxDepth): static
     {
         $data = clone $this;
         $data->maxDepth = (int) $maxDepth;
@@ -190,7 +190,7 @@ public function withMaxDepth(int $maxDepth)
      *
      * @return static
      */
-    public function withMaxItemsPerDepth(int $maxItemsPerDepth)
+    public function withMaxItemsPerDepth(int $maxItemsPerDepth): static
     {
         $data = clone $this;
         $data->maxItemsPerDepth = (int) $maxItemsPerDepth;
@@ -205,7 +205,7 @@ public function withMaxItemsPerDepth(int $maxItemsPerDepth)
      *
      * @return static
      */
-    public function withRefHandles(bool $useRefHandles)
+    public function withRefHandles(bool $useRefHandles): static
     {
         $data = clone $this;
         $data->useRefHandles = $useRefHandles ? -1 : 0;
@@ -216,7 +216,7 @@ public function withRefHandles(bool $useRefHandles)
     /**
      * @return static
      */
-    public function withContext(array $context)
+    public function withContext(array $context): static
     {
         $data = clone $this;
         $data->context = $context;
@@ -229,7 +229,7 @@ public function withContext(array $context)
      *
      * @return static|null Null if the key is not set
      */
-    public function seek(string|int $key)
+    public function seek(string|int $key): ?static
     {
         $item = $this->data[$this->position][$this->key];
 
diff --git a/src/Symfony/Component/VarDumper/Cloner/VarCloner.php b/src/Symfony/Component/VarDumper/Cloner/VarCloner.php
index 4a6817c1c4869..800bc9566ede8 100644
--- a/src/Symfony/Component/VarDumper/Cloner/VarCloner.php
+++ b/src/Symfony/Component/VarDumper/Cloner/VarCloner.php
@@ -22,7 +22,7 @@ class VarCloner extends AbstractCloner
     /**
      * {@inheritdoc}
      */
-    protected function doClone(mixed $var)
+    protected function doClone(mixed $var): array
     {
         $len = 1;                       // Length of $queue
         $pos = 0;                       // Number of cloned items past the minimum depth
diff --git a/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php b/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php
index 6064ea99f572b..fd9aea3cd1100 100644
--- a/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php
+++ b/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php
@@ -84,7 +84,7 @@ public function setOutput($output)
      *
      * @return string The previous charset
      */
-    public function setCharset(string $charset)
+    public function setCharset(string $charset): string
     {
         $prev = $this->charset;
 
