diff --git a/src/Symfony/Component/HttpFoundation/AcceptHeader.php b/src/Symfony/Component/HttpFoundation/AcceptHeader.php
index bbbd62a6d28ab..90f9f479d5958 100644
--- a/src/Symfony/Component/HttpFoundation/AcceptHeader.php
+++ b/src/Symfony/Component/HttpFoundation/AcceptHeader.php
@@ -44,15 +44,13 @@ public function __construct(array $items)
     /**
      * Builds an AcceptHeader instance from a string.
      *
-     * @param string $headerValue
-     *
      * @return self
      */
-    public static function fromString($headerValue)
+    public static function fromString(?string $headerValue)
     {
         $index = 0;
 
-        $parts = HeaderUtils::split((string) $headerValue, ',;=');
+        $parts = HeaderUtils::split($headerValue ?? '', ',;=');
 
         return new self(array_map(function ($subParts) use (&$index) {
             $part = array_shift($subParts);
@@ -78,11 +76,9 @@ public function __toString()
     /**
      * Tests if header has given value.
      *
-     * @param string $value
-     *
      * @return bool
      */
-    public function has($value)
+    public function has(string $value)
     {
         return isset($this->items[$value]);
     }
@@ -90,11 +86,9 @@ public function has($value)
     /**
      * Returns given value's item, if exists.
      *
-     * @param string $value
-     *
      * @return AcceptHeaderItem|null
      */
-    public function get($value)
+    public function get(string $value)
     {
         return $this->items[$value] ?? $this->items[explode('/', $value)[0].'/*'] ?? $this->items['*/*'] ?? $this->items['*'] ?? null;
     }
@@ -127,11 +121,9 @@ public function all()
     /**
      * Filters items on their value using given regex.
      *
-     * @param string $pattern
-     *
      * @return self
      */
-    public function filter($pattern)
+    public function filter(string $pattern)
     {
         return new self(array_filter($this->items, function (AcceptHeaderItem $item) use ($pattern) {
             return preg_match($pattern, $item->getValue());
diff --git a/src/Symfony/Component/HttpFoundation/AcceptHeaderItem.php b/src/Symfony/Component/HttpFoundation/AcceptHeaderItem.php
index 954aac6014544..bc4014e581693 100644
--- a/src/Symfony/Component/HttpFoundation/AcceptHeaderItem.php
+++ b/src/Symfony/Component/HttpFoundation/AcceptHeaderItem.php
@@ -34,13 +34,11 @@ public function __construct(string $value, array $attributes = [])
     /**
      * Builds an AcceptHeaderInstance instance from a string.
      *
-     * @param string $itemValue
-     *
      * @return self
      */
-    public static function fromString($itemValue)
+    public static function fromString(?string $itemValue)
     {
-        $parts = HeaderUtils::split($itemValue, ';=');
+        $parts = HeaderUtils::split($itemValue ?? '', ';=');
 
         $part = array_shift($parts);
         $attributes = HeaderUtils::combine($parts);
@@ -66,11 +64,9 @@ public function __toString()
     /**
      * Set the item value.
      *
-     * @param string $value
-     *
      * @return $this
      */
-    public function setValue($value)
+    public function setValue(string $value)
     {
         $this->value = $value;
 
@@ -90,11 +86,9 @@ public function getValue()
     /**
      * Set the item quality.
      *
-     * @param float $quality
-     *
      * @return $this
      */
-    public function setQuality($quality)
+    public function setQuality(float $quality)
     {
         $this->quality = $quality;
 
@@ -114,11 +108,9 @@ public function getQuality()
     /**
      * Set the item index.
      *
-     * @param int $index
-     *
      * @return $this
      */
-    public function setIndex($index)
+    public function setIndex(int $index)
     {
         $this->index = $index;
 
@@ -138,11 +130,9 @@ public function getIndex()
     /**
      * Tests if an attribute exists.
      *
-     * @param string $name
-     *
      * @return bool
      */
-    public function hasAttribute($name)
+    public function hasAttribute(string $name)
     {
         return isset($this->attributes[$name]);
     }
@@ -150,12 +140,11 @@ public function hasAttribute($name)
     /**
      * Returns an attribute by its name.
      *
-     * @param string $name
-     * @param mixed  $default
+     * @param mixed $default
      *
      * @return mixed
      */
-    public function getAttribute($name, $default = null)
+    public function getAttribute(string $name, $default = null)
     {
         return isset($this->attributes[$name]) ? $this->attributes[$name] : $default;
     }
@@ -173,17 +162,14 @@ public function getAttributes()
     /**
      * Set an attribute.
      *
-     * @param string $name
-     * @param string $value
-     *
      * @return $this
      */
-    public function setAttribute($name, $value)
+    public function setAttribute(string $name, string $value)
     {
         if ('q' === $name) {
             $this->quality = (float) $value;
         } else {
-            $this->attributes[$name] = (string) $value;
+            $this->attributes[$name] = $value;
         }
 
         return $this;
diff --git a/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php b/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
index 4fd4aec1af296..3f70232e091d8 100644
--- a/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
+++ b/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
@@ -66,7 +66,7 @@ public function __construct($file, int $status = 200, array $headers = [], bool
      *
      * @return static
      */
-    public static function create($file = null, $status = 200, $headers = [], $public = true, $contentDisposition = null, $autoEtag = false, $autoLastModified = true)
+    public static function create($file = null, int $status = 200, array $headers = [], bool $public = true, string $contentDisposition = null, bool $autoEtag = false, bool $autoLastModified = true)
     {
         return new static($file, $status, $headers, $public, $contentDisposition, $autoEtag, $autoLastModified);
     }
@@ -74,16 +74,13 @@ public static function create($file = null, $status = 200, $headers = [], $publi
     /**
      * Sets the file to stream.
      *
-     * @param \SplFileInfo|string $file               The file to stream
-     * @param string              $contentDisposition
-     * @param bool                $autoEtag
-     * @param bool                $autoLastModified
+     * @param \SplFileInfo|string $file The file to stream
      *
      * @return $this
      *
      * @throws FileException
      */
-    public function setFile($file, $contentDisposition = null, $autoEtag = false, $autoLastModified = true)
+    public function setFile($file, string $contentDisposition = null, bool $autoEtag = false, bool $autoLastModified = true)
     {
         if (!$file instanceof File) {
             if ($file instanceof \SplFileInfo) {
@@ -153,7 +150,7 @@ public function setAutoEtag()
      *
      * @return $this
      */
-    public function setContentDisposition($disposition, $filename = '', $filenameFallback = '')
+    public function setContentDisposition(string $disposition, string $filename = '', string $filenameFallback = '')
     {
         if ('' === $filename) {
             $filename = $this->file->getFilename();
@@ -317,7 +314,7 @@ public function sendContent()
      *
      * @throws \LogicException when the content is not null
      */
-    public function setContent($content)
+    public function setContent(?string $content)
     {
         if (null !== $content) {
             throw new \LogicException('The content cannot be set on a BinaryFileResponse instance.');
@@ -346,11 +343,9 @@ public static function trustXSendfileTypeHeader()
      * If this is set to true, the file will be unlinked after the request is send
      * Note: If the X-Sendfile header is used, the deleteFileAfterSend setting will not be used.
      *
-     * @param bool $shouldDelete
-     *
      * @return $this
      */
-    public function deleteFileAfterSend($shouldDelete = true)
+    public function deleteFileAfterSend(bool $shouldDelete = true)
     {
         $this->deleteFileAfterSend = $shouldDelete;
 
diff --git a/src/Symfony/Component/HttpFoundation/Cookie.php b/src/Symfony/Component/HttpFoundation/Cookie.php
index 9391076df8659..6ada5889f6f84 100644
--- a/src/Symfony/Component/HttpFoundation/Cookie.php
+++ b/src/Symfony/Component/HttpFoundation/Cookie.php
@@ -36,12 +36,9 @@ class Cookie
     /**
      * Creates cookie from raw header string.
      *
-     * @param string $cookie
-     * @param bool   $decode
-     *
      * @return static
      */
-    public static function fromString($cookie, $decode = false)
+    public static function fromString(string $cookie, bool $decode = false)
     {
         $data = [
             'expires' => 0,
diff --git a/src/Symfony/Component/HttpFoundation/File/File.php b/src/Symfony/Component/HttpFoundation/File/File.php
index 4906588a72aa1..d79c27f68ef79 100644
--- a/src/Symfony/Component/HttpFoundation/File/File.php
+++ b/src/Symfony/Component/HttpFoundation/File/File.php
@@ -76,14 +76,11 @@ public function getMimeType()
     /**
      * Moves the file to a new location.
      *
-     * @param string $directory The destination folder
-     * @param string $name      The new file name
-     *
      * @return self A File object representing the new file
      *
      * @throws FileException if the target file could not be created
      */
-    public function move($directory, $name = null)
+    public function move(string $directory, string $name = null)
     {
         $target = $this->getTargetFile($directory, $name);
 
