diff --git a/.travis.yml b/.travis.yml
index 98f53e5ca2..4cafa1a4b5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,6 +8,7 @@ env:
   global:
     - COMPOSER_ARGS="--no-interaction"
     - COVERAGE_DEPS="php-coveralls/php-coveralls"
+    - PHPSTAN_DEPS="phpstan/phpstan:^0.12"
     - TESTS_ZEND_HTTP_CLIENT_ONLINE=true
     - TESTS_ZEND_HTTP_CLIENT_BASEURI=http://127.0.0.1
     - TESTS_ZEND_HTTP_CLIENT_HTTP_PROXY=127.0.0.1:8081
@@ -43,6 +44,7 @@ matrix:
         - DEPS=locked
         - CS_CHECK=true
         - TEST_COVERAGE=true
+        - PHPSTAN_TEST=true
     - php: 7.1
       env:
         - DEPS=latest
@@ -74,6 +76,7 @@ install:
   - if [[ $DEPS == 'latest' ]]; then travis_retry composer update $COMPOSER_ARGS ; fi
   - if [[ $DEPS == 'lowest' ]]; then travis_retry composer update --prefer-lowest --prefer-stable $COMPOSER_ARGS ; fi
   - if [[ $TEST_COVERAGE == 'true' ]]; then travis_retry composer require --dev $COMPOSER_ARGS $COVERAGE_DEPS ; fi
+  - if [[ $PHPSTAN_TEST == 'true' ]]; then travis_retry composer require --dev $COMPOSER_ARGS $PHPSTAN_DEPS ; fi
   - stty cols 120 && composer show
 
 before_script:
@@ -105,6 +108,7 @@ before_script:
 script:
   - if [[ $TEST_COVERAGE == 'true' ]]; then composer test-coverage ; else composer test ; fi
   - if [[ $CS_CHECK == 'true' ]]; then composer cs-check ; fi
+  - if [[ $PHPSTAN_TEST == 'true' ]]; then ./vendor/bin/phpstan analyse --no-progress . ; fi
 
 after_script:
   - if [[ $TEST_COVERAGE == 'true' ]]; then travis_retry php vendor/bin/php-coveralls -v ; fi
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a5067ee22..ad83663308 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,7 +10,10 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Changed
 
-- Nothing.
+- `Zend\Http\Request`'s URI now always have a default path ´/´ even when a `Zend\Uri\Http`
+  object is provided with no path.
+- Relative URIs are not allowed anymore in `Zend\Http\Client`.
+  Anyway, usage of relative URIs has no sense and no adapter can handle it.
 
 ### Deprecated
 
@@ -22,7 +25,9 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Fixed
 
-- Nothing.
+- Fixed `Zend\Http\Cookies::getAllCookies(Zend\Http\Cookies::COOKIE_STRING_ARRAY)`.
+- Fixed `Zend\Http\Cookies::getAllCookies(Zend\Http\Cookies::COOKIE_STRING_CONCAT)`.
+- Fixed use of HTTP URIs with empty path in Request
 
 ## 2.11.1 - TBD
 
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
new file mode 100644
index 0000000000..53728fdd73
--- /dev/null
+++ b/phpstan.neon.dist
@@ -0,0 +1,46 @@
+parameters:
+    level: max
+
+    excludes_analyse:
+        - %currentWorkingDirectory%/docs/*
+        - %currentWorkingDirectory%/test/*
+        - %currentWorkingDirectory%/vendor/*
+
+    universalObjectCratesClasses:
+        - Zend\Http\Header\Accept\FieldValuePart\AbstractFieldValuePart
+
+    ignoreErrors:
+        -
+            message: '#Else branch is unreachable because ternary operator condition is always true#'
+            path: %currentWorkingDirectory%/src/Response.php
+        -
+            message: '#Result of && is always false#'
+            path: %currentWorkingDirectory%/src/PhpEnvironment/Request.php
+        -
+            message: '#Parameter \#1 $port of method Zend\\Uri\\Uri::setPort\(\) expects int, int|null given#'
+            path: %currentWorkingDirectory%/src/PhpEnvironment/Request.php
+        -
+            message: '#Result of && is always false#'
+            path: %currentWorkingDirectory%/src/Headers.php
+        -
+            message: '#Parameter \#1 \$fragment of method Zend\\Uri\\UriInterface::setFragment\(\) expects string, null given#'
+            path: %currentWorkingDirectory%/src/Header/Referer.php
+        -
+            message: '#Strict comparison using === between DateTime|string and 0 will always evaluate to false#'
+            path: %currentWorkingDirectory%/src/Header/Expires.php
+        -
+            message: '#Return type \(int\) of method Zend\\Http\\Header\\Age::getFieldValue\(\) should be compatible with return type \(string\) of method Zend\\Http\\Header\\HeaderInterface::getFieldValue\(\)#'
+            path: %currentWorkingDirectory%/src/Header/Age.php
+        -
+            message: '#Result of && is always false#'
+            path: %currentWorkingDirectory%/src/Header/Age.php
+        -
+            message: '#Access to an undefined property object::\$params#'
+            path: %currentWorkingDirectory%/src/Header/AbstractAccept.php
+        -
+            message: '#Negated boolean expression is always false#'
+            path: %currentWorkingDirectory%/src/Client/Adapter/Curl.php
+        -
+            message: '#Else branch is unreachable because previous condition is always true#'
+            path: %currentWorkingDirectory%/src/Client.php
+        - '#Access to an undefined property object::\$.+#'
diff --git a/src/AbstractMessage.php b/src/AbstractMessage.php
index 3ee1d51adc..73b79df8f7 100644
--- a/src/AbstractMessage.php
+++ b/src/AbstractMessage.php
@@ -30,7 +30,7 @@ abstract class AbstractMessage extends Message
     protected $version = self::VERSION_11;
 
     /**
-     * @var Headers|null
+     * @var Headers|string|null
      */
     protected $headers;
 
diff --git a/src/Client.php b/src/Client.php
index 7626f7756e..5a0b43a0cd 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -11,6 +11,11 @@
 use Traversable;
 use Zend\Http\Client\Adapter\Curl;
 use Zend\Http\Client\Adapter\Socket;
+use Zend\Http\Client\Adapter\StreamInterface;
+use Zend\Http\Exception\InvalidArgumentException;
+use Zend\Http\Exception\RuntimeException;
+use Zend\Http\Exception\UnexpectedValueException;
+use Zend\Http\Header\HeaderInterface;
 use Zend\Http\Header\SetCookie;
 use Zend\Stdlib;
 use Zend\Stdlib\ArrayUtils;
@@ -45,17 +50,17 @@ class Client implements Stdlib\DispatchableInterface
     const DIGEST_CNONCE = 'cnonce';
 
     /**
-     * @var Response
+     * @var null|Response
      */
     protected $response;
 
     /**
-     * @var Request
+     * @var null|Request
      */
     protected $request;
 
     /**
-     * @var Client\Adapter\AdapterInterface
+     * @var null|Client\Adapter\AdapterInterface
      */
     protected $adapter;
 
@@ -65,14 +70,14 @@ class Client implements Stdlib\DispatchableInterface
     protected $auth = [];
 
     /**
-     * @var string
+     * @var null|string|resource
      */
     protected $streamName;
 
     /**
      * @var resource|null
      */
-    protected $streamHandle = null;
+    protected $streamHandle;
 
     /**
      * @var array of Header\SetCookie
@@ -85,12 +90,12 @@ class Client implements Stdlib\DispatchableInterface
     protected $encType = '';
 
     /**
-     * @var Request
+     * @var null|string
      */
     protected $lastRawRequest;
 
     /**
-     * @var Response
+     * @var null|string
      */
     protected $lastRawResponse;
 
@@ -128,15 +133,15 @@ class Client implements Stdlib\DispatchableInterface
      * This variable is populated the first time _detectFileMimeType is called
      * and is then reused on every call to this method
      *
-     * @var resource
+     * @var null|resource
      */
     protected static $fileInfoDb;
 
     /**
      * Constructor
      *
-     * @param string $uri
-     * @param array|Traversable $options
+     * @param null|string $uri
+     * @param null|array|Traversable $options
      */
     public function __construct($uri = null, $options = null)
     {
@@ -170,9 +175,7 @@ public function setOptions($options = [])
         }
 
         // Pass configuration options to the adapter if it exists
-        if ($this->adapter instanceof Client\Adapter\AdapterInterface) {
-            $this->adapter->setOptions($options);
-        }
+        $this->getAdapter()->setOptions($options);
 
         return $this;
     }
@@ -203,9 +206,12 @@ public function setAdapter($adapter)
         }
 
         $this->adapter = $adapter;
+
         $config = $this->config;
         unset($config['adapter']);
-        $this->adapter->setOptions($config);
+
+        $adapter->setOptions($config);
+
         return $this;
     }
 
@@ -220,7 +226,10 @@ public function getAdapter()
             $this->setAdapter($this->config['adapter']);
         }
 
-        return $this->adapter;
+        /** @var Client\Adapter\AdapterInterface $adapter */
+        $adapter = $this->adapter;
+
+        return $adapter;
     }
 
     /**
@@ -277,7 +286,7 @@ public function getResponse()
     /**
      * Get the last request (as a string)
      *
-     * @return string
+     * @return null|string
      */
     public function getLastRawRequest()
     {
@@ -287,7 +296,7 @@ public function getLastRawRequest()
     /**
      * Get the last response (as a string)
      *
-     * @return string
+     * @return null|string
      */
     public function getLastRawResponse()
     {
@@ -314,13 +323,18 @@ public function setUri($uri)
     {
         if (! empty($uri)) {
             // remember host of last request
-            $lastHost = $this->getRequest()->getUri()->getHost();
+            $lastHost = $this->getRequest()->getUri()->getHost() ?: '';
             $this->getRequest()->setUri($uri);
 
             // if host changed, the HTTP authentication should be cleared for security
             // reasons, see #4215 for a discussion - currently authentication is also
             // cleared for peer subdomains due to technical limits
             $nextHost = $this->getRequest()->getUri()->getHost();
+
+            if (! $nextHost) {
+                throw new InvalidArgumentException('Relative URIs are not allowed');
+            }
+
             if (! preg_match('/' . preg_quote($lastHost, '/') . '$/i', $nextHost)) {
                 $this->clearAuth();
             }
@@ -412,7 +426,7 @@ public function getArgSeparator()
     {
         $argSeparator = $this->config['argseparator'];
         if (empty($argSeparator)) {
-            $argSeparator = ini_get('arg_separator.output');
+            $argSeparator = ini_get('arg_separator.output') ?: '&';
             $this->setArgSeparator($argSeparator);
         }
         return $argSeparator;
@@ -421,14 +435,14 @@ public function getArgSeparator()
     /**
      * Set the encoding type and the boundary (if any)
      *
-     * @param string $encType
-     * @param string $boundary
+     * @param null|string $encType
+     * @param null|string $boundary
      * @return $this
      */
     public function setEncType($encType, $boundary = null)
     {
         if (null === $encType || empty($encType)) {
-            $this->encType = null;
+            $this->encType = '';
             return $this;
         }
 
@@ -490,10 +504,9 @@ public function setParameterGet(array $query)
      * Reset all the HTTP parameters (request, response, etc)
      *
      * @param  bool   $clearCookies  Also clear all valid cookies? (defaults to false)
-     * @param  bool   $clearAuth     Also clear http authentication? (defaults to true)
      * @return $this
      */
-    public function resetParameters($clearCookies = false /*, $clearAuth = true */)
+    public function resetParameters($clearCookies = false)
     {
         $clearAuth = true;
         if (func_num_args() > 1) {
@@ -503,7 +516,7 @@ public function resetParameters($clearCookies = false /*, $clearAuth = true */)
         $uri = $this->getUri();
 
         $this->streamName      = null;
-        $this->encType         = null;
+        $this->encType         = '';
         $this->request         = null;
         $this->response        = null;
         $this->lastRawRequest  = null;
@@ -535,12 +548,12 @@ public function getCookies()
     /**
      * Get the cookie Id (name+domain+path)
      *
-     * @param  Header\SetCookie|Header\Cookie $cookie
+     * @param  Header\SetCookie $cookie
      * @return string|bool
      */
     protected function getCookieId($cookie)
     {
-        if (($cookie instanceof Header\SetCookie) || ($cookie instanceof Header\Cookie)) {
+        if ($cookie instanceof Header\SetCookie) {
             return $cookie->getName() . $cookie->getDomain() . $cookie->getPath();
         }
         return false;
@@ -550,14 +563,14 @@ protected function getCookieId($cookie)
      * Add a cookie
      *
      * @param array|ArrayIterator|Header\SetCookie|string $cookie
-     * @param string  $value
-     * @param string  $expire
-     * @param string  $path
-     * @param string  $domain
-     * @param  bool $secure
-     * @param  bool $httponly
-     * @param string  $maxAge
-     * @param string  $version
+     * @param null|string  $value
+     * @param null|string  $expire
+     * @param null|string  $path
+     * @param null|string  $domain
+     * @param bool $secure
+     * @param bool $httponly
+     * @param null|int  $maxAge
+     * @param null|int  $version
      * @throws Exception\InvalidArgumentException
      * @return $this
      */
@@ -681,12 +694,16 @@ public function getHeader($name)
     {
         $headers = $this->getRequest()->getHeaders();
 
-        if ($headers instanceof Headers) {
-            if ($headers->get($name)) {
-                return $headers->get($name)->getFieldValue();
-            }
+        if (! $headers instanceof Headers) {
+            return false;
         }
-        return false;
+
+        $header = $headers->get($name);
+        if (! $header instanceof HeaderInterface) {
+            return false;
+        }
+
+        return $header->getFieldValue();
     }
 
     /**
@@ -703,7 +720,7 @@ public function setStream($streamfile = true)
 
     /**
      * Get status of streaming for received data
-     * @return bool|string
+     * @return bool|resource|string
      */
     public function getStream()
     {
@@ -729,17 +746,20 @@ protected function openTempStream()
             $this->streamName = tempnam(
                 isset($this->config['streamtmpdir']) ? $this->config['streamtmpdir'] : sys_get_temp_dir(),
                 Client::class
-            );
+            ) ?: null;
         }
 