@@ -103,7 +103,7 @@ public function setCharset(string $charset)
      *
      * @return string The previous indent pad
      */
-    public function setIndentPad(string $pad)
+    public function setIndentPad(string $pad): string
     {
         $prev = $this->indentPad;
         $this->indentPad = $pad;
@@ -118,7 +118,7 @@ public function setIndentPad(string $pad)
      *
      * @return string|null The dump as string when $output is true
      */
-    public function dump(Data $data, $output = null)
+    public function dump(Data $data, $output = null): ?string
     {
         $this->decimalPoint = localeconv();
         $this->decimalPoint = $this->decimalPoint['decimal_point'];
@@ -182,7 +182,7 @@ protected function echoLine(string $line, int $depth, string $indentPad)
      *
      * @return string|null The string converted to UTF-8
      */
-    protected function utf8Encode(?string $s)
+    protected function utf8Encode(?string $s): ?string
     {
         if (null === $s || preg_match('//u', $s)) {
             return $s;
diff --git a/src/Symfony/Component/VarDumper/Dumper/CliDumper.php b/src/Symfony/Component/VarDumper/Dumper/CliDumper.php
index 68b85390937e1..2cb5baff83ae6 100644
--- a/src/Symfony/Component/VarDumper/Dumper/CliDumper.php
+++ b/src/Symfony/Component/VarDumper/Dumper/CliDumper.php
@@ -437,7 +437,7 @@ protected function dumpKey(Cursor $cursor)
      *
      * @return string The value with style decoration
      */
-    protected function style(string $style, string $value, array $attr = [])
+    protected function style(string $style, string $value, array $attr = []): string
     {
         if (null === $this->colors) {
             $this->colors = $this->supportsColors();
@@ -513,7 +513,7 @@ protected function style(string $style, string $value, array $attr = [])
     /**
      * @return bool Tells if the current output stream supports ANSI colors or not
      */
-    protected function supportsColors()
+    protected function supportsColors(): bool
     {
         if ($this->outputStream !== static::$defaultOutput) {
             return $this->hasColorSupport($this->outputStream);
diff --git a/src/Symfony/Component/VarDumper/Dumper/HtmlDumper.php b/src/Symfony/Component/VarDumper/Dumper/HtmlDumper.php
index ee4c8da0841ad..f432507806d90 100644
--- a/src/Symfony/Component/VarDumper/Dumper/HtmlDumper.php
+++ b/src/Symfony/Component/VarDumper/Dumper/HtmlDumper.php
@@ -134,7 +134,7 @@ public function setDumpBoundaries(string $prefix, string $suffix)
     /**
      * {@inheritdoc}
      */
-    public function dump(Data $data, $output = null, array $extraDisplayOptions = [])
+    public function dump(Data $data, $output = null, array $extraDisplayOptions = []): ?string
     {
         $this->extraDisplayOptions = $extraDisplayOptions;
         $result = parent::dump($data, $output);
@@ -846,7 +846,7 @@ public function leaveHash(Cursor $cursor, int $type, string|int|null $class, boo
     /**
      * {@inheritdoc}
      */
-    protected function style(string $style, string $value, array $attr = [])
+    protected function style(string $style, string $value, array $attr = []): string
     {
         if ('' === $value) {
             return '';
diff --git a/src/Symfony/Component/WebLink/GenericLinkProvider.php b/src/Symfony/Component/WebLink/GenericLinkProvider.php
index 4cb25a423fc2a..66796e7f9092d 100644
--- a/src/Symfony/Component/WebLink/GenericLinkProvider.php
+++ b/src/Symfony/Component/WebLink/GenericLinkProvider.php
@@ -64,7 +64,7 @@ public function getLinksByRel(string $rel): array
      *
      * @return static
      */
-    public function withLink(LinkInterface $link)
+    public function withLink(LinkInterface $link): static
     {
         $that = clone $this;
         $that->links[spl_object_id($link)] = $link;
@@ -77,7 +77,7 @@ public function withLink(LinkInterface $link)
      *
      * @return static
      */
-    public function withoutLink(LinkInterface $link)
+    public function withoutLink(LinkInterface $link): static
     {
         $that = clone $this;
         unset($that->links[spl_object_id($link)]);
diff --git a/src/Symfony/Component/WebLink/Link.php b/src/Symfony/Component/WebLink/Link.php
index b7785992fdb18..4dccd6c3a4759 100644
--- a/src/Symfony/Component/WebLink/Link.php
+++ b/src/Symfony/Component/WebLink/Link.php
@@ -95,7 +95,7 @@ public function getAttributes(): array
      *
      * @return static
      */
-    public function withHref(string|\Stringable $href)
+    public function withHref(string|\Stringable $href): static
     {
         $that = clone $this;
         $that->href = $href;
@@ -108,7 +108,7 @@ public function withHref(string|\Stringable $href)
      *
      * @return static
      */
-    public function withRel(string $rel)
+    public function withRel(string $rel): static
     {
         $that = clone $this;
         $that->rel[$rel] = $rel;
@@ -121,7 +121,7 @@ public function withRel(string $rel)
      *
      * @return static
      */
-    public function withoutRel(string $rel)
+    public function withoutRel(string $rel): static
     {
         $that = clone $this;
         unset($that->rel[$rel]);
@@ -134,7 +134,7 @@ public function withoutRel(string $rel)
      *
      * @return static
      */
-    public function withAttribute(string $attribute, string|\Stringable|int|float|bool|array $value)
+    public function withAttribute(string $attribute, string|\Stringable|int|float|bool|array $value): static
     {
         $that = clone $this;
         $that->attributes[$attribute] = $value;
@@ -147,7 +147,7 @@ public function withAttribute(string $attribute, string|\Stringable|int|float|bo
      *
      * @return static
      */
-    public function withoutAttribute(string $attribute)
+    public function withoutAttribute(string $attribute): static
     {
         $that = clone $this;
         unset($that->attributes[$attribute]);
diff --git a/src/Symfony/Component/Workflow/DefinitionBuilder.php b/src/Symfony/Component/Workflow/DefinitionBuilder.php
index 9cfdcae772934..b023e62087966 100644
--- a/src/Symfony/Component/Workflow/DefinitionBuilder.php
+++ b/src/Symfony/Component/Workflow/DefinitionBuilder.php
@@ -40,7 +40,7 @@ public function __construct(array $places = [], array $transitions = [])
     /**
      * @return Definition
      */
-    public function build()
+    public function build(): Definition
     {
         return new Definition($this->places, $this->transitions, $this->initialPlaces, $this->metadataStore);
     }
@@ -50,7 +50,7 @@ public function build()
      *
      * @return $this
      */
-    public function clear()
+    public function clear(): static
     {
         $this->places = [];
         $this->transitions = [];
@@ -65,7 +65,7 @@ public function clear()
      *
      * @return $this
      */
-    public function setInitialPlaces(string|array|null $initialPlaces)
+    public function setInitialPlaces(string|array|null $initialPlaces): static
     {
         $this->initialPlaces = $initialPlaces;
 