@@ -102,7 +99,7 @@ public function move($directory, $name = null)
     /**
      * @return self
      */
-    protected function getTargetFile($directory, $name = null)
+    protected function getTargetFile(string $directory, string $name = null)
     {
         if (!is_dir($directory)) {
             if (false === @mkdir($directory, 0777, true) && !is_dir($directory)) {
@@ -120,11 +117,9 @@ protected function getTargetFile($directory, $name = null)
     /**
      * Returns locale independent base name of the given path.
      *
-     * @param string $name The new file name
-     *
      * @return string
      */
-    protected function getName($name)
+    protected function getName(string $name)
     {
         $originalName = str_replace('\\', '/', $name);
         $pos = strrpos($originalName, '/');
diff --git a/src/Symfony/Component/HttpFoundation/File/UploadedFile.php b/src/Symfony/Component/HttpFoundation/File/UploadedFile.php
index 3ea8ab55e6aee..a2ed4262d4457 100644
--- a/src/Symfony/Component/HttpFoundation/File/UploadedFile.php
+++ b/src/Symfony/Component/HttpFoundation/File/UploadedFile.php
@@ -164,14 +164,11 @@ public function isValid()
     /**
      * Moves the file to a new location.
      *
-     * @param string $directory The destination folder
-     * @param string $name      The new file name
-     *
      * @return File A File object representing the new file
      *
      * @throws FileException if, for any reason, the file could not have been moved
      */
-    public function move($directory, $name = null)
+    public function move(string $directory, string $name = null)
     {
         if ($this->isValid()) {
             if ($this->test) {
diff --git a/src/Symfony/Component/HttpFoundation/FileBag.php b/src/Symfony/Component/HttpFoundation/FileBag.php
index eec3ff4465916..3a131e8243bc4 100644
--- a/src/Symfony/Component/HttpFoundation/FileBag.php
+++ b/src/Symfony/Component/HttpFoundation/FileBag.php
@@ -43,7 +43,7 @@ public function replace(array $files = [])
     /**
      * {@inheritdoc}
      */
-    public function set($key, $value)
+    public function set(string $key, $value)
     {
         if (!\is_array($value) && !$value instanceof UploadedFile) {
             throw new \InvalidArgumentException('An uploaded file must be an array or an instance of UploadedFile.');
diff --git a/src/Symfony/Component/HttpFoundation/HeaderBag.php b/src/Symfony/Component/HttpFoundation/HeaderBag.php
index dd0e0f3966cf6..6a6ebdf3c2492 100644
--- a/src/Symfony/Component/HttpFoundation/HeaderBag.php
+++ b/src/Symfony/Component/HttpFoundation/HeaderBag.php
@@ -102,14 +102,11 @@ public function add(array $headers)
     /**
      * Returns a header value by name.
      *
-     * @param string      $key     The header name
-     * @param string|null $default The default value
-     *
      * @return string|null The first header value or default value
      */
-    public function get($key, $default = null)
+    public function get(string $key, string $default = null)
     {
-        $headers = $this->all((string) $key);
+        $headers = $this->all($key);
 
         return $headers[0] ?? $default;
     }
@@ -117,11 +114,10 @@ public function get($key, $default = null)
     /**
      * Sets a header by name.
      *
-     * @param string          $key     The key
      * @param string|string[] $values  The value or an array of values
      * @param bool            $replace Whether to replace the actual value or not (true by default)
      */
-    public function set($key, $values, $replace = true)
+    public function set(string $key, $values, bool $replace = true)
     {
         $key = str_replace('_', '-', strtolower($key));
 
@@ -149,11 +145,9 @@ public function set($key, $values, $replace = true)
     /**
      * Returns true if the HTTP header is defined.
      *
-     * @param string $key The HTTP header
-     *
      * @return bool true if the parameter exists, false otherwise
      */
-    public function has($key)
+    public function has(string $key)
     {
         return \array_key_exists(str_replace('_', '-', strtolower($key)), $this->all());
     }
@@ -161,22 +155,17 @@ public function has($key)
     /**
      * Returns true if the given HTTP header contains the given value.
      *
-     * @param string $key   The HTTP header name
-     * @param string $value The HTTP value
-     *
      * @return bool true if the value is contained in the header, false otherwise
      */
-    public function contains($key, $value)
+    public function contains(string $key, string $value)
     {
-        return \in_array($value, $this->all((string) $key));
+        return \in_array($value, $this->all($key));
     }
 
     /**
      * Removes a header.
-     *
-     * @param string $key The HTTP header name
      */
-    public function remove($key)
+    public function remove(string $key)
     {
         $key = str_replace('_', '-', strtolower($key));
 
@@ -190,13 +179,11 @@ public function remove($key)
     /**
      * Returns the HTTP header value converted to a date.
      *
-     * @param string $key The parameter key
-     *
      * @return \DateTimeInterface|null The parsed DateTime or the default value if the header does not exist
      *
      * @throws \RuntimeException When the HTTP header is not parseable
      */
-    public function getDate($key, \DateTime $default = null)
+    public function getDate(string $key, \DateTime $default = null)
     {
         if (null === $value = $this->get($key)) {
             return $default;
@@ -212,10 +199,9 @@ public function getDate($key, \DateTime $default = null)
     /**
      * Adds a custom Cache-Control directive.
      *
-     * @param string $key   The Cache-Control directive name
-     * @param mixed  $value The Cache-Control directive value
+     * @param mixed $value The Cache-Control directive value
      */
-    public function addCacheControlDirective($key, $value = true)
+    public function addCacheControlDirective(string $key, $value = true)
     {
         $this->cacheControl[$key] = $value;
 
@@ -225,11 +211,9 @@ public function addCacheControlDirective($key, $value = true)
     /**
      * Returns true if the Cache-Control directive is defined.
      *
-     * @param string $key The Cache-Control directive
-     *
      * @return bool true if the directive exists, false otherwise
      */
-    public function hasCacheControlDirective($key)
+    public function hasCacheControlDirective(string $key)
     {
         return \array_key_exists($key, $this->cacheControl);
     }
@@ -237,21 +221,17 @@ public function hasCacheControlDirective($key)
     /**
      * Returns a Cache-Control directive value by name.
      *
-     * @param string $key The directive name
-     *
      * @return mixed|null The directive value if defined, null otherwise
      */
-    public function getCacheControlDirective($key)
+    public function getCacheControlDirective(string $key)
     {
         return \array_key_exists($key, $this->cacheControl) ? $this->cacheControl[$key] : null;
     }
 
     /**
      * Removes a Cache-Control directive.
-     *
-     * @param string $key The Cache-Control directive
      */
-    public function removeCacheControlDirective($key)
+    public function removeCacheControlDirective(string $key)
     {
         unset($this->cacheControl[$key]);
 
@@ -288,11 +268,9 @@ protected function getCacheControlHeader()
     /**
      * Parses a Cache-Control HTTP header.
      *
-     * @param string $header The value of the Cache-Control HTTP header
-     *
      * @return array An array representing the attribute values
      */
-    protected function parseCacheControl($header)
+    protected function parseCacheControl(string $header)
     {
         $parts = HeaderUtils::split($header, ',=');
 