+        /** @var string streamName */
+        $streamName = $this->streamName;
+
         ErrorHandler::start();
-        $fp    = fopen($this->streamName, 'w+b');
+        $fp    = fopen($streamName, 'w+b');
         $error = ErrorHandler::stop();
         if (false === $fp) {
             if ($this->adapter instanceof Client\Adapter\AdapterInterface) {
                 $this->adapter->close();
             }
-            throw new Exception\RuntimeException(sprintf('Could not open temp file %s', $this->streamName), 0, $error);
+            throw new Exception\RuntimeException(sprintf('Could not open temp file %s', $streamName), 0, $error);
         }
 
         return $fp;
@@ -792,7 +812,7 @@ public function clearAuth()
      * @param string $user
      * @param string $password
      * @param string $type
-     * @param array $digest
+     * @param string[] $digest
      * @param null|string $entityBody
      * @throws Exception\InvalidArgumentException
      * @return string|bool
@@ -821,7 +841,7 @@ protected function calcAuthDigest($user, $password, $type = self::AUTH_BASIC, $d
                     throw new Exception\InvalidArgumentException('The digest cannot be empty');
                 }
                 foreach ($digest as $key => $value) {
-                    if (! defined('self::DIGEST_' . strtoupper($key))) {
+                    if (! defined('self::DIGEST_' . strtoupper((string) $key))) {
                         throw new Exception\InvalidArgumentException(sprintf(
                             'Invalid or not supported digest authentication parameter: \'%s\'',
                             $key
@@ -838,6 +858,8 @@ protected function calcAuthDigest($user, $password, $type = self::AUTH_BASIC, $d
                         );
                     }
                     $ha2 = md5($this->getMethod() . ':' . $this->getUri()->getPath() . ':' . md5($entityBody));
+                } else {
+                    throw new InvalidArgumentException('Invalid DIGEST auth data');
                 }
                 if (empty($digest['qop'])) {
                     $response = md5($ha1 . ':' . $digest['nonce'] . ':' . $ha2);
@@ -855,10 +877,15 @@ protected function calcAuthDigest($user, $password, $type = self::AUTH_BASIC, $d
      *
      * @param Stdlib\RequestInterface $request
      * @param Stdlib\ResponseInterface $response
+     * @throws UnexpectedValueException on $request not an instance of Zend\http\Request
      * @return Stdlib\ResponseInterface
      */
     public function dispatch(Stdlib\RequestInterface $request, Stdlib\ResponseInterface $response = null)
     {
+        if (! $request instanceof Request) {
+            throw UnexpectedValueException::unexpectedType(Request::class, $request);
+        }
+
         return $this->send($request);
     }
 
@@ -893,7 +920,7 @@ public function send(Request $request = null)
 
                 if (! empty($queryArray)) {
                     $newUri = $uri->toString();
-                    $queryString = http_build_query($queryArray, null, $this->getArgSeparator());
+                    $queryString = http_build_query($queryArray, '', $this->getArgSeparator());
 
                     if ($this->config['rfc3986strict']) {
                         $queryString = str_replace('+', '%20', $queryString);
@@ -925,7 +952,11 @@ public function send(Request $request = null)
             // headers
             $headers = $this->prepareHeaders($body, $uri);
 
-            $secure = $uri->getScheme() == 'https';
+            $secure = $uri->getScheme() === 'https';
+
+            if (null === $uri->getHost()) {
+                throw new InvalidArgumentException('Invalid URI in request');
+            }
 
             // cookies
             $cookie = $this->prepareCookies($uri->getHost(), $uri->getPath(), $secure);
@@ -933,15 +964,11 @@ public function send(Request $request = null)
                 $headers['Cookie'] = $cookie->getFieldValue();
             }
 
-            // check that adapter supports streaming before using it
-            if (is_resource($body) && ! ($adapter instanceof Client\Adapter\StreamInterface)) {
-                throw new Client\Exception\RuntimeException('Adapter does not support streaming');
-            }
-
             $this->streamHandle = null;
             // calling protected method to allow extending classes
             // to wrap the interaction with the adapter
             $response = $this->doRequest($uri, $method, $secure, $headers, $body);
+            /** @var null|resource $stream */
             $stream = $this->streamHandle;
             $this->streamHandle = null;
 
@@ -959,19 +986,36 @@ public function send(Request $request = null)
             }
 
             if ($this->config['outputstream']) {
+                if (! $adapter instanceof StreamInterface) {
+                    throw new Client\Exception\RuntimeException('Adapter does not support streaming');
+                }
+
                 if ($stream === null) {
+                    // @todo: check if it's really used
                     $stream = $this->getStream();
                     if (! is_resource($stream) && is_string($stream)) {
-                        $stream = fopen($stream, 'r');
+                        $stream = fopen($stream, 'rb');
                     }
                 }
+
+                if (! is_resource($stream)) {
+                    throw new UnexpectedValueException('Stream is not a resource');
+                }
+
                 $streamMetaData = stream_get_meta_data($stream);
                 if ($streamMetaData['seekable']) {
                     rewind($stream);
                 }
+
                 // cleanup the adapter
                 $adapter->setOutputStream(null);
                 $response = Response\Stream::fromStream($response, $stream);
+
+                // streamName can just be a string at this point
+                if (! is_string($this->streamName)) {
+                    throw new UnexpectedValueException('Unexpected value for streamName');
+                }
+
                 $response->setStreamName($this->streamName);
                 if (! is_string($this->config['outputstream'])) {
                     // we used temp name, will need to clean up
@@ -983,15 +1027,20 @@ public function send(Request $request = null)
 
             // Get the cookies from response (if any)
             $setCookies = $response->getCookie();
-            if (! empty($setCookies)) {
+            if (! is_bool($setCookies) && ! empty($setCookies)) {
                 $this->addCookie($setCookies);
             }
 
+            /** @var Headers $responseHeaders */
+            $responseHeaders = $response->getHeaders();
+
             // If we got redirected, look for the Location header
-            if ($response->isRedirect() && ($response->getHeaders()->has('Location'))) {
+            if ($response->isRedirect() && ($responseHeaders->has('Location'))) {
                 // Avoid problems with buggy servers that add whitespace at the
                 // end of some headers
-                $location = trim($response->getHeaders()->get('Location')->getFieldValue());
+                /** @var HeaderInterface $locationHeader */
+                $locationHeader = $responseHeaders->get('Location');
+                $location = trim($locationHeader->getFieldValue());
 
                 // Check whether we send the exact same request again, or drop the parameters
                 // and send a GET request
@@ -1024,8 +1073,9 @@ public function send(Request $request = null)
                         // Else, assume we have a relative path
                     } else {
                         // Get the current path directory, removing any trailing slashes
-                        $path = $this->getUri()->getPath();
-                        $path = rtrim(substr($path, 0, strrpos($path, '/')), '/');
+                        $path = $this->getUri()->getPath() ?: '/';
+                        $slashPosition = strrpos($path, '/') ?: 0;
+                        $path = rtrim(substr($path, 0, $slashPosition) ?: '', '/');
                         $this->getUri()->setPath($path . '/' . $location);
                     }
                 }
@@ -1120,10 +1170,10 @@ public function removeFileUpload($filename)
     /**
      * Prepare Cookies
      *
-     * @param   string $domain
-     * @param   string $path
+     * @param   null|string $domain
+     * @param   null|string $path
      * @param   bool $secure
-     * @return  Header\Cookie|bool
+     * @return  Header\Cookie
      */
     protected function prepareCookies($domain, $path, $secure)
     {
@@ -1161,6 +1211,11 @@ protected function prepareHeaders($body, $uri)
     {
         $headers = [];
 
+        $adapter = $this->getAdapter();
+
+        /** @var Headers|HeaderInterface[] $requestHeaders */
+        $requestHeaders = $this->getRequest()->getHeaders();
+
         // Set the host header
         if ($this->config['httpversion'] == Request::VERSION_11) {
             $host = $uri->getHost();
@@ -1175,7 +1230,7 @@ protected function prepareHeaders($body, $uri)
         }
 
         // Set the connection header
-        if (! $this->getRequest()->getHeaders()->has('Connection')) {
+        if (! $requestHeaders->has('Connection')) {
             if (! $this->config['keepalive']) {
                 $headers['Connection'] = 'close';
             }
@@ -1183,7 +1238,7 @@ protected function prepareHeaders($body, $uri)
 
         // Set the Accept-encoding header if not set - depending on whether
         // zlib is available or not.
-        if (! $this->getRequest()->getHeaders()->has('Accept-Encoding')) {
+        if (! $requestHeaders->has('Accept-Encoding')) {
             if (empty($this->config['outputstream']) && function_exists('gzinflate')) {
                 $headers['Accept-Encoding'] = 'gzip, deflate';
             } else {
@@ -1192,7 +1247,7 @@ protected function prepareHeaders($body, $uri)
         }
 
         // Set the user agent header
-        if (! $this->getRequest()->getHeaders()->has('User-Agent') && isset($this->config['useragent'])) {
+        if (! $requestHeaders->has('User-Agent') && isset($this->config['useragent'])) {
             $headers['User-Agent'] = $this->config['useragent'];
         }
 
@@ -1206,15 +1261,15 @@ protected function prepareHeaders($body, $uri)
                     }
                     break;
                 case self::AUTH_DIGEST:
-                    if (! $this->adapter instanceof Client\Adapter\Curl) {
+                    if (! $adapter instanceof Client\Adapter\Curl) {
                         throw new Exception\RuntimeException(sprintf(
                             'The digest authentication is only available for curl adapters (%s)',
                             Curl::class
                         ));
                     }
 
-                    $this->adapter->setCurlOption(CURLOPT_HTTPAUTH, CURLAUTH_DIGEST);
-                    $this->adapter->setCurlOption(CURLOPT_USERPWD, $this->auth['user'] . ':' . $this->auth['password']);
+                    $adapter->setCurlOption(CURLOPT_HTTPAUTH, CURLAUTH_DIGEST);
+                    $adapter->setCurlOption(CURLOPT_USERPWD, $this->auth['user'] . ':' . $this->auth['password']);
             }
         }
 
@@ -1235,7 +1290,6 @@ protected function prepareHeaders($body, $uri)
 
         // Merge the headers of the request (if any)
         // here we need right 'http field' and not lowercase letters
-        $requestHeaders = $this->getRequest()->getHeaders();
         foreach ($requestHeaders as $requestHeaderElement) {
             $headers[$requestHeaderElement->getFieldName()] = $requestHeaderElement->getFieldValue();
         }
@@ -1263,14 +1317,18 @@ protected function prepareBody()
         $body = '';
         $hasFiles = false;
 
-        if (! $this->getRequest()->getHeaders()->has('Content-Type')) {
+        /** @var Headers $headers */
+        $headers = $this->getRequest()->getHeaders();
+
+        if (! $headers->has('Content-Type')) {
             $hasFiles = ! empty($this->getRequest()->getFiles()->toArray());
             // If we have files to upload, force encType to multipart/form-data
             if ($hasFiles) {
                 $this->setEncType(self::ENC_FORMDATA);
             }
         } else {
-            $this->setEncType($this->getHeader('Content-Type'));
+            $contentType = $this->getHeader('Content-Type');
+            $this->setEncType(is_string($contentType) ? $contentType : '');
         }
 
         // If we have POST parameters or files, encode and add them to the body
@@ -1299,7 +1357,7 @@ protected function prepareBody()
                 $body .= '--' . $boundary . '--' . "\r\n";
             } elseif (stripos($this->getEncType(), self::ENC_URLENCODED) === 0) {
                 // Encode body as application/x-www-form-urlencoded
-                $body = http_build_query($this->getRequest()->getPost()->toArray(), null, '&');
+                $body = http_build_query($this->getRequest()->getPost()->toArray(), '', '&');
             } else {
                 throw new Client\Exception\RuntimeException(sprintf(
                     'Cannot handle content type \'%s\' automatically',
@@ -1332,14 +1390,16 @@ protected function detectFileMimeType($file)
 
         // First try with fileinfo functions
         if (function_exists('finfo_open')) {
+            $fileInfoDb = static::$fileInfoDb;
             if (static::$fileInfoDb === null) {
                 ErrorHandler::start();
-                static::$fileInfoDb = finfo_open(FILEINFO_MIME);
+                $fileInfoDb = finfo_open(FILEINFO_MIME);
                 ErrorHandler::stop();
             }
 
-            if (static::$fileInfoDb) {
-                $type = finfo_file(static::$fileInfoDb, $file);
+            if ($fileInfoDb) {
+                static::$fileInfoDb = $fileInfoDb;
+                $type = finfo_file($fileInfoDb, $file);
             }
         } elseif (function_exists('mime_content_type')) {
             $type = mime_content_type($file);
@@ -1413,7 +1473,7 @@ protected function flattenParametersArray($parray, $prefix = null)
                     $key = $prefix . sprintf('[%s]', $name);
                 }
             } else {
-                $key = $name;
+                $key = (string) $name;
             }
 
             if (is_array($value)) {
@@ -1440,19 +1500,25 @@ protected function flattenParametersArray($parray, $prefix = null)
      */
     protected function doRequest(Http $uri, $method, $secure = false, $headers = [], $body = '')
     {
+        if (null === $uri->getHost()) {
+            throw new InvalidArgumentException('URI does not have an host');
+        }
+
+        $adapter = $this->getAdapter();
+
         // Open the connection, send the request and read the response
-        $this->adapter->connect($uri->getHost(), $uri->getPort(), $secure);
+        $adapter->connect($uri->getHost(), $uri->getPort(), $secure);
 
         if ($this->config['outputstream']) {
-            if ($this->adapter instanceof Client\Adapter\StreamInterface) {
+            if ($adapter instanceof Client\Adapter\StreamInterface) {
                 $this->streamHandle = $this->openTempStream();
-                $this->adapter->setOutputStream($this->streamHandle);
+                $adapter->setOutputStream($this->streamHandle);
             } else {
                 throw new Exception\RuntimeException('Adapter does not support streaming');
             }
         }
         // HTTP connection
-        $this->lastRawRequest = $this->adapter->write(
+        $this->lastRawRequest = $adapter->write(
             $method,
             $uri,
             $this->config['httpversion'],
@@ -1460,7 +1526,7 @@ protected function doRequest(Http $uri, $method, $secure = false, $headers = [],
             $body
         );
 
-        return $this->adapter->read();
+        return $adapter->read();
     }
 
     /**
diff --git a/src/Client/Adapter/Curl.php b/src/Client/Adapter/Curl.php
index ff0e7cae1b..7d331cfa4f 100644
--- a/src/Client/Adapter/Curl.php
+++ b/src/Client/Adapter/Curl.php
@@ -56,14 +56,14 @@ class Curl implements HttpAdapter, StreamInterface
     /**
      * Response gotten from server
      *
-     * @var string
+     * @var null|string
      */
     protected $response;
 
     /**
      * Stream for storing output
      *
-     * @var resource
+     * @var null|resource
      */
     protected $outputStream;
 