@@ -75,7 +75,7 @@ public function setInitialPlaces(string|array|null $initialPlaces)
     /**
      * @return $this
      */
-    public function addPlace(string $place)
+    public function addPlace(string $place): static
     {
         if (!$this->places) {
             $this->initialPlaces = $place;
@@ -91,7 +91,7 @@ public function addPlace(string $place)
      *
      * @return $this
      */
-    public function addPlaces(array $places)
+    public function addPlaces(array $places): static
     {
         foreach ($places as $place) {
             $this->addPlace($place);
@@ -105,7 +105,7 @@ public function addPlaces(array $places)
      *
      * @return $this
      */
-    public function addTransitions(array $transitions)
+    public function addTransitions(array $transitions): static
     {
         foreach ($transitions as $transition) {
             $this->addTransition($transition);
@@ -117,7 +117,7 @@ public function addTransitions(array $transitions)
     /**
      * @return $this
      */
-    public function addTransition(Transition $transition)
+    public function addTransition(Transition $transition): static
     {
         $this->transitions[] = $transition;
 
@@ -127,7 +127,7 @@ public function addTransition(Transition $transition)
     /**
      * @return $this
      */
-    public function setMetadataStore(MetadataStoreInterface $metadataStore)
+    public function setMetadataStore(MetadataStoreInterface $metadataStore): static
     {
         $this->metadataStore = $metadataStore;
 
diff --git a/src/Symfony/Component/Workflow/Dumper/DumperInterface.php b/src/Symfony/Component/Workflow/Dumper/DumperInterface.php
index e1d8c7d682b35..1b7461154a6a3 100644
--- a/src/Symfony/Component/Workflow/Dumper/DumperInterface.php
+++ b/src/Symfony/Component/Workflow/Dumper/DumperInterface.php
@@ -27,5 +27,5 @@ interface DumperInterface
      *
      * @return string The representation of the workflow
      */
-    public function dump(Definition $definition, Marking $marking = null, array $options = []);
+    public function dump(Definition $definition, Marking $marking = null, array $options = []): string;
 }
diff --git a/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php b/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php
index a8186a8548c07..37dad66cfe2cb 100644
--- a/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php
+++ b/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php
@@ -44,7 +44,7 @@ class GraphvizDumper implements DumperInterface
      *  * node: The default options for nodes (places + transitions)
      *  * edge: The default options for edges
      */
-    public function dump(Definition $definition, Marking $marking = null, array $options = [])
+    public function dump(Definition $definition, Marking $marking = null, array $options = []): string
     {
         $places = $this->findPlaces($definition, $marking);
         $transitions = $this->findTransitions($definition);
diff --git a/src/Symfony/Component/Workflow/Dumper/StateMachineGraphvizDumper.php b/src/Symfony/Component/Workflow/Dumper/StateMachineGraphvizDumper.php
index 4bd818d5363fc..95b19c497c632 100644
--- a/src/Symfony/Component/Workflow/Dumper/StateMachineGraphvizDumper.php
+++ b/src/Symfony/Component/Workflow/Dumper/StateMachineGraphvizDumper.php
@@ -27,7 +27,7 @@ class StateMachineGraphvizDumper extends GraphvizDumper
      *  * node: The default options for nodes (places)
      *  * edge: The default options for edges
      */
-    public function dump(Definition $definition, Marking $marking = null, array $options = [])
+    public function dump(Definition $definition, Marking $marking = null, array $options = []): string
     {
         $places = $this->findPlaces($definition, $marking);
         $edges = $this->findEdges($definition);
diff --git a/src/Symfony/Component/Workflow/EventListener/AuditTrailListener.php b/src/Symfony/Component/Workflow/EventListener/AuditTrailListener.php
index 95a9590cef4b2..f7a8f66861917 100644
--- a/src/Symfony/Component/Workflow/EventListener/AuditTrailListener.php
+++ b/src/Symfony/Component/Workflow/EventListener/AuditTrailListener.php
@@ -46,7 +46,7 @@ public function onEnter(Event $event)
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             'workflow.leave' => ['onLeave'],
diff --git a/src/Symfony/Component/Workflow/MarkingStore/MarkingStoreInterface.php b/src/Symfony/Component/Workflow/MarkingStore/MarkingStoreInterface.php
index 2d8d6ad731141..a9a2de6e45500 100644
--- a/src/Symfony/Component/Workflow/MarkingStore/MarkingStoreInterface.php
+++ b/src/Symfony/Component/Workflow/MarkingStore/MarkingStoreInterface.php
@@ -29,7 +29,7 @@ interface MarkingStoreInterface
      *
      * @return Marking The marking
      */
-    public function getMarking(object $subject);
+    public function getMarking(object $subject): Marking;
 