diff --git a/src/Symfony/Component/HttpFoundation/IpUtils.php b/src/Symfony/Component/HttpFoundation/IpUtils.php
index 67d13e57aafce..68b472d64a81d 100644
--- a/src/Symfony/Component/HttpFoundation/IpUtils.php
+++ b/src/Symfony/Component/HttpFoundation/IpUtils.php
@@ -30,12 +30,11 @@ private function __construct()
     /**
      * Checks if an IPv4 or IPv6 address is contained in the list of given IPs or subnets.
      *
-     * @param string       $requestIp IP to check
-     * @param string|array $ips       List of IPs or subnets (can be a string if only a single one)
+     * @param string|array $ips List of IPs or subnets (can be a string if only a single one)
      *
      * @return bool Whether the IP is valid
      */
-    public static function checkIp($requestIp, $ips)
+    public static function checkIp(?string $requestIp, $ips)
     {
         if (!\is_array($ips)) {
             $ips = [$ips];
@@ -56,12 +55,11 @@ public static function checkIp($requestIp, $ips)
      * Compares two IPv4 addresses.
      * In case a subnet is given, it checks if it contains the request IP.
      *
-     * @param string $requestIp IPv4 address to check
-     * @param string $ip        IPv4 address or subnet in CIDR notation
+     * @param string $ip IPv4 address or subnet in CIDR notation
      *
      * @return bool Whether the request IP matches the IP, or whether the request IP is within the CIDR subnet
      */
-    public static function checkIp4($requestIp, $ip)
+    public static function checkIp4(?string $requestIp, string $ip)
     {
         $cacheKey = $requestIp.'-'.$ip;
         if (isset(self::$checkedIps[$cacheKey])) {
@@ -102,14 +100,13 @@ public static function checkIp4($requestIp, $ip)
      *
      * @see https://github.com/dsp/v6tools
      *
-     * @param string $requestIp IPv6 address to check
-     * @param string $ip        IPv6 address or subnet in CIDR notation
+     * @param string $ip IPv6 address or subnet in CIDR notation
      *
      * @return bool Whether the IP is valid
      *
      * @throws \RuntimeException When IPV6 support is not enabled
      */
-    public static function checkIp6($requestIp, $ip)
+    public static function checkIp6(?string $requestIp, string $ip)
     {
         $cacheKey = $requestIp.'-'.$ip;
         if (isset(self::$checkedIps[$cacheKey])) {
diff --git a/src/Symfony/Component/HttpFoundation/JsonResponse.php b/src/Symfony/Component/HttpFoundation/JsonResponse.php
index 11a0bebf88302..f2a4e60b13b60 100644
--- a/src/Symfony/Component/HttpFoundation/JsonResponse.php
+++ b/src/Symfony/Component/HttpFoundation/JsonResponse.php
@@ -64,7 +64,7 @@ public function __construct($data = null, int $status = 200, array $headers = []
      *
      * @return static
      */
-    public static function create($data = null, $status = 200, $headers = [])
+    public static function create($data = null, int $status = 200, array $headers = [])
     {
         return new static($data, $status, $headers);
     }
@@ -83,7 +83,7 @@ public static function create($data = null, $status = 200, $headers = [])
      *
      * @return static
      */
-    public static function fromJsonString($data = null, $status = 200, $headers = [])
+    public static function fromJsonString($data = null, int $status = 200, array $headers = [])
     {
         return new static($data, $status, $headers, true);
     }
@@ -97,7 +97,7 @@ public static function fromJsonString($data = null, $status = 200, $headers = []
      *
      * @throws \InvalidArgumentException When the callback name is not valid
      */
-    public function setCallback($callback = null)
+    public function setCallback(string $callback = null)
     {
         if (null !== $callback) {
             // partially taken from https://geekality.net/2011/08/03/valid-javascript-identifier/
@@ -126,13 +126,11 @@ public function setCallback($callback = null)
     /**
      * Sets a raw string containing a JSON document to be sent.
      *
-     * @param string $json
-     *
      * @return $this
      *
      * @throws \InvalidArgumentException
      */
-    public function setJson($json)
+    public function setJson(string $json)
     {
         $this->data = $json;
 
@@ -183,13 +181,11 @@ public function getEncodingOptions()
     /**
      * Sets options used while encoding data to JSON.
      *
-     * @param int $encodingOptions
-     *
      * @return $this
      */
-    public function setEncodingOptions($encodingOptions)
+    public function setEncodingOptions(int $encodingOptions)
     {
-        $this->encodingOptions = (int) $encodingOptions;
+        $this->encodingOptions = $encodingOptions;
 
         return $this->setData(json_decode($this->data));
     }
diff --git a/src/Symfony/Component/HttpFoundation/ParameterBag.php b/src/Symfony/Component/HttpFoundation/ParameterBag.php
index 20ca6758b68bc..bf021a55b1c71 100644
--- a/src/Symfony/Component/HttpFoundation/ParameterBag.php
+++ b/src/Symfony/Component/HttpFoundation/ParameterBag.php
@@ -67,12 +67,11 @@ public function add(array $parameters = [])
     /**
      * Returns a parameter by name.
      *
-     * @param string $key     The key
-     * @param mixed  $default The default value if the parameter key does not exist
+     * @param mixed $default The default value if the parameter key does not exist
      *
      * @return mixed
      */
-    public function get($key, $default = null)
+    public function get(string $key, $default = null)
     {
         return \array_key_exists($key, $this->parameters) ? $this->parameters[$key] : $default;
     }
@@ -80,10 +79,9 @@ public function get($key, $default = null)
     /**
      * Sets a parameter by name.
      *
-     * @param string $key   The key
-     * @param mixed  $value The value
+     * @param mixed $value The value
      */
-    public function set($key, $value)
+    public function set(string $key, $value)
     {
         $this->parameters[$key] = $value;
     }
@@ -91,21 +89,17 @@ public function set($key, $value)
     /**
      * Returns true if the parameter is defined.
      *
-     * @param string $key The key
-     *
      * @return bool true if the parameter exists, false otherwise
      */
-    public function has($key)
+    public function has(string $key)
     {
         return \array_key_exists($key, $this->parameters);
     }
 
     /**
      * Removes a parameter.
-     *
-     * @param string $key The key
      */
-    public function remove($key)
+    public function remove(string $key)
     {
         unset($this->parameters[$key]);
     }
@@ -113,12 +107,9 @@ public function remove($key)
     /**
      * Returns the alphabetic characters of the parameter value.
      *
-     * @param string $key     The parameter key
-     * @param string $default The default value if the parameter key does not exist
-     *
      * @return string The filtered value
      */
-    public function getAlpha($key, $default = '')
+    public function getAlpha(string $key, string $default = '')
     {
         return preg_replace('/[^[:alpha:]]/', '', $this->get($key, $default));
     }
@@ -126,12 +117,9 @@ public function getAlpha($key, $default = '')
     /**
      * Returns the alphabetic characters and digits of the parameter value.
      *
-     * @param string $key     The parameter key
-     * @param string $default The default value if the parameter key does not exist
-     *
      * @return string The filtered value
      */
-    public function getAlnum($key, $default = '')
+    public function getAlnum(string $key, string $default = '')
     {
         return preg_replace('/[^[:alnum:]]/', '', $this->get($key, $default));
     }
@@ -139,12 +127,9 @@ public function getAlnum($key, $default = '')
     /**
      * Returns the digits of the parameter value.
      *
-     * @param string $key     The parameter key
-     * @param string $default The default value if the parameter key does not exist
-     *
      * @return string The filtered value
      */
-    public function getDigits($key, $default = '')
+    public function getDigits(string $key, string $default = '')
     {
         // we need to remove - and + because they're allowed in the filter
         return str_replace(['-', '+'], '', $this->filter($key, $default, FILTER_SANITIZE_NUMBER_INT));
@@ -153,25 +138,19 @@ public function getDigits($key, $default = '')
     /**
      * Returns the parameter value converted to integer.
      *
-     * @param string $key     The parameter key
-     * @param int    $default The default value if the parameter key does not exist
-     *
      * @return int The filtered value
      */
-    public function getInt($key, $default = 0)
+    public function getInt(string $key, int $default = 0)
     {
-        return (int) $this->get($key, $default);
+        return $this->get($key, $default);
     }
 
     /**
      * Returns the parameter value converted to boolean.
      *
-     * @param string $key     The parameter key
-     * @param bool   $default The default value if the parameter key does not exist
-     *
      * @return bool The filtered value
      */
-    public function getBoolean($key, $default = false)
+    public function getBoolean(string $key, bool $default = false)
     {
         return $this->filter($key, $default, FILTER_VALIDATE_BOOLEAN);
     }
@@ -179,16 +158,15 @@ public function getBoolean($key, $default = false)
     /**
      * Filter key.
      *
-     * @param string $key     Key
-     * @param mixed  $default Default = null
-     * @param int    $filter  FILTER_* constant
-     * @param mixed  $options Filter options
+     * @param mixed $default Default = null
+     * @param int   $filter  FILTER_* constant
+     * @param mixed $options Filter options
      *
      * @see https://php.net/filter-var
      *
      * @return mixed
      */
-    public function filter($key, $default = null, $filter = FILTER_DEFAULT, $options = [])
+    public function filter(string $key, $default = null, int $filter = FILTER_DEFAULT, $options = [])
     {
         $value = $this->get($key, $default);
 
diff --git a/src/Symfony/Component/HttpFoundation/RedirectResponse.php b/src/Symfony/Component/HttpFoundation/RedirectResponse.php
index 621a3d8d359ca..c7da9f61cad7d 100644
--- a/src/Symfony/Component/HttpFoundation/RedirectResponse.php
+++ b/src/Symfony/Component/HttpFoundation/RedirectResponse.php
@@ -50,13 +50,11 @@ public function __construct(string $url, int $status = 302, array $headers = [])
     /**
      * Factory method for chainability.
      *
-     * @param string $url     The url to redirect to
-     * @param int    $status  The response status code
-     * @param array  $headers An array of response headers
+     * @param string $url The URL to redirect to
      *
      * @return static
      */
-    public static function create($url = '', $status = 302, $headers = [])
+    public static function create($url = '', int $status = 302, array $headers = [])
     {
         return new static($url, $status, $headers);
     }
@@ -74,15 +72,13 @@ public function getTargetUrl()
     /**
      * Sets the redirect target of this response.
      *
-     * @param string $url The URL to redirect to
-     *
      * @return $this
      *
      * @throws \InvalidArgumentException
      */
-    public function setTargetUrl($url)
+    public function setTargetUrl(string $url)
     {
-        if ('' === ($url ?? '')) {
+        if ('' === $url) {
             throw new \InvalidArgumentException('Cannot redirect to an empty URL.');
         }
 
diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index 8368ba655ed3b..309565fc109a1 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -310,7 +310,7 @@ public static function createFromGlobals()
      *
      * @return static
      */
-    public static function create($uri, $method = 'GET', $parameters = [], $cookies = [], $files = [], $server = [], $content = null)
+    public static function create(string $uri, string $method = 'GET', array $parameters = [], array $cookies = [], array $files = [], array $server = [], $content = null)
     {
         $server = array_replace([
             'SERVER_NAME' => 'localhost',
@@ -408,10 +408,8 @@ public static function create($uri, $method = 'GET', $parameters = [], $cookies
      * This is mainly useful when you need to override the Request class
      * to keep BC with an existing system. It should not be used for any
      * other purpose.
-     *
-     * @param callable|null $callable A PHP callable
      */
-    public static function setFactory($callable)
+    public static function setFactory(?callable $callable)
     {
         self::$requestFactory = $callable;
     }
@@ -626,11 +624,9 @@ public static function getTrustedHosts()
      * It builds a normalized query string, where keys/value pairs are alphabetized,
      * have consistent escaping and unneeded delimiters are removed.
      *
-     * @param string $qs Query string
-     *
      * @return string A normalized query string for the Request
      */
-    public static function normalizeQueryString($qs)
+    public static function normalizeQueryString(?string $qs)
     {
         if ('' === ($qs ?? '')) {
             return '';
@@ -677,12 +673,11 @@ public static function getHttpMethodParameterOverride()
      *
      * Order of precedence: PATH (routing placeholders or custom attributes), GET, BODY
      *
-     * @param string $key     The key
-     * @param mixed  $default The default value if the parameter key does not exist
+     * @param mixed $default The default value if the parameter key does not exist
      *
      * @return mixed
      */
-    public function get($key, $default = null)
+    public function get(string $key, $default = null)
     {
         if ($this !== $result = $this->attributes->get($key, $this)) {
             return $result;
@@ -1028,7 +1023,7 @@ public function getUri()
      *
      * @return string The normalized URI for the path
      */
-    public function getUriForPath($path)
+    public function getUriForPath(string $path)
     {
         return $this->getSchemeAndHttpHost().$this->getBaseUrl().$path;
     }
@@ -1048,11 +1043,9 @@ public function getUriForPath($path)
      * - "/a/b/c/other" -> "other"
      * - "/a/x/y"       -> "../../x/y"
      *
-     * @param string $path The target path
-     *
      * @return string The relative target path
      */
-    public function getRelativeUriForPath($path)
+    public function getRelativeUriForPath(string $path)
     {
         // be sure that we are dealing with an absolute path
         if (!isset($path[0]) || '/' !== $path[0]) {
@@ -1190,10 +1183,8 @@ public function getHost()
 
     /**
      * Sets the request method.
-     *
-     * @param string $method
      */
-    public function setMethod($method)
+    public function setMethod(string $method)
     {
         $this->method = null;
         $this->server->set('REQUEST_METHOD', $method);
@@ -1264,11 +1255,9 @@ public function getRealMethod()
     /**
      * Gets the mime type associated with the format.
      *
-     * @param string $format The format
-     *
      * @return string|null The associated mime type (null if not found)
      */
-    public function getMimeType($format)
+    public function getMimeType(string $format)
     {
         if (null === static::$formats) {
             static::initializeFormats();
@@ -1280,11 +1269,9 @@ public function getMimeType($format)
     /**
      * Gets the mime types associated with the format.
      *
-     * @param string $format The format
-     *
      * @return array The associated mime types
      */
-    public static function getMimeTypes($format)
+    public static function getMimeTypes(string $format)
     {
         if (null === static::$formats) {
             static::initializeFormats();
@@ -1296,11 +1283,9 @@ public static function getMimeTypes($format)
     /**
      * Gets the format associated with the mime type.
      *
-     * @param string $mimeType The associated mime type
-     *
      * @return string|null The format (null if not found)
      */
-    public function getFormat($mimeType)
+    public function getFormat(?string $mimeType)
     {
         $canonicalMimeType = null;
         if (false !== $pos = strpos($mimeType, ';')) {
@@ -1324,10 +1309,9 @@ public function getFormat($mimeType)
     /**
      * Associates a format with mime types.
      *
-     * @param string       $format    The format
      * @param string|array $mimeTypes The associated mime types (the preferred one must be the first as it will be used as the content type)
      */
-    public function setFormat($format, $mimeTypes)
+    public function setFormat(?string $format, $mimeTypes)
     {
         if (null === static::$formats) {
             static::initializeFormats();
@@ -1347,11 +1331,9 @@ public function setFormat($format, $mimeTypes)
      *
      * @see getPreferredFormat
      *
-     * @param string|null $default The default format
-     *
      * @return string|null The request format
      */
-    public function getRequestFormat($default = 'html')
+    public function getRequestFormat(?string $default = 'html')
     {
         if (null === $this->format) {
             $this->format = $this->attributes->get('_format');
@@ -1362,10 +1344,8 @@ public function getRequestFormat($default = 'html')
 
     /**
      * Sets the request format.
-     *
-     * @param string $format The request format
      */
-    public function setRequestFormat($format)
+    public function setRequestFormat(?string $format)
     {
         $this->format = $format;
     }
@@ -1382,10 +1362,8 @@ public function getContentType()
 
     /**
      * Sets the default locale.
-     *
-     * @param string $locale
      */
-    public function setDefaultLocale($locale)
+    public function setDefaultLocale(string $locale)
     {
         $this->defaultLocale = $locale;
 
@@ -1406,10 +1384,8 @@ public function getDefaultLocale()
 
     /**
      * Sets the locale.
-     *
-     * @param string $locale
      */
-    public function setLocale($locale)
+    public function setLocale(string $locale)
     {
         $this->setPhpDefaultLocale($this->locale = $locale);
     }
@@ -1431,7 +1407,7 @@ public function getLocale()
      *
      * @return bool
      */
-    public function isMethod($method)
+    public function isMethod(string $method)
     {
         return $this->getMethod() === strtoupper($method);
     }
@@ -1503,7 +1479,7 @@ public function getProtocolVersion()
      *
      * @throws \LogicException
      */
-    public function getContent($asResource = false)
+    public function getContent(bool $asResource = false)
     {
         $currentContentIsResource = \is_resource($this->content);
 
diff --git a/src/Symfony/Component/HttpFoundation/RequestMatcher.php b/src/Symfony/Component/HttpFoundation/RequestMatcher.php
index 9a4a2a13761e1..c32c5cdce5e1c 100644
--- a/src/Symfony/Component/HttpFoundation/RequestMatcher.php
+++ b/src/Symfony/Component/HttpFoundation/RequestMatcher.php
@@ -84,10 +84,8 @@ public function matchScheme($scheme)
 
     /**
      * Adds a check for the URL host name.
-     *
-     * @param string|null $regexp A Regexp
      */
-    public function matchHost($regexp)
+    public function matchHost(?string $regexp)
     {
         $this->host = $regexp;
     }
@@ -104,10 +102,8 @@ public function matchPort(?int $port)
 
     /**
      * Adds a check for the URL path info.
-     *
-     * @param string|null $regexp A Regexp
      */
-    public function matchPath($regexp)
+    public function matchPath(?string $regexp)
     {
         $this->path = $regexp;
     }
@@ -117,7 +113,7 @@ public function matchPath($regexp)
      *
      * @param string $ip A specific IP address or a range specified using IP/netmask like 192.168.1.0/24
      */
-    public function matchIp($ip)
+    public function matchIp(string $ip)
     {
         $this->matchIps($ip);
     }
@@ -144,11 +140,8 @@ public function matchMethod($method)
 
     /**
      * Adds a check for request attribute.
-     *
-     * @param string $key    The request attribute name
-     * @param string $regexp A Regexp
      */
-    public function matchAttribute($key, $regexp)
+    public function matchAttribute(string $key, string $regexp)
     {
         $this->attributes[$key] = $regexp;
     }
diff --git a/src/Symfony/Component/HttpFoundation/Response.php b/src/Symfony/Component/HttpFoundation/Response.php
index 929fac4727bd0..6c69b9536d50e 100644
--- a/src/Symfony/Component/HttpFoundation/Response.php
+++ b/src/Symfony/Component/HttpFoundation/Response.php
@@ -191,7 +191,7 @@ class Response
     /**
      * @throws \InvalidArgumentException When the HTTP status code is not valid
      */
-    public function __construct($content = '', int $status = 200, array $headers = [])
+    public function __construct(?string $content = '', int $status = 200, array $headers = [])
     {
         $this->headers = new ResponseHeaderBag($headers);
         $this->setContent($content);
@@ -207,13 +207,9 @@ public function __construct($content = '', int $status = 200, array $headers = [
      *     return Response::create($body, 200)
      *         ->setSharedMaxAge(300);
      *
-     * @param mixed $content The response content, see setContent()
-     * @param int   $status  The response status code
-     * @param array $headers An array of response headers
-     *
      * @return static
      */
-    public static function create($content = '', $status = 200, $headers = [])
+    public static function create(?string $content = '', int $status = 200, array $headers = [])
     {
         return new static($content, $status, $headers);
     }
@@ -382,21 +378,13 @@ public function send()
     /**
      * Sets the response content.
      *
-     * Valid types are strings, numbers, null, and objects that implement a __toString() method.
-     *
-     * @param mixed $content Content that can be cast to string
-     *
      * @return $this
      *
      * @throws \UnexpectedValueException
      */
-    public function setContent($content)
+    public function setContent(?string $content)
     {
-        if (null !== $content && !\is_string($content) && !is_numeric($content) && !\is_callable([$content, '__toString'])) {
-            throw new \UnexpectedValueException(sprintf('The Response content must be a string or object implementing __toString(), "%s" given.', \gettype($content)));
-        }
-
-        $this->content = (string) $content;
+        $this->content = $content ?? '';
 
         return $this;
     }
diff --git a/src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php b/src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php
index 9d7163ebcc226..2abd3b6a174fe 100644
--- a/src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php
+++ b/src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php
@@ -108,7 +108,7 @@ public function all(string $key = null)
     /**
      * {@inheritdoc}
      */
-    public function set($key, $values, $replace = true)
+    public function set(string $key, $values, bool $replace = true)
     {
         $uniqueKey = str_replace('_', '-', strtolower($key));
 