@@ -133,7 +133,7 @@ public function setOptions($options = [])
         }
 
         foreach ($options as $k => $v) {
-            $option = strtolower($k);
+            $option = strtolower((string) $k);
             switch ($option) {
                 case 'proxyhost':
                     $this->setCurlOption(CURLOPT_PROXY, $v);
@@ -196,9 +196,10 @@ public function connect($host, $port = 80, $secure = false)
         }
 
         // Do the actual connection
-        $this->curl = curl_init();
+        $curl = curl_init();
+
         if ($port != 80) {
-            curl_setopt($this->curl, CURLOPT_PORT, intval($port));
+            curl_setopt($curl, CURLOPT_PORT, (int) $port);
         }
 
         if (isset($this->config['connecttimeout'])) {
@@ -222,33 +223,33 @@ public function connect($host, $port = 80, $secure = false)
 
         if ($connectTimeout !== null) {
             if (defined('CURLOPT_CONNECTTIMEOUT_MS')) {
-                curl_setopt($this->curl, CURLOPT_CONNECTTIMEOUT_MS, $connectTimeout * 1000);
+                curl_setopt($curl, CURLOPT_CONNECTTIMEOUT_MS, $connectTimeout * 1000);
             } else {
-                curl_setopt($this->curl, CURLOPT_CONNECTTIMEOUT, $connectTimeout);
+                curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, $connectTimeout);
             }
         }
 
         if (isset($this->config['timeout'])) {
             if (defined('CURLOPT_TIMEOUT_MS')) {
-                curl_setopt($this->curl, CURLOPT_TIMEOUT_MS, $this->config['timeout'] * 1000);
+                curl_setopt($curl, CURLOPT_TIMEOUT_MS, $this->config['timeout'] * 1000);
             } else {
-                curl_setopt($this->curl, CURLOPT_TIMEOUT, $this->config['timeout']);
+                curl_setopt($curl, CURLOPT_TIMEOUT, $this->config['timeout']);
             }
         }
 
         if (isset($this->config['sslcafile']) && $this->config['sslcafile']) {
-            curl_setopt($this->curl, CURLOPT_CAINFO, $this->config['sslcafile']);
+            curl_setopt($curl, CURLOPT_CAINFO, $this->config['sslcafile']);
         }
         if (isset($this->config['sslcapath']) && $this->config['sslcapath']) {
-            curl_setopt($this->curl, CURLOPT_CAPATH, $this->config['sslcapath']);
+            curl_setopt($curl, CURLOPT_CAPATH, $this->config['sslcapath']);
         }
 
         if (isset($this->config['maxredirects'])) {
             // Set Max redirects
-            curl_setopt($this->curl, CURLOPT_MAXREDIRS, $this->config['maxredirects']);
+            curl_setopt($curl, CURLOPT_MAXREDIRS, $this->config['maxredirects']);
         }
 
-        if (! $this->curl) {
+        if (! $curl) {
             $this->close();
 
             throw new AdapterException\RuntimeException('Unable to Connect to ' . $host . ':' . $port);
@@ -257,13 +258,15 @@ public function connect($host, $port = 80, $secure = false)
         if ($secure !== false) {
             // Behave the same like Zend\Http\Adapter\Socket on SSL options.
             if (isset($this->config['sslcert'])) {
-                curl_setopt($this->curl, CURLOPT_SSLCERT, $this->config['sslcert']);
+                curl_setopt($curl, CURLOPT_SSLCERT, $this->config['sslcert']);
             }
             if (isset($this->config['sslpassphrase'])) {
-                curl_setopt($this->curl, CURLOPT_SSLCERTPASSWD, $this->config['sslpassphrase']);
+                curl_setopt($curl, CURLOPT_SSLCERTPASSWD, $this->config['sslpassphrase']);
             }
         }
 
+        $this->curl = $curl;
+
         // Update connected_to
         $this->connectedTo = [$host, $port];
     }
@@ -271,20 +274,22 @@ public function connect($host, $port = 80, $secure = false)
     /**
      * Send request to the remote server
      *
-     * @param  string        $method
-     * @param  \Zend\Uri\Uri $uri
-     * @param  float         $httpVersion
-     * @param  array         $headers
-     * @param  string        $body
-     * @return string        $request
+     * @param  string          $method
+     * @param  \Zend\Uri\Uri   $uri
+     * @param  string           $httpVersion
+     * @param  array           $headers
+     * @param  string|resource $body
+     * @return string          $request
      * @throws AdapterException\RuntimeException If connection fails, connected
      *     to wrong host, no PUT file defined, unsupported method, or unsupported
      *     cURL option.
      * @throws AdapterException\InvalidArgumentException if $method is currently not supported
      * @throws AdapterException\TimeoutException if connection timed out
      */
-    public function write($method, $uri, $httpVersion = 1.1, $headers = [], $body = '')
+    public function write($method, $uri, $httpVersion = '1.1', $headers = [], $body = '')
     {
+        $httpVersion = (string) $httpVersion;
+
         // Make sure we're properly connected
         if (! $this->curl) {
             throw new AdapterException\RuntimeException('Trying to write but we are not connected');
@@ -380,7 +385,7 @@ public function write($method, $uri, $httpVersion = 1.1, $headers = [], $body =
         }
 
         // get http version to use
-        $curlHttp = $httpVersion == 1.1 ? CURL_HTTP_VERSION_1_1 : CURL_HTTP_VERSION_1_0;
+        $curlHttp = $httpVersion === '1.1' ? CURL_HTTP_VERSION_1_1 : CURL_HTTP_VERSION_1_0;
 
         // mark as HTTP request and set HTTP method
         curl_setopt($this->curl, CURLOPT_HTTP_VERSION, $curlHttp);
@@ -455,16 +460,11 @@ public function write($method, $uri, $httpVersion = 1.1, $headers = [], $body =
 
         // send the request
 
+        /** @var false|string $response */
         $response = curl_exec($this->curl);
-        // if we used streaming, headers are already there
-        if (! is_resource($this->outputStream)) {
-            $this->response = $response;
-        }
-
-        $request  = curl_getinfo($this->curl, CURLINFO_HEADER_OUT);
-        $request .= $body;
 
         if ($response === false || empty($this->response)) {
+            $this->response = null;
             if (curl_errno($this->curl) === static::ERROR_OPERATION_TIMEDOUT) {
                 throw new AdapterException\TimeoutException(
                     'Read timed out',
@@ -477,18 +477,28 @@ public function write($method, $uri, $httpVersion = 1.1, $headers = [], $body =
             ));
         }
 
+        // if we used streaming, headers are already there
+        if (! is_resource($this->outputStream)) {
+            $this->response = $response;
+        }
+
+        $request  = curl_getinfo($this->curl, CURLINFO_HEADER_OUT);
+        $request .= $body;
+
         // separating header from body because it is dangerous to accidentially replace strings in the body
         $responseHeaderSize = curl_getinfo($this->curl, CURLINFO_HEADER_SIZE);
         $responseHeaders = substr($this->response, 0, $responseHeaderSize);
 
         // cURL automatically decodes chunked-messages, this means we have to
         // disallow the Zend\Http\Response to do it again.
+        /** @var string $responseHeaders */
         $responseHeaders = preg_replace("/Transfer-Encoding:\s*chunked\\r\\n/i", '', $responseHeaders);
 
         // cURL can automatically handle content encoding; prevent double-decoding from occurring
         if (isset($this->config['curloptions'][CURLOPT_ENCODING])
             && '' == $this->config['curloptions'][CURLOPT_ENCODING]
         ) {
+            /** @var string $responseHeaders */
             $responseHeaders = preg_replace("/Content-Encoding:\s*gzip\\r\\n/i", '', $responseHeaders);
         }
 
@@ -505,9 +515,10 @@ public function write($method, $uri, $httpVersion = 1.1, $headers = [], $body =
         // Eliminate multiple HTTP responses.
         do {
             $parts = preg_split('|(?:\r?\n){2}|m', $this->response, 2);
+
             $again = false;
 
-            if (isset($parts[1]) && preg_match("|^HTTP/1\.[01](.*?)\r\n|mi", $parts[1])) {
+            if (is_array($parts) && isset($parts[1]) && preg_match("|^HTTP/1\.[01](.*?)\r\n|mi", $parts[1])) {
                 $this->response = $parts[1];
                 $again          = true;
             }
@@ -519,7 +530,7 @@ public function write($method, $uri, $httpVersion = 1.1, $headers = [], $body =
     /**
      * Return read response from server
      *
-     * @return string
+     * @return null|string
      */
     public function read()
     {
@@ -542,7 +553,7 @@ public function close()
     /**
      * Get cUrl Handle
      *
-     * @return resource
+     * @return null|resource
      */
     public function getHandle()
     {
@@ -552,7 +563,7 @@ public function getHandle()
     /**
      * Set output stream for the response
      *
-     * @param resource $stream
+     * @param null|resource $stream
      * @return $this
      */
     public function setOutputStream($stream)
diff --git a/src/Client/Adapter/Exception/UnexpectedValueException.php b/src/Client/Adapter/Exception/UnexpectedValueException.php
new file mode 100644
index 0000000000..f4f3af3693
--- /dev/null
+++ b/src/Client/Adapter/Exception/UnexpectedValueException.php
@@ -0,0 +1,15 @@
+<?php
+/**
+ * @see       https://github.com/zendframework/zend-http for the canonical source repository
+ * @copyright Copyright (c) 2005-2017 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-http/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Http\Client\Adapter\Exception;
+
+use Zend\Http\Client\Exception;
+
+class UnexpectedValueException extends Exception\UnexpectedValueException implements
+    ExceptionInterface
+{
+}
diff --git a/src/Client/Adapter/Proxy.php b/src/Client/Adapter/Proxy.php
index e401c5bef6..b9e1e68a3b 100644
--- a/src/Client/Adapter/Proxy.php
+++ b/src/Client/Adapter/Proxy.php
@@ -118,11 +118,11 @@ public function connect($host, $port = 80, $secure = false)
     /**
      * Send request to the proxy server
      *
-     * @param string        $method
-     * @param \Zend\Uri\Uri $uri
-     * @param string        $httpVer
-     * @param array         $headers
-     * @param string        $body
+     * @param string          $method
+     * @param \Zend\Uri\Uri   $uri
+     * @param string          $httpVer
+     * @param array           $headers
+     * @param string|resource $body
      * @throws AdapterException\RuntimeException
      * @return string Request as string
      */
@@ -159,9 +159,19 @@ public function write($method, $uri, $httpVer = '1.1', $headers = [], $body = ''
             );
         }
 
+        $host   = $uri->getHost();
+        $scheme = $uri->getScheme();
+        $port   = $uri->getPort();
+
+        if (null === $host || null === $scheme || null === $port) {
+            throw new AdapterException\InvalidArgumentException(
+                'Invalid Uri object'
+            );
+        }
+
         // if we are proxying HTTPS, preform CONNECT handshake with the proxy
         if ($isSecure && ! $this->negotiated) {
-            $this->connectHandshake($uri->getHost(), $uri->getPort(), $httpVer, $headers);
+            $this->connectHandshake($host, $port, $httpVer, $headers);
             $this->negotiated = true;
         }
 
@@ -226,6 +236,10 @@ public function write($method, $uri, $httpVer = '1.1', $headers = [], $body = ''
      */
     protected function connectHandshake($host, $port = 443, $httpVer = '1.1', array &$headers = [])
     {
+        if (null === $this->socket) {
+            throw new AdapterException\RuntimeException('Socket is not initialized');
+        }
+
         $request = 'CONNECT ' . $host . ':' . $port . ' HTTP/' . $httpVer . "\r\n"
             . 'Host: ' . $host . "\r\n";
 
diff --git a/src/Client/Adapter/Socket.php b/src/Client/Adapter/Socket.php
index a443f40fdc..7cc35cf97f 100644
--- a/src/Client/Adapter/Socket.php
+++ b/src/Client/Adapter/Socket.php
@@ -10,6 +10,8 @@
 use Traversable;
 use Zend\Http\Client\Adapter\AdapterInterface as HttpAdapter;
 use Zend\Http\Client\Adapter\Exception as AdapterException;
+use Zend\Http\Header\HeaderInterface;
+use Zend\Http\Headers;
 use Zend\Http\Request;
 use Zend\Http\Response;
 use Zend\Stdlib\ArrayUtils;
@@ -50,7 +52,7 @@ class Socket implements HttpAdapter, StreamInterface
     /**
      * Stream for storing output
      *
-     * @var resource
+     * @var null|resource
      */
     protected $outStream;
 
@@ -82,7 +84,7 @@ class Socket implements HttpAdapter, StreamInterface
     /**
      * Stream context
      *
-     * @var resource
+     * @var null|resource
      */
     protected $context;
 
@@ -283,10 +285,10 @@ public function connect($host, $port = 80, $secure = false)
                 (int) $connectTimeout,
                 $flags,
                 $context
-            );
+            ) ?: null;
             $error = ErrorHandler::stop();
 
-            if (! $this->socket) {
+            if (! is_resource($this->socket)) {
                 $this->close();
                 throw new AdapterException\RuntimeException(
                     sprintf(
@@ -368,11 +370,11 @@ public function connect($host, $port = 80, $secure = false)
     /**
      * Send request to the remote server
      *
-     * @param string        $method
-     * @param \Zend\Uri\Uri $uri
-     * @param string        $httpVer
-     * @param array         $headers
-     * @param string        $body
+     * @param string          $method
+     * @param \Zend\Uri\Uri   $uri
+     * @param string          $httpVer
+     * @param array           $headers
+     * @param string|resource $body
      * @throws AdapterException\RuntimeException
      * @return string Request as string
      */
@@ -384,8 +386,17 @@ public function write($method, $uri, $httpVer = '1.1', $headers = [], $body = ''
         }
 
         $host = $uri->getHost();
-        $host = (strtolower($uri->getScheme()) == 'https' ? $this->config['ssltransport'] : 'tcp') . '://' . $host;
-        if ($this->connectedTo[0] != $host || $this->connectedTo[1] != $uri->getPort()) {
+        $scheme = $uri->getScheme();
+        $port = $uri->getPort();
+
+        if (null === $host || null === $scheme || null === $port) {
+            throw new AdapterException\InvalidArgumentException(
+                'Invalid Uri object'
+            );
+        }
+
+        $host = (strtolower($scheme) == 'https' ? $this->config['ssltransport'] : 'tcp') . '://' . $host;
+        if ($this->connectedTo[0] != $host || $this->connectedTo[1] != $port) {
             throw new AdapterException\RuntimeException('Trying to write but we are connected to the wrong host');
         }
 