     /**
      * Sets a Marking to a subject.
diff --git a/src/Symfony/Component/Workflow/Registry.php b/src/Symfony/Component/Workflow/Registry.php
index 3474e953fa637..2753a8d7368b6 100644
--- a/src/Symfony/Component/Workflow/Registry.php
+++ b/src/Symfony/Component/Workflow/Registry.php
@@ -41,7 +41,7 @@ public function has(object $subject, string $workflowName = null): bool
     /**
      * @return Workflow
      */
-    public function get(object $subject, string $workflowName = null)
+    public function get(object $subject, string $workflowName = null): Workflow
     {
         $matched = [];
 
diff --git a/src/Symfony/Component/Workflow/Tests/WorkflowTest.php b/src/Symfony/Component/Workflow/Tests/WorkflowTest.php
index 6eca532331d03..75885c0bb9e85 100644
--- a/src/Symfony/Component/Workflow/Tests/WorkflowTest.php
+++ b/src/Symfony/Component/Workflow/Tests/WorkflowTest.php
@@ -12,7 +12,6 @@
 use Symfony\Component\Workflow\Exception\NotEnabledTransitionException;
 use Symfony\Component\Workflow\Exception\UndefinedTransitionException;
 use Symfony\Component\Workflow\Marking;
-use Symfony\Component\Workflow\MarkingStore\MarkingStoreInterface;
 use Symfony\Component\Workflow\MarkingStore\MethodMarkingStore;
 use Symfony\Component\Workflow\Transition;
 use Symfony\Component\Workflow\TransitionBlocker;
@@ -23,16 +22,6 @@ class WorkflowTest extends TestCase
 {
     use WorkflowBuilderTrait;
 
-    public function testGetMarkingWithInvalidStoreReturn()
-    {
-        $this->expectException(LogicException::class);
-        $this->expectExceptionMessage('The value returned by the MarkingStore is not an instance of "Symfony\Component\Workflow\Marking" for workflow "unnamed".');
-        $subject = new Subject();
-        $workflow = new Workflow(new Definition([], []), $this->createMock(MarkingStoreInterface::class));
-
-        $workflow->getMarking($subject);
-    }
-
     public function testGetMarkingWithEmptyDefinition()
     {
         $this->expectException(LogicException::class);
diff --git a/src/Symfony/Component/Workflow/Transition.php b/src/Symfony/Component/Workflow/Transition.php
index b6947fe1faed9..b8dc03299428c 100644
--- a/src/Symfony/Component/Workflow/Transition.php
+++ b/src/Symfony/Component/Workflow/Transition.php
@@ -35,7 +35,7 @@ public function __construct(string $name, string|array $froms, string|array $tos
     /**
      * @return string
      */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
@@ -43,7 +43,7 @@ public function getName()
     /**
      * @return string[]
      */
-    public function getFroms()
+    public function getFroms(): array
     {
         return $this->froms;
     }
@@ -51,7 +51,7 @@ public function getFroms()
     /**
      * @return string[]
      */
-    public function getTos()
+    public function getTos(): array
     {
         return $this->tos;
     }
diff --git a/src/Symfony/Component/Workflow/Workflow.php b/src/Symfony/Component/Workflow/Workflow.php
index 12a0bab57a040..fc6c467f7ff2a 100644
--- a/src/Symfony/Component/Workflow/Workflow.php
+++ b/src/Symfony/Component/Workflow/Workflow.php
@@ -79,7 +79,7 @@ public function __construct(Definition $definition, MarkingStoreInterface $marki
     /**
      * {@inheritdoc}
      */
-    public function getMarking(object $subject, array $context = [])
+    public function getMarking(object $subject, array $context = []): Marking
     {
         $marking = $this->markingStore->getMarking($subject);
 
@@ -125,7 +125,7 @@ public function getMarking(object $subject, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function can(object $subject, string $transitionName)
+    public function can(object $subject, string $transitionName): bool
     {
         $transitions = $this->definition->getTransitions();
         $marking = $this->getMarking($subject);
@@ -184,7 +184,7 @@ public function buildTransitionBlockerList(object $subject, string $transitionNa
     /**
      * {@inheritdoc}
      */
-    public function apply(object $subject, string $transitionName, array $context = [])
+    public function apply(object $subject, string $transitionName, array $context = []): Marking
     {
         $marking = $this->getMarking($subject, $context);
 