@@ -139,7 +139,7 @@ public function set($key, $values, $replace = true)
     /**
      * {@inheritdoc}
      */
-    public function remove($key)
+    public function remove(string $key)
     {
         $uniqueKey = str_replace('_', '-', strtolower($key));
         unset($this->headerNames[$uniqueKey]);
@@ -164,7 +164,7 @@ public function remove($key)
     /**
      * {@inheritdoc}
      */
-    public function hasCacheControlDirective($key)
+    public function hasCacheControlDirective(string $key)
     {
         return \array_key_exists($key, $this->computedCacheControl);
     }
@@ -172,7 +172,7 @@ public function hasCacheControlDirective($key)
     /**
      * {@inheritdoc}
      */
-    public function getCacheControlDirective($key)
+    public function getCacheControlDirective(string $key)
     {
         return \array_key_exists($key, $this->computedCacheControl) ? $this->computedCacheControl[$key] : null;
     }
@@ -185,12 +185,8 @@ public function setCookie(Cookie $cookie)
 
     /**
      * Removes a cookie from the array, but does not unset it in the browser.
-     *
-     * @param string $name
-     * @param string $path
-     * @param string $domain
      */
-    public function removeCookie($name, $path = '/', $domain = null)
+    public function removeCookie(string $name, ?string $path = '/', string $domain = null)
     {
         if (null === $path) {
             $path = '/';
@@ -214,13 +210,11 @@ public function removeCookie($name, $path = '/', $domain = null)
     /**
      * Returns an array with all cookies.
      *
-     * @param string $format
-     *
      * @return Cookie[]
      *
      * @throws \InvalidArgumentException When the $format is invalid
      */
-    public function getCookies($format = self::COOKIES_FLAT)
+    public function getCookies(string $format = self::COOKIES_FLAT)
     {
         if (!\in_array($format, [self::COOKIES_FLAT, self::COOKIES_ARRAY])) {
             throw new \InvalidArgumentException(sprintf('Format "%s" invalid (%s).', $format, implode(', ', [self::COOKIES_FLAT, self::COOKIES_ARRAY])));
@@ -244,14 +238,8 @@ public function getCookies($format = self::COOKIES_FLAT)
 
     /**
      * Clears a cookie in the browser.
-     *
-     * @param string $name
-     * @param string $path
-     * @param string $domain
-     * @param bool   $secure
-     * @param bool   $httpOnly
      */
-    public function clearCookie($name, $path = '/', $domain = null, $secure = false, $httpOnly = true)
+    public function clearCookie(string $name, ?string $path = '/', string $domain = null, bool $secure = false, bool $httpOnly = true)
     {
         $this->setCookie(new Cookie($name, null, 1, $path, $domain, $secure, $httpOnly, false, null));
     }
@@ -259,9 +247,9 @@ public function clearCookie($name, $path = '/', $domain = null, $secure = false,
     /**
      * @see HeaderUtils::makeDisposition()
      */
-    public function makeDisposition($disposition, $filename, $filenameFallback = '')
+    public function makeDisposition(string $disposition, string $filename, string $filenameFallback = '')
     {
-        return HeaderUtils::makeDisposition((string) $disposition, (string) $filename, (string) $filenameFallback);
+        return HeaderUtils::makeDisposition($disposition, $filename, $filenameFallback);
     }
 
     /**
diff --git a/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBag.php b/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBag.php
index ee33698cf0842..aad6b610e7bb3 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBag.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBag.php
@@ -37,7 +37,7 @@ public function getName()
         return $this->name;
     }
 
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
@@ -61,7 +61,7 @@ public function getStorageKey()
     /**
      * {@inheritdoc}
      */
-    public function has($name)
+    public function has(string $name)
     {
         return \array_key_exists($name, $this->attributes);
     }
@@ -69,7 +69,7 @@ public function has($name)
     /**
      * {@inheritdoc}
      */
-    public function get($name, $default = null)
+    public function get(string $name, $default = null)
     {
         return \array_key_exists($name, $this->attributes) ? $this->attributes[$name] : $default;
     }
@@ -77,7 +77,7 @@ public function get($name, $default = null)
     /**
      * {@inheritdoc}
      */
-    public function set($name, $value)
+    public function set(string $name, $value)
     {
         $this->attributes[$name] = $value;
     }
@@ -104,7 +104,7 @@ public function replace(array $attributes)
     /**
      * {@inheritdoc}
      */
-    public function remove($name)
+    public function remove(string $name)
     {
         $retval = null;
         if (\array_key_exists($name, $this->attributes)) {
diff --git a/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBagInterface.php b/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBagInterface.php
index 6fa2293970b90..7017b717e4064 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBagInterface.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Attribute/AttributeBagInterface.php
@@ -23,29 +23,25 @@ interface AttributeBagInterface extends SessionBagInterface
     /**
      * Checks if an attribute is defined.
      *
-     * @param string $name The attribute name
-     *
      * @return bool true if the attribute is defined, false otherwise
      */
-    public function has($name);
+    public function has(string $name);
 
     /**
      * Returns an attribute.
      *
-     * @param string $name    The attribute name
-     * @param mixed  $default The default value if not found
+     * @param mixed $default The default value if not found
      *
      * @return mixed
      */
-    public function get($name, $default = null);
+    public function get(string $name, $default = null);
 
     /**
      * Sets an attribute.
      *
-     * @param string $name
-     * @param mixed  $value
+     * @param mixed $value
      */
-    public function set($name, $value);
+    public function set(string $name, $value);
 
     /**
      * Returns attributes.
@@ -59,9 +55,7 @@ public function replace(array $attributes);
     /**
      * Removes an attribute.
      *
-     * @param string $name
-     *
      * @return mixed The removed value or null when it does not exist
      */
-    public function remove($name);
+    public function remove(string $name);
 }
diff --git a/src/Symfony/Component/HttpFoundation/Session/Attribute/NamespacedAttributeBag.php b/src/Symfony/Component/HttpFoundation/Session/Attribute/NamespacedAttributeBag.php
index 162c4b5295849..0c4690f4b74ca 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Attribute/NamespacedAttributeBag.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Attribute/NamespacedAttributeBag.php
@@ -34,7 +34,7 @@ public function __construct(string $storageKey = '_sf2_attributes', string $name
     /**
      * {@inheritdoc}
      */
-    public function has($name)
+    public function has(string $name)
     {
         // reference mismatch: if fixed, re-introduced in array_key_exists; keep as it is
         $attributes = $this->resolveAttributePath($name);
@@ -50,7 +50,7 @@ public function has($name)
     /**
      * {@inheritdoc}
      */
-    public function get($name, $default = null)
+    public function get(string $name, $default = null)
     {
         // reference mismatch: if fixed, re-introduced in array_key_exists; keep as it is
         $attributes = $this->resolveAttributePath($name);
@@ -66,7 +66,7 @@ public function get($name, $default = null)
     /**
      * {@inheritdoc}
      */
-    public function set($name, $value)
+    public function set(string $name, $value)
     {
         $attributes = &$this->resolveAttributePath($name, true);
         $name = $this->resolveKey($name);
@@ -76,7 +76,7 @@ public function set($name, $value)
     /**
      * {@inheritdoc}
      */
-    public function remove($name)
+    public function remove(string $name)
     {
         $retval = null;
         $attributes = &$this->resolveAttributePath($name);
@@ -99,7 +99,7 @@ public function remove($name)
      *
      * @return array
      */
-    protected function &resolveAttributePath($name, $writeContext = false)
+    protected function &resolveAttributePath(string $name, bool $writeContext = false)
     {
         $array = &$this->attributes;
         $name = (0 === strpos($name, $this->namespaceCharacter)) ? substr($name, 1) : $name;
@@ -144,11 +144,9 @@ protected function &resolveAttributePath($name, $writeContext = false)
      *
      * This is the last part in a dot separated string.
      *
-     * @param string $name
-     *
      * @return string
      */
-    protected function resolveKey($name)
+    protected function resolveKey(string $name)
     {
         if (false !== $pos = strrpos($name, $this->namespaceCharacter)) {
             $name = substr($name, $pos + 1);
diff --git a/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php b/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php
index 6502f3d50155f..2707d64ec7138 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php
@@ -38,7 +38,7 @@ public function getName()
         return $this->name;
     }
 