@@ -440,7 +451,12 @@ public function read()
         $response = '';
         $gotStatus = false;
 
-        while (($line = fgets($this->socket)) !== false) {
+        if (null === $this->socket) {
+            throw new AdapterException\RuntimeException('Socket is not initialized');
+        }
+
+        $line = fgets($this->socket);
+        while (false !== $line) {
             $gotStatus = $gotStatus || (strpos($line, 'HTTP') !== false);
             if ($gotStatus) {
                 $response .= $line;
@@ -448,6 +464,8 @@ public function read()
                     break;
                 }
             }
+
+            $line = fgets($this->socket);
         }
 
         $this->_checkSocketReadTimeout();
@@ -462,6 +480,7 @@ public function read()
         }
 
         // Check headers to see what kind of connection / transfer encoding we have
+        /** @var Headers $headers */
         $headers = $responseObj->getHeaders();
 
         /**
@@ -473,6 +492,7 @@ public function read()
             || $this->method == Request::METHOD_HEAD
         ) {
             // Close the connection if requested to do so by the server
+            /** @var false|HeaderInterface $connection */
             $connection = $headers->get('connection');
             if ($connection && $connection->getFieldValue() == 'close') {
                 $this->close();
@@ -481,7 +501,9 @@ public function read()
         }
 
         // If we got a 'transfer-encoding: chunked' header
+        /** @var false|HeaderInterface $transferEncoding */
         $transferEncoding = $headers->get('transfer-encoding');
+        /** @var false|HeaderInterface $contentLength */
         $contentLength = $headers->get('content-length');
         if ($transferEncoding !== false) {
             if (strtolower($transferEncoding->getFieldValue()) == 'chunked') {
@@ -489,6 +511,10 @@ public function read()
                     $line  = fgets($this->socket);
                     $this->_checkSocketReadTimeout();
 
+                    if (false === $line) {
+                        throw new AdapterException\RuntimeException('Unable to read from socket resource');
+                    }
+
                     $chunk = $line;
 
                     // Figure out the next chunk size
@@ -502,7 +528,7 @@ public function read()
                     }
 
                     // Convert the hexadecimal value to plain integer
-                    $chunksize = hexdec($chunksize);
+                    $chunksize = (int) hexdec($chunksize);
 
                     // Read next chunk
                     $readTo = ftell($this->socket) + $chunksize;
@@ -557,7 +583,7 @@ public function read()
             if (is_array($contentLength)) {
                 $contentLength = $contentLength[count($contentLength) - 1];
             }
-            $contentLength = $contentLength->getFieldValue();
+            $contentLength = (int) $contentLength->getFieldValue();
 
             $currentPos = ftell($this->socket);
 
@@ -608,8 +634,9 @@ public function read()
         }
 
         // Close the connection if requested to do so by the server
+        /** @var false|HeaderInterface $connection */
         $connection = $headers->get('connection');
-        if ($connection && $connection->getFieldValue() == 'close') {
+        if ($connection && $connection->getFieldValue() === 'close') {
             $this->close();
         }
 
@@ -641,23 +668,29 @@ public function close()
     protected function _checkSocketReadTimeout()
     {
         // @codingStandardsIgnoreEnd
-        if ($this->socket) {
-            $info = stream_get_meta_data($this->socket);
-            $timedout = $info['timed_out'];
-            if ($timedout) {
-                $this->close();
-                throw new AdapterException\TimeoutException(
-                    sprintf('Read timed out after %d seconds', $this->config['timeout']),
-                    AdapterException\TimeoutException::READ_TIMEOUT
-                );
-            }
+        if (! $this->socket) {
+            return;
         }
+
+        $info = stream_get_meta_data($this->socket);
+        $timedout = $info['timed_out'];
+
+        if (! $timedout) {
+            return;
+        }
+
+        $this->close();
+
+        throw new AdapterException\TimeoutException(
+            sprintf('Read timed out after %d seconds', $this->config['timeout']),
+            AdapterException\TimeoutException::READ_TIMEOUT
+        );
     }
 
     /**
      * Set output stream for the response
      *
-     * @param resource $stream
+     * @param null|resource $stream
      * @return \Zend\Http\Client\Adapter\Socket
      */
     public function setOutputStream($stream)
diff --git a/src/Client/Adapter/StreamInterface.php b/src/Client/Adapter/StreamInterface.php
index 808f324e19..8868d25f8d 100644
--- a/src/Client/Adapter/StreamInterface.php
+++ b/src/Client/Adapter/StreamInterface.php
@@ -19,7 +19,7 @@ interface StreamInterface
      *
      * This function sets output stream where the result will be stored.
      *
-     * @param resource $stream Stream to write the output to
+     * @param null|resource $stream Stream to write the output to
      *
      */
     public function setOutputStream($stream);
diff --git a/src/Client/Adapter/Test.php b/src/Client/Adapter/Test.php
index d65bba191e..ff5298e2d0 100644
--- a/src/Client/Adapter/Test.php
+++ b/src/Client/Adapter/Test.php
@@ -61,7 +61,7 @@ public function __construct()
      * Set the nextRequestWillFail flag
      *
      * @param  bool $flag
-     * @return \Zend\Http\Client\Adapter\Test
+     * @return self
      */
     public function setNextRequestWillFail($flag)
     {
diff --git a/src/Client/Exception/UnexpectedValueException.php b/src/Client/Exception/UnexpectedValueException.php
new file mode 100644
index 0000000000..7e5472c7be
--- /dev/null
+++ b/src/Client/Exception/UnexpectedValueException.php
@@ -0,0 +1,15 @@
+<?php
+/**
+ * @see       https://github.com/zendframework/zend-http for the canonical source repository
+ * @copyright Copyright (c) 2005-2017 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-http/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Http\Client\Exception;
+
+use Zend\Http\Exception;
+
+class UnexpectedValueException extends Exception\UnexpectedValueException implements
+    ExceptionInterface
+{
+}
diff --git a/src/ClientStatic.php b/src/ClientStatic.php
index 4228f68b3e..02b73ec98f 100644
--- a/src/ClientStatic.php
+++ b/src/ClientStatic.php
@@ -7,6 +7,8 @@
 
 namespace Zend\Http;
 
+use Traversable;
+
 /**
  * Http static client
  */
@@ -20,7 +22,7 @@ class ClientStatic
     /**
      * Get the static HTTP client
      *
-     * @param array|Traversable $options
+     * @param array|Traversable|null $options
      * @return Client
      */
     protected static function getStaticClient($options = null)
@@ -56,7 +58,9 @@ public static function get($url, $query = [], $headers = [], $body = null, $clie
         }
 
         if (! empty($headers) && is_array($headers)) {
-            $request->getHeaders()->addHeaders($headers);
+            /** @var Headers $requestHeaders */
+            $requestHeaders = $request->getHeaders();
+            $requestHeaders->addHeaders($headers);
         }
 
         if (! empty($body)) {
@@ -98,7 +102,9 @@ public static function post($url, $params, $headers = [], $body = null, $clientO
         }
 
         if (! empty($headers) && is_array($headers)) {
-            $request->getHeaders()->addHeaders($headers);
+            /** @var Headers $requestHeaders */
+            $requestHeaders = $request->getHeaders();
+            $requestHeaders->addHeaders($headers);
         }
 
         if (! empty($body)) {
diff --git a/src/Cookies.php b/src/Cookies.php
index 0f44b8ef18..dad5ecc56b 100644
--- a/src/Cookies.php
+++ b/src/Cookies.php
@@ -8,6 +8,8 @@
 namespace Zend\Http;
 
 use ArrayIterator;
+use Zend\Http\Exception\InvalidArgumentException;
+use Zend\Http\Exception\LogicException;
 use Zend\Http\Header\SetCookie;
 use Zend\Uri;
 
@@ -71,7 +73,7 @@ class Cookies extends Headers
     /**
      * @static
      * @throws Exception\RuntimeException
-     * @param $string
+     * @param string $string
      * @return void
      */
     public static function fromString($string)
@@ -87,13 +89,13 @@ public static function fromString($string)
      * or as a string - in which case an object is created from the string.
      *
      * @param SetCookie|string $cookie
-     * @param Uri\Uri|string $refUri Optional reference URI (for domain, path, secure)
+     * @param null|Uri\Uri|string $refUri Optional reference URI (for domain, path, secure)
      * @throws Exception\InvalidArgumentException
      */
     public function addCookie($cookie, $refUri = null)
     {
         if (is_string($cookie)) {
-            $cookie = SetCookie::fromString($cookie, $refUri);
+            $cookie = SetCookie::fromString($cookie);
         }
 
         if ($cookie instanceof SetCookie) {
@@ -120,14 +122,16 @@ public function addCookie($cookie, $refUri = null)
      */
     public function addCookiesFromResponse(Response $response, $refUri)
     {
-        $cookieHdrs = $response->getHeaders()->get('Set-Cookie');
+        /** @var Headers $headers */
+        $headers = $response->getHeaders();
+        $cookieHeaders = $headers->get('Set-Cookie');
 
-        if (is_array($cookieHdrs) || $cookieHdrs instanceof ArrayIterator) {
-            foreach ($cookieHdrs as $cookie) {
+        if ($cookieHeaders instanceof ArrayIterator) {
+            foreach ($cookieHeaders as $cookie) {
                 $this->addCookie($cookie, $refUri);
             }
-        } elseif (is_string($cookieHdrs)) {
-            $this->addCookie($cookieHdrs, $refUri);
+        } elseif (is_string($cookieHeaders)) {
+            $this->addCookie($cookieHeaders, $refUri);
         }
     }
 
@@ -197,7 +201,7 @@ public function getMatchingCookies(
      * @param string $cookieName The cookie's name
      * @param int $retAs Whether to return cookies as objects of \Zend\Http\Header\SetCookie or as strings
      * @throws Exception\InvalidArgumentException if invalid URI specified or invalid $retAs value
-     * @return SetCookie|string
+     * @return SetCookie|string|bool
      */
     public function getCookie($uri, $cookieName, $retAs = self::COOKIE_OBJECT)
     {
@@ -213,7 +217,7 @@ public function getCookie($uri, $cookieName, $retAs = self::COOKIE_OBJECT)
         }
 
         // Get correct cookie path
-        $path = $uri->getPath();
+        $path = $uri->getPath() ?: '/';
         $lastSlashPos = strrpos($path, '/') ?: 0;
         $path = substr($path, 0, $lastSlashPos);
         if (! $path) {
@@ -221,6 +225,7 @@ public function getCookie($uri, $cookieName, $retAs = self::COOKIE_OBJECT)
         }
 
         if (isset($this->cookies[$uri->getHost()][$path][$cookieName])) {
+            /** @var SetCookie $cookie */
             $cookie = $this->cookies[$uri->getHost()][$path][$cookieName];
 
             switch ($retAs) {
@@ -229,7 +234,7 @@ public function getCookie($uri, $cookieName, $retAs = self::COOKIE_OBJECT)
 
                 case self::COOKIE_STRING_ARRAY:
                 case self::COOKIE_STRING_CONCAT:
-                    return $cookie->__toString();
+                    return $cookie->toString();
 
                 default:
                     throw new Exception\InvalidArgumentException(sprintf(
@@ -260,25 +265,30 @@ protected function _flattenCookiesArray($ptr, $retAs = self::COOKIE_OBJECT)
                 if ($retAs == self::COOKIE_STRING_CONCAT) {
                     $ret .= $this->_flattenCookiesArray($item, $retAs);
                 } else {
-                    $ret = array_merge($ret, $this->_flattenCookiesArray($item, $retAs));
+                    $flatten = $this->_flattenCookiesArray($item, $retAs);
+                    if (! is_array($ret) || ! is_array($flatten)) {
+                        throw new LogicException('Flatten cookies is not an array');
+                    }
+                    $ret = array_merge($ret, $flatten);
                 }
             }
             return $ret;
-        } elseif ($ptr instanceof SetCookie) {
+        }
+
+        if ($ptr instanceof SetCookie) {
             switch ($retAs) {
                 case self::COOKIE_STRING_ARRAY:
-                    return [$ptr->__toString()];
+                    return [$ptr->toString()];
 
                 case self::COOKIE_STRING_CONCAT:
-                    return $ptr->__toString();
+                case self::COOKIE_STRING_CONCAT_STRICT:
+                    return $ptr->toString();
 
                 case self::COOKIE_OBJECT:
                 default:
                     return [$ptr];
             }
         }
-
-        return;
     }
 
     /**
@@ -305,7 +315,7 @@ protected function _matchDomain($domain)
     /**
      * Return a subset of a domain-matching cookies that also match a specified path
      *
-     * @param array $domains
+     * @param array<string, array<string, mixed>> $domains
      * @param string $path
      * @return array
      */
@@ -316,7 +326,9 @@ protected function _matchPath($domains, $path)
         $ret = [];
 
         foreach ($domains as $dom => $pathsArray) {
-            foreach (array_keys($pathsArray) as $cpath) {
+            /** @var string[] $keys */
+            $keys = array_keys($pathsArray);
+            foreach ($keys as $cpath) {
                 if (SetCookie::matchCookiePath($cpath, $path)) {
                     if (! isset($ret[$dom])) {
                         $ret[$dom] = [];
diff --git a/src/Exception/LogicException.php b/src/Exception/LogicException.php
new file mode 100644
index 0000000000..48f9dbc4a0
--- /dev/null
+++ b/src/Exception/LogicException.php
@@ -0,0 +1,13 @@
+<?php
+/**
+ * @see       https://github.com/zendframework/zend-http for the canonical source repository
+ * @copyright Copyright (c) 2005-2017 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-http/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Http\Exception;
+
+class LogicException extends \LogicException implements
+    ExceptionInterface
+{
+}
diff --git a/src/Exception/UnexpectedValueException.php b/src/Exception/UnexpectedValueException.php
new file mode 100644
index 0000000000..293eb94862
--- /dev/null
+++ b/src/Exception/UnexpectedValueException.php
@@ -0,0 +1,26 @@
+<?php
+/**
+ * @see       https://github.com/zendframework/zend-http for the canonical source repository
+ * @copyright Copyright (c) 2005-2017 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-http/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Http\Exception;
+
+class UnexpectedValueException extends \UnexpectedValueException implements ExceptionInterface
+{
+    /**
+     * @param string $expected
+     * @param mixed $actual
+     *
+     * @return UnexpectedValueException
+     */
+    public static function unexpectedType($expected, $actual)
+    {
+        return new static(sprintf(
+            'Expected %s. %s given',
+            $expected,
+            is_object($actual) ? get_class($actual) : gettype($actual)
+        ));
+    }
+}
diff --git a/src/Header/AbstractAccept.php b/src/Header/AbstractAccept.php
index 8d7ecb672a..1288f8e711 100644
--- a/src/Header/AbstractAccept.php
+++ b/src/Header/AbstractAccept.php
@@ -7,8 +7,6 @@
 
 namespace Zend\Http\Header;
 