@@ -252,7 +252,7 @@ public function apply(object $subject, string $transitionName, array $context =
     /**
      * {@inheritdoc}
      */
-    public function getEnabledTransitions(object $subject)
+    public function getEnabledTransitions(object $subject): array
     {
         $enabledTransitions = [];
         $marking = $this->getMarking($subject);
@@ -289,7 +289,7 @@ public function getEnabledTransition(object $subject, string $name): ?Transition
     /**
      * {@inheritdoc}
      */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
@@ -297,7 +297,7 @@ public function getName()
     /**
      * {@inheritdoc}
      */
-    public function getDefinition()
+    public function getDefinition(): Definition
     {
         return $this->definition;
     }
@@ -305,7 +305,7 @@ public function getDefinition()
     /**
      * {@inheritdoc}
      */
-    public function getMarkingStore()
+    public function getMarkingStore(): MarkingStoreInterface
     {
         return $this->markingStore;
     }
diff --git a/src/Symfony/Component/Workflow/WorkflowInterface.php b/src/Symfony/Component/Workflow/WorkflowInterface.php
index 39d9361a5fe72..6dfeca1c067d3 100644
--- a/src/Symfony/Component/Workflow/WorkflowInterface.php
+++ b/src/Symfony/Component/Workflow/WorkflowInterface.php
@@ -27,14 +27,14 @@ interface WorkflowInterface
      *
      * @throws LogicException
      */
-    public function getMarking(object $subject);
+    public function getMarking(object $subject): Marking;
 
     /**
      * Returns true if the transition is enabled.
      *
      * @return bool true if the transition is enabled
      */
-    public function can(object $subject, string $transitionName);
+    public function can(object $subject, string $transitionName): bool;
 
     /**
      * Builds a TransitionBlockerList to know why a transition is blocked.
@@ -48,29 +48,29 @@ public function buildTransitionBlockerList(object $subject, string $transitionNa
      *
      * @throws LogicException If the transition is not applicable
      */
-    public function apply(object $subject, string $transitionName, array $context = []);
+    public function apply(object $subject, string $transitionName, array $context = []): Marking;
 
     /**
      * Returns all enabled transitions.
      *
      * @return Transition[] All enabled transitions
      */
-    public function getEnabledTransitions(object $subject);
+    public function getEnabledTransitions(object $subject): array;
 
     /**
      * @return string
      */
-    public function getName();
+    public function getName(): string;
 
     /**
      * @return Definition
      */
-    public function getDefinition();
+    public function getDefinition(): Definition;
 
     /**
      * @return MarkingStoreInterface
      */
-    public function getMarkingStore();
+    public function getMarkingStore(): MarkingStoreInterface;
 
     public function getMetadataStore(): MetadataStoreInterface;
 }
diff --git a/src/Symfony/Component/Yaml/Command/LintCommand.php b/src/Symfony/Component/Yaml/Command/LintCommand.php
index 32eab0c61b127..bd0c927411927 100644
--- a/src/Symfony/Component/Yaml/Command/LintCommand.php
+++ b/src/Symfony/Component/Yaml/Command/LintCommand.php
@@ -81,7 +81,7 @@ protected function configure()
         ;
     }
 
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): int
     {
         $io = new SymfonyStyle($input, $output);
         $filenames = (array) $input->getArgument('filename');
diff --git a/src/Symfony/Component/Yaml/Exception/ParseException.php b/src/Symfony/Component/Yaml/Exception/ParseException.php
index 74d5a533e1288..9379138703f8c 100644
--- a/src/Symfony/Component/Yaml/Exception/ParseException.php
+++ b/src/Symfony/Component/Yaml/Exception/ParseException.php
@@ -46,7 +46,7 @@ public function __construct(string $message, int $parsedLine = -1, string $snipp
      *
      * @return string The snippet of code
      */
-    public function getSnippet()
+    public function getSnippet(): string
     {
         return $this->snippet;
     }
@@ -68,7 +68,7 @@ public function setSnippet(string $snippet)
      *
      * @return string The filename
      */
-    public function getParsedFile()
+    public function getParsedFile(): string
     {
         return $this->parsedFile;
     }
@@ -88,7 +88,7 @@ public function setParsedFile(string $parsedFile)
      *
      * @return int The file line
      */
-    public function getParsedLine()
+    public function getParsedLine(): int
     {
         return $this->parsedLine;
     }