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
@@ -60,7 +60,7 @@ public function initialize(array &$flashes)
     /**
      * {@inheritdoc}
      */
-    public function add($type, $message)
+    public function add(string $type, $message)
     {
         $this->flashes['new'][$type][] = $message;
     }
@@ -68,7 +68,7 @@ public function add($type, $message)
     /**
      * {@inheritdoc}
      */
-    public function peek($type, array $default = [])
+    public function peek(string $type, array $default = [])
     {
         return $this->has($type) ? $this->flashes['display'][$type] : $default;
     }
@@ -84,7 +84,7 @@ public function peekAll()
     /**
      * {@inheritdoc}
      */
-    public function get($type, array $default = [])
+    public function get(string $type, array $default = [])
     {
         $return = $default;
 
@@ -122,7 +122,7 @@ public function setAll(array $messages)
     /**
      * {@inheritdoc}
      */
-    public function set($type, $messages)
+    public function set(string $type, $messages)
     {
         $this->flashes['new'][$type] = (array) $messages;
     }
@@ -130,7 +130,7 @@ public function set($type, $messages)
     /**
      * {@inheritdoc}
      */
-    public function has($type)
+    public function has(string $type)
     {
         return \array_key_exists($type, $this->flashes['display']) && $this->flashes['display'][$type];
     }
diff --git a/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBag.php b/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBag.php
index c6b7ce354cec4..88df7508ac689 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBag.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBag.php
@@ -38,7 +38,7 @@ public function getName()
         return $this->name;
     }
 
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
@@ -54,7 +54,7 @@ public function initialize(array &$flashes)
     /**
      * {@inheritdoc}
      */
-    public function add($type, $message)
+    public function add(string $type, $message)
     {
         $this->flashes[$type][] = $message;
     }
@@ -62,7 +62,7 @@ public function add($type, $message)
     /**
      * {@inheritdoc}
      */
-    public function peek($type, array $default = [])
+    public function peek(string $type, array $default = [])
     {
         return $this->has($type) ? $this->flashes[$type] : $default;
     }
@@ -78,7 +78,7 @@ public function peekAll()
     /**
      * {@inheritdoc}
      */
-    public function get($type, array $default = [])
+    public function get(string $type, array $default = [])
     {
         if (!$this->has($type)) {
             return $default;
@@ -105,7 +105,7 @@ public function all()
     /**
      * {@inheritdoc}
      */
-    public function set($type, $messages)
+    public function set(string $type, $messages)
     {
         $this->flashes[$type] = (array) $messages;
     }
@@ -121,7 +121,7 @@ public function setAll(array $messages)
     /**
      * {@inheritdoc}
      */
-    public function has($type)
+    public function has(string $type)
     {
         return \array_key_exists($type, $this->flashes) && $this->flashes[$type];
     }
diff --git a/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBagInterface.php b/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBagInterface.php
index 99e8074214b62..8713e71d0f62e 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBagInterface.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Flash/FlashBagInterface.php
@@ -23,18 +23,16 @@ interface FlashBagInterface extends SessionBagInterface
     /**
      * Adds a flash message for the given type.
      *
-     * @param string $type
-     * @param mixed  $message
+     * @param mixed $message
      */
-    public function add($type, $message);
+    public function add(string $type, $message);
 
     /**
      * Registers one or more messages for a given type.
      *
-     * @param string       $type
      * @param string|array $messages
      */
-    public function set($type, $messages);
+    public function set(string $type, $messages);
 
     /**
      * Gets flash messages for a given type.
@@ -44,7 +42,7 @@ public function set($type, $messages);
      *
      * @return array
      */
-    public function peek($type, array $default = []);
+    public function peek(string $type, array $default = []);
 
     /**
      * Gets all flash messages.
@@ -56,12 +54,11 @@ public function peekAll();
     /**
      * Gets and clears flash from the stack.
      *
-     * @param string $type
-     * @param array  $default Default value if $type does not exist
+     * @param array $default Default value if $type does not exist
      *
      * @return array
      */
-    public function get($type, array $default = []);
+    public function get(string $type, array $default = []);
 
     /**
      * Gets and clears flashes from the stack.
@@ -78,11 +75,9 @@ public function setAll(array $messages);
     /**
      * Has flash messages for a given type?
      *
-     * @param string $type
-     *
      * @return bool
      */
-    public function has($type);
+    public function has(string $type);
 
     /**
      * Returns a list of all defined types.
diff --git a/src/Symfony/Component/HttpFoundation/Session/Session.php b/src/Symfony/Component/HttpFoundation/Session/Session.php
index 365ef29cf0f8b..e55eb45eaf90f 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Session.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Session.php
@@ -55,7 +55,7 @@ public function start()
     /**
      * {@inheritdoc}
      */
-    public function has($name)
+    public function has(string $name)
     {
         return $this->getAttributeBag()->has($name);
     }
@@ -63,7 +63,7 @@ public function has($name)
     /**
      * {@inheritdoc}
      */
-    public function get($name, $default = null)
+    public function get(string $name, $default = null)
     {
         return $this->getAttributeBag()->get($name, $default);
     }
@@ -71,7 +71,7 @@ public function get($name, $default = null)
     /**
      * {@inheritdoc}
      */
-    public function set($name, $value)
+    public function set(string $name, $value)
     {
         $this->getAttributeBag()->set($name, $value);
     }
@@ -95,7 +95,7 @@ public function replace(array $attributes)
     /**
      * {@inheritdoc}
      */
-    public function remove($name)
+    public function remove(string $name)
     {
         return $this->getAttributeBag()->remove($name);
     }
@@ -168,7 +168,7 @@ public function isEmpty()
     /**
      * {@inheritdoc}
      */
-    public function invalidate($lifetime = null)
+    public function invalidate(int $lifetime = null)
     {
         $this->storage->clear();
 
@@ -178,7 +178,7 @@ public function invalidate($lifetime = null)
     /**
      * {@inheritdoc}
      */
-    public function migrate($destroy = false, $lifetime = null)
+    public function migrate(bool $destroy = false, int $lifetime = null)
     {
         return $this->storage->regenerate($destroy, $lifetime);
     }
@@ -202,7 +202,7 @@ public function getId()
     /**
      * {@inheritdoc}
      */
-    public function setId($id)
+    public function setId(string $id)
     {
         if ($this->storage->getId() !== $id) {
             $this->storage->setId($id);
@@ -220,7 +220,7 @@ public function getName()
     /**
      * {@inheritdoc}
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->storage->setName($name);
     }
@@ -246,7 +246,7 @@ public function registerBag(SessionBagInterface $bag)
     /**
      * {@inheritdoc}
      */
-    public function getBag($name)
+    public function getBag(string $name)
     {
         $bag = $this->storage->getBag($name);
 
diff --git a/src/Symfony/Component/HttpFoundation/Session/SessionInterface.php b/src/Symfony/Component/HttpFoundation/Session/SessionInterface.php
index e758c6bda6018..b2f09fd0dc713 100644
--- a/src/Symfony/Component/HttpFoundation/Session/SessionInterface.php
+++ b/src/Symfony/Component/HttpFoundation/Session/SessionInterface.php
@@ -38,10 +38,8 @@ public function getId();
 
     /**
      * Sets the session ID.
-     *
-     * @param string $id
      */
-    public function setId($id);
+    public function setId(string $id);
 
     /**
      * Returns the session name.
@@ -52,10 +50,8 @@ public function getName();
 
     /**
      * Sets the session name.
-     *
-     * @param string $name
      */
-    public function setName($name);
+    public function setName(string $name);
 
     /**
      * Invalidates the current session.
@@ -70,7 +66,7 @@ public function setName($name);
      *
      * @return bool
      */
-    public function invalidate($lifetime = null);
+    public function invalidate(int $lifetime = null);
 
     /**
      * Migrates the current session to a new session id while maintaining all
@@ -84,7 +80,7 @@ public function invalidate($lifetime = null);
      *
      * @return bool
      */
-    public function migrate($destroy = false, $lifetime = null);
+    public function migrate(bool $destroy = false, int $lifetime = null);
 
     /**
      * Force the session to be saved and closed.
@@ -98,29 +94,25 @@ public function save();
     /**
      * Checks if an attribute is defined.
      *
-     * @param string $name The attribute name
-     *
      * @return bool
      */
-    public function has($name);
+    public function has(string $name);
 