-use stdClass;
-
 /**
  * Abstract Accept Header
  *
@@ -37,7 +35,7 @@
 abstract class AbstractAccept implements HeaderInterface
 {
     /**
-     * @var stdClass[]
+     * @var object[]
      */
     protected $fieldValueParts = [];
 
@@ -117,7 +115,7 @@ public function getFieldValuePartsFromHeaderLine($headerLine)
      * Parse the accept params belonging to a media range
      *
      * @param string $fieldValuePart
-     * @return stdClass
+     * @return object
      */
     protected function parseFieldValuePart($fieldValuePart)
     {
@@ -156,7 +154,7 @@ protected function parseFieldValuePart($fieldValuePart)
     protected function getParametersFromFieldValuePart($fieldValuePart)
     {
         $params = [];
-        if ((($pos = strpos($fieldValuePart, ';')) !== false)) {
+        if (strpos($fieldValuePart, ';') !== false) {
             preg_match_all('/(?:[^;"]|"(?:[^\\\"]|\\\.)*")+/', $fieldValuePart, $paramsStrings);
 
             if (isset($paramsStrings[0])) {
@@ -167,12 +165,13 @@ protected function getParametersFromFieldValuePart($fieldValuePart)
             foreach ($paramsStrings as $param) {
                 $explode = explode('=', $param, 2);
 
-                if (count($explode) === 2) {
-                    $value = trim($explode[1]);
-                } else {
-                    $value = null;
+                if (count($explode) === 1) {
+                    $params[trim($explode[0])] = '';
+                    break;
                 }
 
+                $value = trim($explode[1]);
+
                 if (isset($value[0]) && $value[0] == '"' && substr($value, -1) == '"') {
                     $value = substr(substr($value, 1), 0, -1);
                 }
@@ -240,7 +239,7 @@ function ($v) {
      *
      * @param  string $type
      * @param  int|float $priority
-     * @param  array (optional) $params
+     * @param  array $params (optional)
      * @throws Exception\InvalidArgumentException
      * @return $this
      */
@@ -285,14 +284,14 @@ protected function addType($type, $priority = 1, array $params = [])
      */
     protected function hasType($matchAgainst)
     {
-        return (bool) $this->match($matchAgainst);
+        return false !== $this->match($matchAgainst);
     }
 
     /**
      * Match a media string against this header
      *
      * @param array|string $matchAgainst
-     * @return Accept\FieldValuePArt\AcceptFieldValuePart|bool The matched value or false
+     * @return Accept\FieldValuePart\AcceptFieldValuePart|bool The matched value or false
      */
     public function match($matchAgainst)
     {
@@ -330,9 +329,9 @@ public function match($matchAgainst)
     /**
      * Return a match where all parameters in argument #1 match those in argument #2
      *
-     * @param array $match1
-     * @param array $match2
-     * @return bool|array
+     * @param object $match1
+     * @param object $match2
+     * @return bool|object
      */
     protected function matchAcceptParams($match1, $match2)
     {
@@ -376,8 +375,8 @@ protected function matchAcceptParams($match1, $match2)
     /**
      * Add a key/value combination to the internal queue
      *
-     * @param stdClass $value
-     * @return number
+     * @param object $value
+     * @return void
      */
     protected function addFieldValuePartToQueue($value)
     {
diff --git a/src/Header/AbstractDate.php b/src/Header/AbstractDate.php
index 001a907cb8..d0d9cf23cc 100644
--- a/src/Header/AbstractDate.php
+++ b/src/Header/AbstractDate.php
@@ -95,7 +95,13 @@ public static function fromString($headerLine)
      */
     public static function fromTimeString($time)
     {
-        return static::fromTimestamp(strtotime($time));
+        $timestamp = strtotime((string) $time);
+
+        if (false === $timestamp) {
+            throw new Exception\InvalidArgumentException(sprintf('Invalid time %s', $time));
+        }
+
+        return static::fromTimestamp($timestamp);
     }
 
     /**
@@ -159,14 +165,16 @@ public function setDate($date)
     {
         if (is_string($date)) {
             try {
-                $date = new DateTime($date, new DateTimeZone('GMT'));
+                $dateObj = new DateTime($date, new DateTimeZone('GMT'));
             } catch (\Exception $e) {
                 throw new Exception\InvalidArgumentException(
-                    sprintf('Invalid date passed as string (%s)', (string) $date),
+                    sprintf('Invalid date passed as string (%s)', $date),
                     $e->getCode(),
                     $e
                 );
             }
+
+            $date = $dateObj;
         } elseif (! ($date instanceof DateTime)) {
             throw new Exception\InvalidArgumentException('Date must be an instance of \DateTime or a string');
         }
@@ -195,7 +203,7 @@ public function getDate()
     public function date()
     {
         if ($this->date === null) {
-            $this->date = new DateTime(null, new DateTimeZone('GMT'));
+            $this->date = new DateTime('now', new DateTimeZone('GMT'));
         }
         return $this->date;
     }
@@ -213,14 +221,16 @@ public function compareTo($date)
     {
         if (is_string($date)) {
             try {
-                $date = new DateTime($date, new DateTimeZone('GMT'));
+                $dateObj = new DateTime($date, new DateTimeZone('GMT'));
             } catch (\Exception $e) {
                 throw new Exception\InvalidArgumentException(
-                    sprintf('Invalid Date passed as string (%s)', (string) $date),
+                    sprintf('Invalid Date passed as string (%s)', $date),
                     $e->getCode(),
                     $e
                 );
             }
+
+            $date = $dateObj;
         } elseif (! ($date instanceof DateTime)) {
             throw new Exception\InvalidArgumentException('Date must be an instance of \DateTime or a string');
         }
diff --git a/src/Header/Accept.php b/src/Header/Accept.php
index 19d131dcaf..5c41231b0a 100644
--- a/src/Header/Accept.php
+++ b/src/Header/Accept.php
@@ -51,7 +51,9 @@ public function toString()
      */
     public function addMediaType($type, $priority = 1, array $params = [])
     {
-        return $this->addType($type, $priority, $params);
+        $this->addType($type, $priority, $params);
+
+        return $this;
     }
 
     /**
diff --git a/src/Header/Accept/FieldValuePart/AbstractFieldValuePart.php b/src/Header/Accept/FieldValuePart/AbstractFieldValuePart.php
index 95e2020cfc..bce07c447d 100644
--- a/src/Header/Accept/FieldValuePart/AbstractFieldValuePart.php
+++ b/src/Header/Accept/FieldValuePart/AbstractFieldValuePart.php
@@ -69,7 +69,7 @@ protected function getInternalValues()
      */
     public function getTypeString()
     {
-        return $this->getInternalValues()->typeString;
+        return $this->typeString;
     }
 
     /**
@@ -77,15 +77,15 @@ public function getTypeString()
      */
     public function getPriority()
     {
-        return (float) $this->getInternalValues()->priority;
+        return (float) $this->priority;
     }
 
     /**
-     * @return \stdClass $params
+     * @return object $params
      */
     public function getParams()
     {
-        return (object) $this->getInternalValues()->params;
+        return (object) $this->params;
     }
 
     /**
@@ -93,7 +93,7 @@ public function getParams()
      */
     public function getRaw()
     {
-        return $this->getInternalValues()->raw;
+        return $this->raw;
     }
 
     /**
diff --git a/src/Header/Accept/FieldValuePart/AcceptFieldValuePart.php b/src/Header/Accept/FieldValuePart/AcceptFieldValuePart.php
index 8631b64488..7955e8f442 100644
--- a/src/Header/Accept/FieldValuePart/AcceptFieldValuePart.php
+++ b/src/Header/Accept/FieldValuePart/AcceptFieldValuePart.php
@@ -19,7 +19,7 @@ class AcceptFieldValuePart extends AbstractFieldValuePart
      */
     public function getSubtype()
     {
-        return $this->getInternalValues()->subtype;
+        return $this->subtype;
     }
 
     /**
@@ -27,7 +27,7 @@ public function getSubtype()
      */
     public function getSubtypeRaw()
     {
-        return $this->getInternalValues()->subtypeRaw;
+        return $this->subtypeRaw;
     }
 
     /**
@@ -35,6 +35,6 @@ public function getSubtypeRaw()
      */
     public function getFormat()
     {
-        return $this->getInternalValues()->format;
+        return $this->format;
     }
 }
diff --git a/src/Header/Accept/FieldValuePart/CharsetFieldValuePart.php b/src/Header/Accept/FieldValuePart/CharsetFieldValuePart.php
index e137c493ac..11e6c5d59f 100644
--- a/src/Header/Accept/FieldValuePart/CharsetFieldValuePart.php
+++ b/src/Header/Accept/FieldValuePart/CharsetFieldValuePart.php
@@ -19,6 +19,6 @@ class CharsetFieldValuePart extends AbstractFieldValuePart
      */
     public function getCharset()
     {
-        return $this->getInternalValues()->type;
+        return $this->type;
     }
 }
diff --git a/src/Header/Accept/FieldValuePart/EncodingFieldValuePart.php b/src/Header/Accept/FieldValuePart/EncodingFieldValuePart.php
index de26751138..b5a2ac47ef 100644
--- a/src/Header/Accept/FieldValuePart/EncodingFieldValuePart.php
+++ b/src/Header/Accept/FieldValuePart/EncodingFieldValuePart.php
@@ -19,6 +19,6 @@ class EncodingFieldValuePart extends AbstractFieldValuePart
      */
     public function getEncoding()
     {
-        return $this->getInternalValues()->type;
+        return $this->type;
     }
 }
diff --git a/src/Header/Accept/FieldValuePart/LanguageFieldValuePart.php b/src/Header/Accept/FieldValuePart/LanguageFieldValuePart.php
index 0ca4c0a0c7..77affe6211 100644
--- a/src/Header/Accept/FieldValuePart/LanguageFieldValuePart.php
+++ b/src/Header/Accept/FieldValuePart/LanguageFieldValuePart.php
@@ -16,16 +16,16 @@ class LanguageFieldValuePart extends AbstractFieldValuePart
 {
     public function getLanguage()
     {
-        return $this->getInternalValues()->typeString;
+        return $this->typeString;
     }
 
     public function getPrimaryTag()
     {
-        return $this->getInternalValues()->type;
+        return $this->type;
     }
 
     public function getSubTag()
     {
-        return $this->getInternalValues()->subtype;
+        return $this->subtype;
     }
 }
diff --git a/src/Header/AcceptCharset.php b/src/Header/AcceptCharset.php
index 8d196ec7a4..5994c7ca2d 100644
--- a/src/Header/AcceptCharset.php
+++ b/src/Header/AcceptCharset.php
@@ -47,7 +47,9 @@ public function toString()
      */
     public function addCharset($type, $priority = 1)
     {
-        return $this->addType($type, $priority);
+        $this->addType($type, $priority);
+
+        return $this;
     }
 
     /**
diff --git a/src/Header/AcceptEncoding.php b/src/Header/AcceptEncoding.php
index da1c960e47..61b552a2a7 100644
--- a/src/Header/AcceptEncoding.php
+++ b/src/Header/AcceptEncoding.php
@@ -47,7 +47,9 @@ public function toString()
      */
     public function addEncoding($type, $priority = 1)
     {
-        return $this->addType($type, $priority);
+        $this->addType($type, $priority);
+
+        return $this;
     }
 
     /**
diff --git a/src/Header/AcceptLanguage.php b/src/Header/AcceptLanguage.php
index c8a90b2544..9452df557e 100644
--- a/src/Header/AcceptLanguage.php
+++ b/src/Header/AcceptLanguage.php
@@ -47,7 +47,9 @@ public function toString()
      */
     public function addLanguage($type, $priority = 1)
     {
-        return $this->addType($type, $priority);
+        $this->addType($type, $priority);
+
+        return $this;
     }
 
     /**
diff --git a/src/Header/CacheControl.php b/src/Header/CacheControl.php
index 1aab3c009f..daae61d586 100644
--- a/src/Header/CacheControl.php
+++ b/src/Header/CacheControl.php
@@ -186,14 +186,13 @@ protected static function parseValue($value)
         switch (static::match(['[a-zA-Z][a-zA-Z_-]*'], $value, $lastMatch)) {
             case 0:
                 $directive = $lastMatch;
-                goto state_value;
+                break;
                 // intentional fall-through
 
             default:
                 throw new Exception\InvalidArgumentException('expected DIRECTIVE');
         }
 
-        state_value:
         switch (static::match(['="[^"]*"', '=[^",\s;]*'], $value, $lastMatch)) {
             case 0:
                 $directives[$directive] = substr($lastMatch, 2, -1);
diff --git a/src/Header/ContentSecurityPolicy.php b/src/Header/ContentSecurityPolicy.php
index 21402634e2..3fd4304986 100644
--- a/src/Header/ContentSecurityPolicy.php
+++ b/src/Header/ContentSecurityPolicy.php
@@ -124,7 +124,7 @@ public function setDirective($name, array $sources)
             return $this;
         }
 
-        array_walk($sources, [__NAMESPACE__ . '\HeaderValue', 'assertValid']);
+        array_walk($sources, [HeaderValue::class, 'assertValid']);
         $this->directives[$name] = implode(' ', $sources);
 
         return $this;
diff --git a/src/Header/ContentType.php b/src/Header/ContentType.php
index 5de3572890..6c68326bb4 100644
--- a/src/Header/ContentType.php
+++ b/src/Header/ContentType.php
@@ -7,8 +7,6 @@
 
 namespace Zend\Http\Header;
 
-use stdClass;
-
 /**
  * @throws Exception\InvalidArgumentException
  * @see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.17
@@ -16,7 +14,7 @@
 class ContentType implements HeaderInterface
 {
     /**
-     * @var string
+     * @var null|string
      */
     protected $mediaType;
 
@@ -26,7 +24,7 @@ class ContentType implements HeaderInterface
     protected $parameters = [];
 
     /**
-     * @var string
+     * @var null|string
      */
     protected $value;
 
@@ -49,6 +47,7 @@ public static function fromString($headerLine)
         }
 
         $parts     = explode(';', $value);
+        /** @var string $mediaType */
         $mediaType = array_shift($parts);
         $header    = new static($value, trim($mediaType));
 