     /**
      * Returns an attribute.
      *
-     * @param string $name    The attribute name
-     * @param mixed  $default The default value if not found
+     * @param mixed $default The default value if not found
      *
      * @return mixed
      */
-    public function get($name, $default = null);
+    public function get(string $name, $default = null);
 
     /**
      * Sets an attribute.
      *
-     * @param string $name
-     * @param mixed  $value
+     * @param mixed $value
      */
-    public function set($name, $value);
+    public function set(string $name, $value);
 
     /**
      * Returns attributes.
@@ -137,11 +129,9 @@ public function replace(array $attributes);
     /**
      * Removes an attribute.
      *
-     * @param string $name
-     *
      * @return mixed The removed value or null when it does not exist
      */
-    public function remove($name);
+    public function remove(string $name);
 
     /**
      * Clears all attributes.
@@ -163,11 +153,9 @@ public function registerBag(SessionBagInterface $bag);
     /**
      * Gets a bag instance by name.
      *
-     * @param string $name
-     *
      * @return SessionBagInterface
      */
-    public function getBag($name);
+    public function getBag(string $name);
 
     /**
      * Gets session meta.
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/AbstractSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/AbstractSessionHandler.php
index 78340efbd2228..9594c0ac42460 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/AbstractSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/AbstractSessionHandler.php
@@ -42,26 +42,19 @@ public function open($savePath, $sessionName)
     }
 
     /**
-     * @param string $sessionId
-     *
      * @return string
      */
-    abstract protected function doRead($sessionId);
+    abstract protected function doRead(string $sessionId);
 
     /**
-     * @param string $sessionId
-     * @param string $data
-     *
      * @return bool
      */
-    abstract protected function doWrite($sessionId, $data);
+    abstract protected function doWrite(string $sessionId, string $data);
 
     /**
-     * @param string $sessionId
-     *
      * @return bool
      */
-    abstract protected function doDestroy($sessionId);
+    abstract protected function doDestroy(string $sessionId);
 
     /**
      * {@inheritdoc}
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MemcachedSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MemcachedSessionHandler.php
index 3faa336f69dd6..6f5df61f4d87d 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MemcachedSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MemcachedSessionHandler.php
@@ -65,7 +65,7 @@ public function close()
     /**
      * {@inheritdoc}
      */
-    protected function doRead($sessionId)
+    protected function doRead(string $sessionId)
     {
         return $this->memcached->get($this->prefix.$sessionId) ?: '';
     }
@@ -83,7 +83,7 @@ public function updateTimestamp($sessionId, $data)
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data)
+    protected function doWrite(string $sessionId, string $data)
     {
         return $this->memcached->set($this->prefix.$sessionId, $data, time() + $this->ttl);
     }
@@ -91,7 +91,7 @@ protected function doWrite($sessionId, $data)
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId)
+    protected function doDestroy(string $sessionId)
     {
         $result = $this->memcached->delete($this->prefix.$sessionId);
 
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MongoDbSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MongoDbSessionHandler.php
index 53d9369e8d53b..7ee188acf6443 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MongoDbSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/MongoDbSessionHandler.php
@@ -90,7 +90,7 @@ public function close()
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId)
+    protected function doDestroy(string $sessionId)
     {
         $this->getCollection()->deleteOne([
             $this->options['id_field'] => $sessionId,
@@ -114,7 +114,7 @@ public function gc($maxlifetime)
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data)
+    protected function doWrite(string $sessionId, string $data)
     {
         $expiry = new \MongoDB\BSON\UTCDateTime((time() + (int) ini_get('session.gc_maxlifetime')) * 1000);
 
@@ -154,7 +154,7 @@ public function updateTimestamp($sessionId, $data)
     /**
      * {@inheritdoc}
      */
-    protected function doRead($sessionId)
+    protected function doRead(string $sessionId)
     {
         $dbData = $this->getCollection()->findOne([
             $this->options['id_field'] => $sessionId,
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/NullSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/NullSessionHandler.php
index 8d193155b090f..603b682378777 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/NullSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/NullSessionHandler.php
@@ -37,7 +37,7 @@ public function validateId($sessionId)
     /**
      * {@inheritdoc}
      */
-    protected function doRead($sessionId)
+    protected function doRead(string $sessionId)
     {
         return '';
     }
@@ -53,7 +53,7 @@ public function updateTimestamp($sessionId, $data)
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data)
+    protected function doWrite(string $sessionId, string $data)
     {
         return true;
     }
@@ -61,7 +61,7 @@ protected function doWrite($sessionId, $data)
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId)
+    protected function doDestroy(string $sessionId)
     {
         return true;
     }
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/PdoSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/PdoSessionHandler.php
index f1648adaa52e4..d8bb069edd8f1 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/PdoSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/PdoSessionHandler.php
@@ -299,7 +299,7 @@ public function gc($maxlifetime)
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId)
+    protected function doDestroy(string $sessionId)
     {
         // delete the record associated with this id
         $sql = "DELETE FROM $this->table WHERE $this->idCol = :id";
@@ -320,7 +320,7 @@ protected function doDestroy($sessionId)
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data)
+    protected function doWrite(string $sessionId, string $data)
     {
         $maxlifetime = (int) ini_get('session.gc_maxlifetime');
 
@@ -596,11 +596,9 @@ private function rollback(): void
      * We need to make sure we do not return session data that is already considered garbage according
      * to the session.gc_maxlifetime setting because gc() is called after read() and only sometimes.
      *
-     * @param string $sessionId Session ID
-     *
-     * @return string The session data
+     * @return string
      */
-    protected function doRead($sessionId)
+    protected function doRead(string $sessionId)
     {
         if (self::LOCK_ADVISORY === $this->lockMode) {
             $this->unlockStatements[] = $this->doAdvisoryLock($sessionId);
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/RedisSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/RedisSessionHandler.php
index c2e7d34dcfe09..38727fb536750 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/RedisSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/RedisSessionHandler.php
@@ -62,7 +62,7 @@ public function __construct($redis, array $options = [])
     /**
      * {@inheritdoc}
      */
-    protected function doRead($sessionId): string
+    protected function doRead(string $sessionId): string
     {
         return $this->redis->get($this->prefix.$sessionId) ?: '';
     }
@@ -70,7 +70,7 @@ protected function doRead($sessionId): string
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data): bool
+    protected function doWrite(string $sessionId, string $data): bool
     {
         $result = $this->redis->setEx($this->prefix.$sessionId, (int) ini_get('session.gc_maxlifetime'), $data);
 
@@ -80,7 +80,7 @@ protected function doWrite($sessionId, $data): bool
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId): bool
+    protected function doDestroy(string $sessionId): bool
     {
         $this->redis->del($this->prefix.$sessionId);
 
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/StrictSessionHandler.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/StrictSessionHandler.php
index 83a1f2c063c05..07559fa234cd0 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/StrictSessionHandler.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Handler/StrictSessionHandler.php
@@ -43,7 +43,7 @@ public function open($savePath, $sessionName)
     /**
      * {@inheritdoc}
      */
-    protected function doRead($sessionId)
+    protected function doRead(string $sessionId)
     {
         return $this->handler->read($sessionId);
     }
@@ -59,7 +59,7 @@ public function updateTimestamp($sessionId, $data)
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data)
+    protected function doWrite(string $sessionId, string $data)
     {
         return $this->handler->write($sessionId, $data);
     }
@@ -78,7 +78,7 @@ public function destroy($sessionId)
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId)
+    protected function doDestroy(string $sessionId)
     {
         $this->doDestroy = false;
 
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/MetadataBag.php b/src/Symfony/Component/HttpFoundation/Session/Storage/MetadataBag.php
index 5fe40fc106183..c79ee023c4e50 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/MetadataBag.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/MetadataBag.php
@@ -100,7 +100,7 @@ public function getLifetime()
      *                      to expire with browser session. Time is in seconds, and is
      *                      not a Unix timestamp.
      */
-    public function stampNew($lifetime = null)
+    public function stampNew(int $lifetime = null)
     {
         $this->stampCreated($lifetime);
     }
@@ -151,10 +151,8 @@ public function getName()
 
     /**
      * Sets name.
-     *
-     * @param string $name
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/MockArraySessionStorage.php b/src/Symfony/Component/HttpFoundation/Session/Storage/MockArraySessionStorage.php
index 37b6f145b87cc..4662bd864c944 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/MockArraySessionStorage.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/MockArraySessionStorage.php
@@ -94,7 +94,7 @@ public function start()
     /**
      * {@inheritdoc}
      */
-    public function regenerate($destroy = false, $lifetime = null)
+    public function regenerate(bool $destroy = false, int $lifetime = null)
     {
         if (!$this->started) {
             $this->start();
@@ -117,7 +117,7 @@ public function getId()
     /**
      * {@inheritdoc}
      */
-    public function setId($id)
+    public function setId(string $id)
     {
         if ($this->started) {
             throw new \LogicException('Cannot set session ID after the session has started.');
@@ -137,7 +137,7 @@ public function getName()
     /**
      * {@inheritdoc}
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
@@ -183,7 +183,7 @@ public function registerBag(SessionBagInterface $bag)
     /**
      * {@inheritdoc}
      */
-    public function getBag($name)
+    public function getBag(string $name)
     {
         if (!isset($this->bags[$name])) {
             throw new \InvalidArgumentException(sprintf('The SessionBagInterface %s is not registered.', $name));
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php b/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
index 02fe4dad48dd6..019a63484e2e7 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
@@ -28,7 +28,6 @@ class MockFileSessionStorage extends MockArraySessionStorage
 