@@ -168,7 +167,7 @@ public function setMediaType($mediaType)
     /**
      * Get the media type
      *
-     * @return string
+     * @return null|string
      */
     public function getMediaType()
     {
@@ -238,7 +237,7 @@ protected function assembleValue()
     {
         $mediaType = $this->getMediaType();
         if (empty($this->parameters)) {
-            return $mediaType;
+            return $mediaType ?: '';
         }
 
         $parameters = [];
@@ -275,8 +274,8 @@ function (&$value) {
      * - subtype
      * - format
      *
-     * @param  string $string
-     * @return stdClass
+     * @param  null|string $string
+     * @return object
      */
     protected function getMediaTypeObjectFromString($string)
     {
@@ -287,15 +286,18 @@ protected function getMediaTypeObjectFromString($string)
             ));
         }
 
+        /** @var string[] $parts */
         $parts = explode('/', $string, 2);
-        if (1 == count($parts)) {
+        if (1 === count($parts)) {
             throw new Exception\DomainException(sprintf(
                 'Invalid mediatype "%s" provided',
                 $string
             ));
         }
 
+        /** @var string $type */
         $type    = array_shift($parts);
+        /** @var string $subtype */
         $subtype = array_shift($parts);
         $format  = $subtype;
         if (false !== strpos($subtype, '+')) {
@@ -316,8 +318,8 @@ protected function getMediaTypeObjectFromString($string)
     /**
      * Validate a subtype
      *
-     * @param  stdClass $right
-     * @param  stdClass $left
+     * @param  object $right
+     * @param  object $left
      * @return bool
      */
     protected function validateSubtype($right, $left)
@@ -356,17 +358,17 @@ protected function validateSubtype($right, $left)
      *
      * Validate that the right side format matches what the left side defines.
      *
-     * @param  string $right
-     * @param  string $left
+     * @param  object $right
+     * @param  object $left
      * @return bool
      */
     protected function validateFormat($right, $left)
     {
         if ($right->format && $left->format) {
-            if ($right->format == '*') {
+            if ($right->format === '*') {
                 return true;
             }
-            if ($right->format == $left->format) {
+            if ($right->format === $left->format) {
                 return true;
             }
             return false;
diff --git a/src/Header/Cookie.php b/src/Header/Cookie.php
index 3cae6701a0..193397b384 100644
--- a/src/Header/Cookie.php
+++ b/src/Header/Cookie.php
@@ -29,6 +29,13 @@ public static function fromSetCookieArray(array $setCookies)
                 ));
             }
 
+            if (null === $setCookie->getName()) {
+                throw new Exception\InvalidArgumentException(sprintf(
+                    '%s requires cookies with name',
+                    __METHOD__
+                ));
+            }
+
             if (array_key_exists($setCookie->getName(), $nvPairs)) {
                 throw new Exception\InvalidArgumentException(sprintf(
                     'Two cookies with the same name were provided to %s',
@@ -53,12 +60,13 @@ public static function fromString($headerLine)
             throw new Exception\InvalidArgumentException('Invalid header line for Server string: "' . $name . '"');
         }
 
+        /** @var string[] $nvPairs */
         $nvPairs = preg_split('#;\s*#', $value);
 
         $arrayInfo = [];
         foreach ($nvPairs as $nvPair) {
             $parts = explode('=', $nvPair, 2);
-            if (count($parts) != 2) {
+            if (count($parts) !== 2) {
                 throw new Exception\RuntimeException('Malformed Cookie header found');
             }
             list($name, $value) = $parts;
@@ -104,7 +112,7 @@ public function getFieldValue()
         $nvPairs = [];
 
         foreach ($this->flattenCookies($this) as $name => $value) {
-            $nvPairs[] = $name . '=' . (($this->encodeValue) ? urlencode($value) : $value);
+            $nvPairs[] = $name . '=' . ($this->encodeValue ? urlencode($value) : $value);
         }
 
         return implode('; ', $nvPairs);
diff --git a/src/Header/GenericMultiHeader.php b/src/Header/GenericMultiHeader.php
index 18cdab61e4..5c773280b8 100644
--- a/src/Header/GenericMultiHeader.php
+++ b/src/Header/GenericMultiHeader.php
@@ -9,6 +9,10 @@
 
 class GenericMultiHeader extends GenericHeader implements MultipleHeaderInterface
 {
+    /**
+     * @param string $headerLine
+     * @return GenericMultiHeader|GenericMultiHeader[]
+     */
     public static function fromString($headerLine)
     {
         list($fieldName, $fieldValue) = GenericHeader::splitHeaderLine($headerLine);
diff --git a/src/Header/HeaderValue.php b/src/Header/HeaderValue.php
index a0cfe2ba9d..989d80237d 100644
--- a/src/Header/HeaderValue.php
+++ b/src/Header/HeaderValue.php
@@ -26,7 +26,7 @@ private function __construct()
      * between visible characters.
      *
      * @see http://en.wikipedia.org/wiki/HTTP_response_splitting
-     * @param string $value
+     * @param null|string $value
      * @return string
      */
     public static function filter($value)
@@ -63,7 +63,7 @@ public static function filter($value)
      * between visible characters.
      *
      * @see http://en.wikipedia.org/wiki/HTTP_response_splitting
-     * @param string $value
+     * @param null|string $value
      * @return bool
      */
     public static function isValid($value)
@@ -92,7 +92,7 @@ public static function isValid($value)
     /**
      * Assert a header value is valid.
      *
-     * @param string $value
+     * @param null|string $value
      * @throws Exception\RuntimeException for invalid values
      * @return void
      */
diff --git a/src/Header/RetryAfter.php b/src/Header/RetryAfter.php
index 621c6fc448..1aefa93365 100644
--- a/src/Header/RetryAfter.php
+++ b/src/Header/RetryAfter.php
@@ -43,7 +43,7 @@ public static function fromString($headerLine)
         }
 
         if (is_numeric($date)) {
-            $dateHeader->setDeltaSeconds($date);
+            $dateHeader->setDeltaSeconds((int) $date);
         } else {
             $dateHeader->setDate($date);
         }
diff --git a/src/Header/SetCookie.php b/src/Header/SetCookie.php
index 5fbe32af50..ffcbbc5bed 100644
--- a/src/Header/SetCookie.php
+++ b/src/Header/SetCookie.php
@@ -125,7 +125,7 @@ class SetCookie implements MultipleHeaderInterface
     /**
      * @static
      * @throws Exception\InvalidArgumentException
-     * @param  $headerLine
+     * @param  string $headerLine
      * @param  bool $bypassHeaderFieldName
      * @return array|SetCookie
      */
@@ -138,6 +138,7 @@ public static function fromString($headerLine, $bypassHeaderFieldName = false)
             $setCookieProcessor = function ($headerLine) use ($setCookieClass) {
                 /** @var SetCookie $header */
                 $header = new $setCookieClass();
+                /** @var string[] $keyValuePairs */
                 $keyValuePairs = preg_split('#;\s*#', $headerLine);
 
                 foreach ($keyValuePairs as $keyValue) {
@@ -207,17 +208,18 @@ public static function fromString($headerLine, $bypassHeaderFieldName = false)
             throw new Exception\InvalidArgumentException('Invalid header line for Set-Cookie string: "' . $name . '"');
         }
 
+        /** @var string[] $multipleHeaders */
         $multipleHeaders = preg_split('#(?<!Sun|Mon|Tue|Wed|Thu|Fri|Sat),\s*#', $value);
 
         if (count($multipleHeaders) <= 1) {
             return $setCookieProcessor(array_pop($multipleHeaders));
-        } else {
-            $headers = [];
-            foreach ($multipleHeaders as $headerLine) {
-                $headers[] = $setCookieProcessor($headerLine);
-            }
-            return $headers;
         }
+
+        $headers = [];
+        foreach ($multipleHeaders as $headerLine) {
+            $headers[] = $setCookieProcessor($headerLine);
+        }
+        return $headers;
     }
 
     /**
@@ -248,8 +250,6 @@ public function __construct(
         $version = null,
         $sameSite = null
     ) {
-        $this->type = 'Cookie';
-
         $this->setName($name)
              ->setValue($value)
              ->setVersion($version)
@@ -296,7 +296,9 @@ public function getFieldValue()
             return '';
         }
 
-        $value = $this->encodeValue ? urlencode($this->getValue()) : $this->getValue();
+        $value = $this->getValue() ?: '';
+        $value = $this->encodeValue ? urlencode($value) : $value;
+
         if ($this->hasQuoteFieldValue()) {
             $value = '"' . $value . '"';
         }
@@ -405,7 +407,7 @@ public function getVersion()
     }
 
     /**
-     * @param  int $maxAge
+     * @param  int|null $maxAge
      * @return $this
      */
     public function setMaxAge($maxAge)
@@ -567,7 +569,7 @@ public function setHttponly($httponly)
     /**
      * @return bool|null
      */
-    public function isHttponly()
+    public function isHttpOnly()
     {
         return $this->httponly;
     }
@@ -646,11 +648,13 @@ public function hasQuoteFieldValue()
      */
     public function isValidForRequest($requestDomain, $path, $isSecure = false)
     {
-        if ($this->getDomain() && (strrpos($requestDomain, $this->getDomain()) === false)) {
+        $cookieDomain = $this->getDomain();
+        if ($cookieDomain && (strrpos($requestDomain, $cookieDomain) === false)) {
             return false;
         }
 
-        if ($this->getPath() && (strpos($path, $this->getPath()) !== 0)) {
+        $cookiePath = $this->getPath();
+        if ($cookiePath && (strpos($path, $cookiePath) !== 0)) {
             return false;
         }
 
@@ -677,12 +681,12 @@ public function match($uri, $matchSessionCookies = true, $now = null)
         }
 
         // Make sure we have a valid Zend_Uri_Http object
-        if (! ($uri->isValid() && ($uri->getScheme() == 'http' || $uri->getScheme() == 'https'))) {
+        if (! ($uri->isValid() && ($uri->getScheme() === 'http' || $uri->getScheme() === 'https'))) {
             throw new Exception\InvalidArgumentException('Passed URI is not a valid HTTP or HTTPS URI');
         }
 
         // Check that the cookie is secure (if required) and not expired
-        if ($this->secure && $uri->getScheme() != 'https') {
+        if ($this->secure && $uri->getScheme() !== 'https') {
             return false;
         }
         if ($this->isExpired($now)) {
@@ -693,11 +697,15 @@ public function match($uri, $matchSessionCookies = true, $now = null)
         }
 
         // Check if the domain matches
-        if (! self::matchCookieDomain($this->getDomain(), $uri->getHost())) {
+        if (! self::matchCookieDomain($this->getDomain() ?: '', $uri->getHost() ?: '')) {
             return false;
         }
 
         // Check that path matches using prefix match
+        if (null === $this->getPath() || null === $uri->getPath()) {
+            return false;
+        }
+
         if (! self::matchCookiePath($this->getPath(), $uri->getPath())) {
             return false;
         }
diff --git a/src/Headers.php b/src/Headers.php
index 96153c2b83..0a285953ba 100644
--- a/src/Headers.php
+++ b/src/Headers.php
@@ -14,6 +14,7 @@
 use Zend\Http\Header\Exception;
 use Zend\Http\Header\GenericHeader;
 use Zend\Loader\PluginClassLocator;
+use Zend\Http\Header\MultipleHeaderInterface;
 
 /**
  * Basic HTTP headers collection functionality
@@ -68,13 +69,13 @@ public static function fromString($string)
                 continue;
             }
 
-            if ($emptyLine) {
+            if ($emptyLine > 0) {
                 throw new Exception\RuntimeException('Malformed header detected');
             }
 
             // check if a header name is present
             if (preg_match('/^(?P<name>[^()><@,;:\"\\/\[\]?={} \t]+):.*$/', $line, $matches)) {
-                if ($current) {
+                if (isset($current['name'])) {
                     // a header name was present, then store the current complete line
                     $headers->headersKeys[] = static::createKey($current['name']);
                     $headers->headers[]     = $current;
@@ -89,8 +90,10 @@ public static function fromString($string)
 
             if (preg_match("/^[ \t][^\r\n]*$/", $line, $matches)) {
                 // continuation: append to current line
-                $current['line'] .= trim($line);
-                continue;
+                if (isset($current['line'])) {
+                    $current['line'] .= trim($line);
+                    continue;
+                }
             }
 
             // Line does not match header format!
@@ -99,7 +102,8 @@ public static function fromString($string)
                 $line
             ));
         }
-        if ($current) {
+
+        if (isset($current['name'])) {
             $headers->headersKeys[] = static::createKey($current['name']);
             $headers->headers[]     = $current;
         }
@@ -154,7 +158,9 @@ public function addHeaders($headers)
                 if (is_string($value)) {
                     $this->addHeaderLine($value);
                 } elseif (is_array($value) && count($value) == 1) {
-                    $this->addHeaderLine(key($value), current($value));
+                    /** @var string */
+                    $key = key($value);
+                    $this->addHeaderLine($key, current($value));
                 } elseif (is_array($value) && count($value) == 2) {
                     $this->addHeaderLine($value[0], $value[1]);
                 } elseif ($value instanceof Header\HeaderInterface) {
@@ -282,9 +288,9 @@ public function get($name)
             return false;
         }
 
-        $class = ($this->getPluginClassLoader()->load(str_replace('-', '', $key))) ?: 'Zend\Http\Header\GenericHeader';
+        $class = ($this->getPluginClassLoader()->load(str_replace('-', '', $key))) ?: GenericHeader::class;
 
-        if (in_array('Zend\Http\Header\MultipleHeaderInterface', class_implements($class, true))) {
+        if (in_array(MultipleHeaderInterface::class, class_implements($class, true))) {
             $headers = [];
             foreach (array_keys($this->headersKeys, $key) as $index) {
                 if (is_array($this->headers[$index])) {
@@ -368,8 +374,9 @@ public function rewind()
     public function current()
     {
         $current = current($this->headers);
-        if (is_array($current)) {
-            $current = $this->lazyLoadHeader(key($this->headers));
+        $key = key($this->headers);
+        if (null !== $key && is_array($current)) {
+            $current = $this->lazyLoadHeader($key);
         }
         return $current;
     }
@@ -452,9 +459,9 @@ public function forceLoading()
     }
 
     /**
-     * @param $index
+     * @param string|int $index
      * @param bool $isGeneric If true, there is no need to parse $index and call the ClassLoader.
-     * @return mixed|void
+     * @return Header\HeaderInterface
      */
     protected function lazyLoadHeader($index, $isGeneric = false)
     {
diff --git a/src/PhpEnvironment/RemoteAddress.php b/src/PhpEnvironment/RemoteAddress.php
index 65a001993a..1d8dde2327 100644
--- a/src/PhpEnvironment/RemoteAddress.php
+++ b/src/PhpEnvironment/RemoteAddress.php
@@ -94,6 +94,7 @@ public function setProxyHeader($header = 'X-Forwarded-For')
      */
     public function getIpAddress()
     {
+        /** @var string|false $ip */
         $ip = $this->getIpAddressFromProxy();
         if ($ip) {
             return $ip;
@@ -111,7 +112,7 @@ public function getIpAddress()
      * Attempt to get the IP address for a proxied client
      *
      * @see http://tools.ietf.org/html/draft-ietf-appsawg-http-forwarded-10#section-5.2
-     * @return false|string
+     * @return bool|string
      */
     protected function getIpAddressFromProxy()
     {
@@ -131,6 +132,7 @@ protected function getIpAddressFromProxy()
         // trim, so we can compare against trusted proxies properly
         $ips = array_map('trim', $ips);
         // remove trusted proxy IPs
+        /** @var string[] $ips */
         $ips = array_diff($ips, $this->trustedProxies);
 
         // Any left?
diff --git a/src/PhpEnvironment/Request.php b/src/PhpEnvironment/Request.php
index 4101af1752..b929a5d1dc 100644
--- a/src/PhpEnvironment/Request.php
+++ b/src/PhpEnvironment/Request.php
@@ -8,6 +8,8 @@
 namespace Zend\Http\PhpEnvironment;
 
 use Zend\Http\Header\Cookie;
+use Zend\Http\Header\HeaderInterface;
+use Zend\Http\Headers;
 use Zend\Http\Request as HttpRequest;
 use Zend\Stdlib\Parameters;
 use Zend\Stdlib\ParametersInterface;
@@ -93,7 +95,7 @@ public function getContent()
     {
         if (empty($this->content)) {
             $requestBody = file_get_contents('php://input');
-            if (strlen($requestBody) > 0) {
+            if ($requestBody && strlen($requestBody) > 0) {
                 $this->content = $requestBody;
             }
         }
@@ -106,12 +108,14 @@ public function getContent()
      *
      * Instantiate and set cookies.
      *
-     * @param $cookie
+     * @param ParametersInterface $cookie
      * @return $this
      */
     public function setCookies($cookie)
     {
-        $this->getHeaders()->addHeader(new Cookie((array) $cookie));
+        /** @var Headers $headers */
+        $headers = $this->getHeaders();
+        $headers->addHeader(new Cookie((array) $cookie));
         return $this;
     }
 
@@ -205,7 +209,7 @@ public function setServer(ParametersInterface $server)
         // This seems to be the only way to get the Authorization header on Apache
         if (function_exists('apache_request_headers')) {
             $apacheRequestHeaders = apache_request_headers();
-            if (! isset($this->serverParams['HTTP_AUTHORIZATION'])) {
+            if (false !== $apacheRequestHeaders && ! isset($this->serverParams['HTTP_AUTHORIZATION'])) {
                 if (isset($apacheRequestHeaders['Authorization'])) {
                     $this->serverParams->set('HTTP_AUTHORIZATION', $apacheRequestHeaders['Authorization']);
                 } elseif (isset($apacheRequestHeaders['authorization'])) {
@@ -215,7 +219,7 @@ public function setServer(ParametersInterface $server)
         }
 
         // set headers
-        $headers = [];
+        $headersArray = [];
 
         foreach ($server as $key => $value) {
             if ($value || (! is_array($value) && strlen($value))) {
@@ -225,15 +229,17 @@ public function setServer(ParametersInterface $server)
                         continue;
                     }
 
-                    $headers[strtr(ucwords(strtolower(strtr(substr($key, 5), '_', ' '))), ' ', '-')] = $value;
+                    $headersArray[strtr(ucwords(strtolower(strtr(substr($key, 5), '_', ' '))), ' ', '-')] = $value;
                 } elseif (strpos($key, 'CONTENT_') === 0) {
                     $name = substr($key, 8); // Remove "Content-"
-                    $headers['Content-' . (($name == 'MD5') ? $name : ucfirst(strtolower($name)))] = $value;
+                    $headersArray['Content-' . (($name === 'MD5') ? $name : ucfirst(strtolower($name)))] = $value;
                 }
             }
         }
 
-        $this->getHeaders()->addHeaders($headers);
+        /** @var Headers $headers */
+        $headers = $this->getHeaders();
+        $headers->addHeaders($headersArray);
 
         // set method
         if (isset($this->serverParams['REQUEST_METHOD'])) {
@@ -266,9 +272,10 @@ public function setServer(ParametersInterface $server)
         $port = null;
 
         // Set the host
-        $headerHost = $this->getHeaders()->get('host');
-        if ($headerHost) {
-            $host = $headerHost->getFieldValue();
+        /** @var false|HeaderInterface $hostHeader */
+        $hostHeader = $headers->get('host');
+        if ($hostHeader) {
+            $host = $hostHeader->getFieldValue();
 
             // works for regname, IPv4 & IPv6
             if (preg_match('|\:(\d+)$|', $host, $matches)) {
@@ -310,7 +317,8 @@ public function setServer(ParametersInterface $server)
 
         // URI path
         $requestUri = $this->getRequestUri();
-        if (($qpos = strpos($requestUri, '?')) !== false) {
+        $qpos = strpos($requestUri, '?');
+        if ($qpos !== false) {
             $requestUri = substr($requestUri, 0, $qpos);
         }
 
@@ -448,7 +456,9 @@ protected function detectRequestUri()
         // HTTP proxy requests setup request URI with scheme and host [and port]
         // + the URL path, only use URL path.
         if ($requestUri !== null) {
-            return preg_replace('#^[^/:]+://[^/]+#', '', $requestUri);
+            /** @var string $uri */
+            $uri = preg_replace('#^[^/:]+://[^/]+#', '', $requestUri);
+            return $uri;
         }
 
         // IIS 5.0, PHP as CGI.
@@ -529,7 +539,8 @@ protected function detectBaseUrl()
 
         $truncatedRequestUri = $requestUri;
 
-        if (false !== ($pos = strpos($requestUri, '?'))) {
+        $pos = strpos($requestUri, '?');
+        if (false !== $pos) {
             $truncatedRequestUri = substr($requestUri, 0, $pos);
         }
 
diff --git a/src/PhpEnvironment/Response.php b/src/PhpEnvironment/Response.php
index 0a926b20c1..294b12352b 100644
--- a/src/PhpEnvironment/Response.php
+++ b/src/PhpEnvironment/Response.php
@@ -96,7 +96,6 @@ public function sendHeaders()
             header($header->toString());
         }
 
-        $this->headersSent = true;
         return $this;
     }
 
diff --git a/src/Request.php b/src/Request.php
index 8b9cd6f277..bb7d70364a 100644
--- a/src/Request.php
+++ b/src/Request.php
@@ -7,6 +7,7 @@
 
 namespace Zend\Http;
 
+use Zend\Http\Header\HeaderInterface;
 use Zend\Stdlib\Parameters;
 use Zend\Stdlib\ParametersInterface;
 use Zend\Stdlib\RequestInterface;
@@ -100,6 +101,7 @@ public static function fromString($string, $allowCustomMethods = true)
             );
 
         $regex     = '#^(?P<method>' . $methods . ')\s(?P<uri>[^ ]*)(?:\sHTTP\/(?P<version>\d+\.\d+)){0,1}#';
+        /** @var string $firstLine */
         $firstLine = array_shift($lines);
         if (! preg_match($regex, $firstLine, $matches)) {
             throw new Exception\InvalidArgumentException(
@@ -111,6 +113,13 @@ public static function fromString($string, $allowCustomMethods = true)
         $request->setUri($matches['uri']);
 
         $parsedUri = parse_url($matches['uri']);
+
+        if (false === $parsedUri) {
+            throw new Exception\InvalidArgumentException(
+                'A valid request line was not found in the provided string'
+            );
+        }
+
         if (array_key_exists('query', $parsedUri)) {
             $parsedQuery = [];
             parse_str($parsedUri['query'], $parsedQuery);
@@ -128,6 +137,7 @@ public static function fromString($string, $allowCustomMethods = true)
         $isHeader = true;
         $headers = $rawBody = [];
         while ($lines) {
+            /** @var string $nextLine */
             $nextLine = array_shift($lines);
             if ($nextLine == '') {
                 $isHeader = false;
@@ -213,6 +223,13 @@ public function setUri($uri)
                 'URI must be an instance of Zend\Uri\Http or a string'
             );
         }
+
+        $path = $uri->getPath();
+
+        if (empty($path)) {
+            $uri->setPath('/');
+        }
+
         $this->uri = $uri;
 
         return $this;
@@ -318,7 +335,12 @@ public function getPost($name = null, $default = null)
      */
     public function getCookie()
     {
-        return $this->getHeaders()->get('Cookie');
+        /** @var Headers $headers */
+        $headers = $this->getHeaders();
+        /** @var false|Header\Cookie $header */
+        $header = $headers->get('Cookie');
+
+        return $header;
     }
 
     /**
@@ -366,7 +388,7 @@ public function getHeaders($name = null, $default = false)
     {
         if ($this->headers === null || is_string($this->headers)) {
             // this is only here for fromString lazy loading
-            $this->headers = (is_string($this->headers)) ? Headers::fromString($this->headers) : new Headers();
+            $this->headers = is_string($this->headers) ? Headers::fromString($this->headers) : new Headers();
         }
 
         if ($name === null) {
@@ -390,7 +412,10 @@ public function getHeaders($name = null, $default = false)
      */
     public function getHeader($name, $default = false)
     {
-        return $this->getHeaders($name, $default);
+        /** @var false|HeaderInterface $header */
+        $header = $this->getHeaders($name, $default);
+
+        return $header;
     }
 
     /**
@@ -502,8 +527,11 @@ public function isPatch()
      */
     public function isXmlHttpRequest()
     {
-        $header = $this->getHeaders()->get('X_REQUESTED_WITH');
-        return false !== $header && $header->getFieldValue() == 'XMLHttpRequest';
+        /** @var Headers $headers */
+        $headers = $this->getHeaders();
+        /** @var false|HeaderInterface $header */
+        $header = $headers->get('X_REQUESTED_WITH');
+        return false !== $header && $header->getFieldValue() === 'XMLHttpRequest';
     }
 
     /**
@@ -513,7 +541,10 @@ public function isXmlHttpRequest()
      */
     public function isFlashRequest()
     {
-        $header = $this->getHeaders()->get('USER_AGENT');
+        /** @var Headers $headers */
+        $headers = $this->getHeaders();
+        /** @var false|HeaderInterface $header */
+        $header = $headers->get('USER_AGENT');
         return false !== $header && stristr($header->getFieldValue(), ' flash');
     }
 
@@ -532,8 +563,10 @@ public function renderRequestLine()
      */
     public function toString()
     {
+        /** @var Headers $headers */
+        $headers = $this->getHeaders();
         $str = $this->renderRequestLine() . "\r\n";
-        $str .= $this->getHeaders()->toString();
+        $str .= $headers->toString();
         $str .= "\r\n";
         $str .= $this->getContent();
         return $str;
diff --git a/src/Response.php b/src/Response.php
index a64dbf3d07..64a25a8466 100644
--- a/src/Response.php
+++ b/src/Response.php
@@ -7,7 +7,8 @@
 
 namespace Zend\Http;
 
-use Zend\Http\Exception\RuntimeException;
+use Zend\Http\Exception\InvalidArgumentException;
+use Zend\Http\Header\HeaderInterface;
 use Zend\Stdlib\ErrorHandler;
 use Zend\Stdlib\ResponseInterface;
 
@@ -197,6 +198,7 @@ public static function fromString($string)
             $lines = explode("\n", $string);
         }
 
+        /** @var string $firstLine */
         $firstLine = array_shift($lines);
 
         $response = new static();
@@ -208,6 +210,9 @@ public static function fromString($string)
         if ($response->statusCode === static::STATUS_CODE_100) {
             $next = array_shift($lines); // take next line
             $next = empty($next) ? array_shift($lines) : $next; // take next or skip if empty
+            if (null === $next) {
+                throw new Exception\InvalidArgumentException('Invalid response content');
+            }
             $response->parseStatusLine($next);
         }
 
@@ -273,11 +278,14 @@ protected function parseStatusLine($line)
     }
 
     /**
-     * @return Header\SetCookie[]
+     * @return bool|Header\SetCookie[]
      */
     public function getCookie()
     {
-        return $this->getHeaders()->get('Set-Cookie');
+        /** @var false|Header\SetCookie[] $header */
+        $header = $this->getHeaders()->get('Set-Cookie');
+
+        return $header;
     }
 
     /**
@@ -361,7 +369,7 @@ public function setReasonPhrase($reasonPhrase)
     /**
      * Get HTTP status message
      *
-     * @return string
+     * @return null|string
      */
     public function getReasonPhrase()
     {
@@ -380,14 +388,17 @@ public function getBody()
     {
         $body = (string) $this->getContent();
 
+        /** @var false|HeaderInterface $transferEncoding */
         $transferEncoding = $this->getHeaders()->get('Transfer-Encoding');
 
         if (! empty($transferEncoding)) {
-            if (strtolower($transferEncoding->getFieldValue()) === 'chunked') {
+            $transferEncoding = $transferEncoding->getFieldValue();
+            if (strtolower($transferEncoding) === 'chunked') {
                 $body = $this->decodeChunkedBody($body);
             }
         }
 
+        /** @var false|HeaderInterface $contentEncoding */
         $contentEncoding = $this->getHeaders()->get('Content-Encoding');
 
         if (! empty($contentEncoding)) {
@@ -552,7 +563,7 @@ protected function decodeChunkedBody($body)
                 break;
             }
 
-            $length   = hexdec(trim($m[1]));
+            $length   = (int) hexdec(trim($m[1]));
             $cut      = strlen($m[0]);
             $decBody .= substr($body, $offset + $cut, $length);
             $offset += $cut + $length + 2;
@@ -578,9 +589,10 @@ protected function decodeGzip($body)
             );
         }
 