     /**
      * @param string $savePath Path of directory to save session files
-     * @param string $name     Session name
      */
     public function __construct(string $savePath = null, string $name = 'MOCKSESSID', MetadataBag $metaBag = null)
     {
@@ -68,7 +67,7 @@ public function start()
     /**
      * {@inheritdoc}
      */
-    public function regenerate($destroy = false, $lifetime = null)
+    public function regenerate(bool $destroy = false, int $lifetime = null)
     {
         if (!$this->started) {
             $this->start();
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php b/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php
index 2a57e6ce8801b..ed4c11d920a3c 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php
@@ -175,7 +175,7 @@ public function getId()
     /**
      * {@inheritdoc}
      */
-    public function setId($id)
+    public function setId(string $id)
     {
         $this->saveHandler->setId($id);
     }
@@ -191,7 +191,7 @@ public function getName()
     /**
      * {@inheritdoc}
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->saveHandler->setName($name);
     }
@@ -199,7 +199,7 @@ public function setName($name)
     /**
      * {@inheritdoc}
      */
-    public function regenerate($destroy = false, $lifetime = null)
+    public function regenerate(bool $destroy = false, int $lifetime = null)
     {
         // Cannot regenerate the session ID for non-active sessions.
         if (\PHP_SESSION_ACTIVE !== session_status()) {
@@ -308,7 +308,7 @@ public function registerBag(SessionBagInterface $bag)
     /**
      * {@inheritdoc}
      */
-    public function getBag($name)
+    public function getBag(string $name)
     {
         if (!isset($this->bags[$name])) {
             throw new \InvalidArgumentException(sprintf('The SessionBagInterface %s is not registered.', $name));
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php b/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php
index 09c92483c7575..cc6a5527726a2 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/Proxy/AbstractProxy.php
@@ -81,11 +81,9 @@ public function getId()
     /**
      * Sets the session ID.
      *
-     * @param string $id
-     *
      * @throws \LogicException
      */
-    public function setId($id)
+    public function setId(string $id)
     {
         if ($this->isActive()) {
             throw new \LogicException('Cannot change the ID of an active session');
@@ -107,11 +105,9 @@ public function getName()
     /**
      * Sets the session name.
      *
-     * @param string $name
-     *
      * @throws \LogicException
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         if ($this->isActive()) {
             throw new \LogicException('Cannot change the name of an active session');
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/SessionStorageInterface.php b/src/Symfony/Component/HttpFoundation/Session/Storage/SessionStorageInterface.php
index eeb396a2f131c..eb8e8ff2357e5 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/SessionStorageInterface.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/SessionStorageInterface.php
@@ -46,24 +46,20 @@ public function getId();
 
     /**
      * Sets the session ID.
-     *
-     * @param string $id
      */
-    public function setId($id);
+    public function setId(string $id);
 
     /**
      * Returns the session name.
      *
-     * @return mixed The session name
+     * @return string The session name
      */
     public function getName();
 
     /**
      * Sets the session name.
-     *
-     * @param string $name
      */
-    public function setName($name);
+    public function setName(string $name);
 
     /**
      * Regenerates id that represents this storage.
@@ -94,7 +90,7 @@ public function setName($name);
      *
      * @throws \RuntimeException If an error occurs while regenerating this storage
      */
-    public function regenerate($destroy = false, $lifetime = null);
+    public function regenerate(bool $destroy = false, int $lifetime = null);
 
     /**
      * Force the session to be saved and closed.
@@ -117,13 +113,11 @@ public function clear();
     /**
      * Gets a SessionBagInterface by name.
      *
-     * @param string $name
-     *
      * @return SessionBagInterface
      *
      * @throws \InvalidArgumentException If the bag does not exist
      */
-    public function getBag($name);
+    public function getBag(string $name);
 
     /**
      * Registers a SessionBagInterface for use.
diff --git a/src/Symfony/Component/HttpFoundation/StreamedResponse.php b/src/Symfony/Component/HttpFoundation/StreamedResponse.php
index 06d7a47ad8bcd..c21591be66957 100644
--- a/src/Symfony/Component/HttpFoundation/StreamedResponse.php
+++ b/src/Symfony/Component/HttpFoundation/StreamedResponse.php
@@ -30,11 +30,6 @@ class StreamedResponse extends Response
     protected $streamed;
     private $headersSent;
 
-    /**
-     * @param callable|null $callback A valid PHP callback or null to set it later
-     * @param int           $status   The response status code
-     * @param array         $headers  An array of response headers
-     */
     public function __construct(callable $callback = null, int $status = 200, array $headers = [])
     {
         parent::__construct(null, $status, $headers);
@@ -50,12 +45,10 @@ public function __construct(callable $callback = null, int $status = 200, array
      * Factory method for chainability.
      *
      * @param callable|null $callback A valid PHP callback or null to set it later
-     * @param int           $status   The response status code
-     * @param array         $headers  An array of response headers
      *
      * @return static
      */
-    public static function create($callback = null, $status = 200, $headers = [])
+    public static function create($callback = null, int $status = 200, array $headers = [])
     {
         return new static($callback, $status, $headers);
     }
@@ -121,7 +114,7 @@ public function sendContent()
      *
      * @return $this
      */
-    public function setContent($content)
+    public function setContent(?string $content)
     {
         if (null !== $content) {
             throw new \LogicException('The content cannot be set on a StreamedResponse instance.');
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RedirectResponseTest.php b/src/Symfony/Component/HttpFoundation/Tests/RedirectResponseTest.php
index 4e28b9ac97261..54c4fdaa07df6 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RedirectResponseTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RedirectResponseTest.php
@@ -62,13 +62,6 @@ public function testSetTargetUrl()
         $this->assertEquals('baz.beep', $response->getTargetUrl());
     }
 
-    public function testSetTargetUrlNull()
-    {
-        $this->expectException('InvalidArgumentException');
-        $response = new RedirectResponse('foo.bar');
-        $response->setTargetUrl(null);
-    }
-
     public function testCreate()
     {
         $response = RedirectResponse::create('foo', 301);
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
index 4a009903a947f..38454667bf88e 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -426,7 +426,7 @@ public function testGetPreferredFormat()
     }
 
     /**
-     * @dataProvider getFormatToMimeTypeMapProviderWithAdditionalNullFormat
+     * @dataProvider getFormatToMimeTypeMapProvider
      */
     public function testGetFormatFromMimeType($format, $mimeTypes)
     {
@@ -444,14 +444,6 @@ public function testGetFormatFromMimeType($format, $mimeTypes)
         }
     }
 
-    public function getFormatToMimeTypeMapProviderWithAdditionalNullFormat()
-    {
-        return array_merge(
-            [[null, [null, 'unexistent-mime-type']]],
-            $this->getFormatToMimeTypeMapProvider()
-        );
-    }
-
     public function testGetFormatFromMimeTypeWithParameters()
     {
         $request = new Request();
diff --git a/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php b/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
index 03b29653e8831..2feac9b892763 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
@@ -900,16 +900,6 @@ public function testSetContent($content)
         $this->assertEquals((string) $content, $response->getContent());
     }
 
-    /**
-     * @dataProvider invalidContentProvider
-     */
-    public function testSetContentInvalid($content)
-    {
-        $this->expectException('UnexpectedValueException');
-        $response = new Response();
-        $response->setContent($content);
-    }
-
     public function testSettersAreChainable()
     {
         $response = new Response();
@@ -951,15 +941,6 @@ public function validContentProvider()
         ];
     }
 
-    public function invalidContentProvider()
-    {
-        return [
-            'obj' => [new \stdClass()],
-            'array' => [[]],
-            'bool' => [true, '1'],
-        ];
-    }
-
     protected function createDateTimeOneHourAgo()
     {
         return $this->createDateTimeNow()->sub(new \DateInterval('PT1H'));
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Session/Storage/NativeSessionStorageTest.php b/src/Symfony/Component/HttpFoundation/Tests/Session/Storage/NativeSessionStorageTest.php
index 17f46bef5e1a1..c846248adc6d8 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Session/Storage/NativeSessionStorageTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Session/Storage/NativeSessionStorageTest.php
@@ -199,13 +199,6 @@ public function testSessionOptions()
         $this->assertSame('200', ini_get('session.cache_expire'));
     }
 
-    public function testSetSaveHandlerException()
-    {
-        $this->expectException('InvalidArgumentException');
-        $storage = $this->getStorage();
-        $storage->setSaveHandler(new \stdClass());
-    }
-
     public function testSetSaveHandler()
     {
         $this->iniSet('session.save_handler', 'files');