+        $contentLengthHeader = $this->getHeaders()->get('content-length');
         if ($body === ''
-            || ($this->getHeaders()->has('content-length')
-                && (int) $this->getHeaders()->get('content-length')->getFieldValue() === 0)
+            || ($contentLengthHeader instanceof Header\ContentLength
+                && (int) $contentLengthHeader->getFieldValue() === 0)
         ) {
             return '';
         }
@@ -588,7 +600,7 @@ protected function decodeGzip($body)
         ErrorHandler::start();
         $return = gzinflate(substr($body, 10));
         $test = ErrorHandler::stop();
-        if ($test) {
+        if ($test || false === $return) {
             throw new Exception\RuntimeException(
                 'Error occurred during gzip inflation',
                 0,
@@ -615,8 +627,9 @@ protected function decodeDeflate($body)
             );
         }
 
-        if ($this->getHeaders()->has('content-length')
-            && 0 === (int) $this->getHeaders()->get('content-length')->getFieldValue()) {
+        $contentLengthHeader = $this->getHeaders()->get('content-length');
+        if ($contentLengthHeader instanceof Header\ContentLength
+            && 0 === (int) $contentLengthHeader->getFieldValue()) {
             return '';
         }
 
@@ -634,8 +647,17 @@ protected function decodeDeflate($body)
         $zlibHeader = unpack('n', substr($body, 0, 2));
 
         if ($zlibHeader[1] % 31 === 0) {
-            return gzuncompress($body);
+            $uncompressed = gzuncompress($body);
+        } else {
+            $uncompressed = gzinflate($body);
+        }
+
+        if (false === $uncompressed) {
+            throw new Exception\RuntimeException(
+                'An error occurred during inflation'
+            );
         }
-        return gzinflate($body);
+
+        return $uncompressed;
     }
 }
diff --git a/src/Response/Stream.php b/src/Response/Stream.php
index 371c0cc35e..3833b87ed6 100644
--- a/src/Response/Stream.php
+++ b/src/Response/Stream.php
@@ -19,7 +19,7 @@ class Stream extends Response
     /**
      * The Content-Length value, if set
      *
-     * @var int
+     * @var null|int
      */
     protected $contentLength;
 
@@ -33,7 +33,7 @@ class Stream extends Response
     /**
      * Response as stream
      *
-     * @var resource
+     * @var null|resource
      */
     protected $stream;
 
@@ -42,7 +42,7 @@ class Stream extends Response
      *
      * Will be empty if stream is not file-based.
      *
-     * @var string
+     * @var null|string
      */
     protected $streamName;
 
@@ -51,7 +51,7 @@ class Stream extends Response
      *
      * @var bool
      */
-    protected $cleanup;
+    protected $cleanup = false;
 
     /**
      * Set content length
@@ -76,7 +76,7 @@ public function getContentLength()
     /**
      * Get the response as stream
      *
-     * @return resource
+     * @return null|resource
      */
     public function getStream()
     {
@@ -118,7 +118,7 @@ public function setCleanup($cleanup = true)
     /**
      * Get file name associated with the stream
      *
-     * @return string
+     * @return null|string
      */
     public function getStreamName()
     {
@@ -161,22 +161,25 @@ public static function fromStream($responseString, $stream)
         }
 
         while (! empty($responseArray)) {
+            /** @var string $nextLine */
             $nextLine        = array_shift($responseArray);
             $headersString  .= $nextLine . "\n";
             $nextLineTrimmed = trim($nextLine);
-            if ($nextLineTrimmed == '') {
+            if ($nextLineTrimmed === '') {
                 $headerComplete = true;
                 break;
             }
         }
 
         if (! $headerComplete) {
-            while (false !== ($nextLine = fgets($stream))) {
+            $nextLine = fgets($stream);
+            while (false !== $nextLine) {
                 $headersString .= trim($nextLine) . "\r\n";
-                if ($nextLine == "\r\n" || $nextLine == "\n") {
+                if ($nextLine === "\r\n" || $nextLine === "\n") {
                     $headerComplete = true;
                     break;
                 }
+                $nextLine = fgets($stream);
             }
         }
 
@@ -266,14 +269,14 @@ protected function readStream()
             $bytes = -1; // Read the whole buffer
         }
 
-        if (! is_resource($this->stream) || $bytes == 0) {
+        if (! is_resource($this->stream) || $bytes === 0) {
             return '';
         }
 
         $this->content         .= stream_get_contents($this->stream, $bytes);
         $this->contentStreamed += strlen($this->content);
 
-        if ($this->getContentLength() == $this->contentStreamed) {
+        if ($this->getContentLength() === $this->contentStreamed) {
             $this->stream = null;
         }
     }
@@ -286,7 +289,7 @@ public function __destruct()
         if (is_resource($this->stream)) {
             $this->stream = null; //Could be listened by others
         }
-        if ($this->cleanup) {
+        if ($this->cleanup && $this->streamName) {
             ErrorHandler::start(E_WARNING);
             unlink($this->streamName);
             ErrorHandler::stop();
diff --git a/test/ClientTest.php b/test/ClientTest.php
index 1efbb45b83..6da7259de9 100644
--- a/test/ClientTest.php
+++ b/test/ClientTest.php
@@ -9,6 +9,7 @@
 
 use ArrayIterator;
 use PHPUnit\Framework\TestCase;
+use ReflectionClass;
 use ReflectionMethod;
 use Zend\Http\Client;
 use Zend\Http\Client\Adapter\AdapterInterface;
@@ -24,10 +25,30 @@
 use Zend\Http\Request;
 use Zend\Http\Response;
 use Zend\Uri\Http;
+use Zend\Stdlib;
 use ZendTest\Http\TestAsset\ExtendedClient;
 
 class ClientTest extends TestCase
 {
+    private $originalErrorReporting;
+    private $tmpDir;
+
+    protected function setUp()
+    {
+        $this->originalErrorReporting = \error_reporting();
+        $this->tmpDir = \getenv('TMPDIR');
+
+        parent::setUp();
+    }
+
+    protected function tearDown()
+    {
+        \error_reporting($this->originalErrorReporting);
+        \putenv('TMPDIR=' . $this->tmpDir);
+
+        parent::tearDown();
+    }
+
     public function testIfCookiesAreSticky()
     {
         $initialCookies = [
@@ -119,6 +140,8 @@ public function testIfZeroValueCookiesCanBeSet()
         $client->addCookie('test', 0);
         $client->addCookie('test2', '0');
         $client->addCookie('test3', false);
+
+        $this->assertCount(3, $client->getCookies());
     }
 
     public function testIfNullValueCookiesThrowsException()
@@ -179,6 +202,17 @@ public function testArgSeparatorDefaultsToIniSetting()
         $this->assertEquals($argSeparator, $client->getArgSeparator());
     }
 
+    /**
+     * @group 2774
+     * @group 2745
+     */
+    public function testArgSeparatorDefaultsWithNoIniSetting()
+    {
+        \ini_set('arg_separator.output', false);
+        $client = new Client();
+        $this->assertEquals('&', $client->getArgSeparator());
+    }
+
     /**
      * @group 2774
      * @group 2745
@@ -192,7 +226,7 @@ public function testCanOverrideArgSeparator()
 
     public function testClientUsesAcceptEncodingHeaderFromRequestObject()
     {
-        $client = new Client();
+        $client = new Client('http://foo.com');
 
         $client->setAdapter(Test::class);
 
@@ -266,6 +300,75 @@ public function testIfMaxredirectWorksCorrectly()
         $this->assertEquals($response->getContent(), 'Page #2');
     }
 
+    public function testSendWithNotUriPath()
+    {
+        $testAdapter = new Test();
+        $testAdapter->setResponse(
+            'HTTP/1.1 200 OK' . "\r\n\r\n"
+            . 'Page #1'
+        );
+
+        $uri = new Http();
+        $uri->setHost('www.example.org');
+
+        $this->assertNull($uri->getPath());
+
+        $client = new Client($uri, [
+            'adapter' => $testAdapter,
+            'storeresponse' => true,
+        ]);
+
+        // do the request
+        $response = $client->setMethod('GET')->send();
+
+        $this->assertEquals($response->getContent(), 'Page #1');
+    }
+
+    public function testHappyPathWithDispatch()
+    {
+        $testAdapter = new Test();
+        $testAdapter->setResponse(
+            'HTTP/1.1 200 OK' . "\r\n\r\n"
+            . 'Page #1'
+        );
+
+        $client = new Client('http://www.example.org/part1', [
+            'adapter' => $testAdapter,
+            'storeresponse' => true,
+        ]);
+
+        $request = new Request();
+        $request->setUri('http://www.example.org/part1');
+        $response = new Response();
+
+        // do the request
+        $response = $client->setMethod('GET')->dispatch($request, $response);
+
+        $this->assertEquals($response->getContent(), 'Page #1');
+    }
+
+    public function testDispatchWithBaseInterface()
+    {
+        $this->expectException(HttpException\UnexpectedValueException::class);
+
+        $testAdapter = new Test();
+        $testAdapter->setResponse(
+            'HTTP/1.1 200 OK' . "\r\n\r\n"
+            . 'Page #1'
+        );
+
+        $client = new Client('http://www.example.org/part1', [
+            'adapter' => $testAdapter,
+            'storeresponse' => true,
+        ]);
+
+        $request = $this->prophesize(Stdlib\RequestInterface::class);
+        $response = new Response();
+
+        // do the request
+        $client->setMethod('GET')->dispatch($request->reveal(), $response);
+    }
+
     public function testIfClientDoesNotLooseAuthenticationOnRedirect()
     {
         // set up user credentials
@@ -486,6 +589,7 @@ public function testHttpQueryParametersCastToString()
     public function testClientRequestMethod()
     {
         $request = new Request();
+        $request->setUri('http://foo.com');
         $request->setMethod(Request::METHOD_POST);
         $request->getPost()->set('data', 'random');
 
@@ -507,7 +611,7 @@ public function testAllowsClearingEncType()
         $this->assertEquals('application/x-www-form-urlencoded', $client->getEncType());
 
         $client->setEncType(null);
-        $this->assertNull($client->getEncType());
+        $this->assertSame('', $client->getEncType());
     }
 
     /**
@@ -518,6 +622,7 @@ public function testFormUrlEncodeSeparator()
         $client = new Client();
         $client->setEncType('application/x-www-form-urlencoded');
         $request = new Request();
+        $request->setUri('http://foo.com');
         $request->setMethod(Request::METHOD_POST);
         $request->getPost()->set('foo', 'bar');
         $request->getPost()->set('baz', 'foo');
@@ -528,25 +633,30 @@ public function testFormUrlEncodeSeparator()
         $this->assertContains('foo=bar&baz=foo', $rawRequest);
     }
 
-    public function uriDataProvider()
+    public function testRelativeUriInConstructorIsNotAllowed()
     {
-        return [
-            'valid-relative' => ['/example', true],
-            'invalid-absolute' => ['http://localhost/example', false],
-        ];
+        $this->expectException(HttpException\InvalidArgumentException::class);
+        $client = new Client('/example');
     }
 
-    /**
-     * @dataProvider uriDataProvider
-     */
-    public function testUriCorrectlyDeterminesWhetherOrNotItIsAValidRelativeUri($uri, $isValidRelativeURI)
+    public function testRelativeUriIsNotAllowed()
+    {
+        $this->expectException(HttpException\InvalidArgumentException::class);
+        $client = new Client('http://www.domain.com');
+        $client->setUri('/example');
+    }
+
+    public function testRelativeUriIsNotAllowedSendingRequest()
     {
-        $client = new Client($uri);
-        $this->assertSame($isValidRelativeURI, $client->getUri()->isValidRelative());
+        $this->expectException(HttpException\InvalidArgumentException::class);
 
+        $client = new Client();
+        $uri = new Http();
+        $request = new Request();
+        $request->setUri($uri);
+        $request->setMethod(Request::METHOD_GET);
         $client->setAdapter(Test::class);
-        $client->send();
-        $this->assertSame($isValidRelativeURI, $client->getUri()->isValidRelative());
+        $client->send($request);
     }
 
     public function portChangeDataProvider()
@@ -637,4 +747,151 @@ public function testStreamCompression(AdapterInterface $adapter)
 
         self::assertSame($response->getBody(), file_get_contents($tmpFile));
     }
+
+    public function testClientRequestWillNotThrowExceptionOnResponseWithNoCookies()
+    {
+        $request = new Request();
+        $request->setUri('http://www.domain.com');
+        $request->setMethod(Request::METHOD_POST);
+        $request->getPost()->set('data', 'random');
+
+        $response = new Response();
+
+        $adapter = new Test();
+
+        $adapter->setResponse([
+            0 => $response,
+        ]);
+
+        $client = new Client();
+        $client->setAdapter($adapter);
+        $client->send($request);
+
+        $this->assertCount(0, $client->getCookies());
+    }
+
+    public function testClientRequestWillSaveCookiesAndReuseThem()
+    {
+        $cookies = new Cookies();
+        $cookies->addCookie(new SetCookie('foo', 'far', null, '/', 'www.domain.com'));
+        $cookies->addCookie(new SetCookie('bar', 'far', null, '/', 'www.domain.com'));
+
+        $request = new Request();
+        $request->setUri('http://www.domain.com');
+        $request->setMethod(Request::METHOD_POST);
+        $request->getPost()->set('data', 'random');
+
+        $response = new Response();
+        $response->getHeaders()->addHeaders($cookies->getAllCookies());
+
+        $adapter = new Test();
+
+        $adapter->setResponse([
+            0 => $response,
+        ]);
+
+        $client = new Client();
+        $client->setAdapter($adapter);
+        $client->send($request);
+
+        $this->assertCount(2, $client->getCookies());
+
+        $request2 = new Request();
+        $request2->setUri('http://www.domain.com');
+
+        $client->send($request2);
+
+        $lastRawRequest = $client->getLastRawRequest();
+        $this->assertContains("\r\nCookie: foo=far; bar=far\r\n", $lastRawRequest);
+    }
+
+    public function testClientRequestWillSaveCookiesAndReuseThemWithNullPathUri()
+    {
+        $cookies = new Cookies();
+        $cookies->addCookie(new SetCookie('foo', 'far', null, '/', 'www.domain.com'));
+        //$cookies->addCookie(new SetCookie('foo2', 'far', null, '/foo', 'www.domain.com'));
+        $cookies->addCookie(new SetCookie('bar', 'far', null, '/', 'www.domain.com'));
+
+        $uri = new Http();
+        $uri->setHost('www.domain.com');
+
+        $this->assertNull($uri->getPath());
+
+        $request = new Request();
+        $request->setUri('http://www.domain.com');
+        $request->setMethod(Request::METHOD_POST);
+        $request->getPost()->set('data', 'random');
+
+        $response = new Response();
+        $response->getHeaders()->addHeaders($cookies->getAllCookies());
+
+        $adapter = new Test();
+
+        $adapter->setResponse([
+            0 => $response,
+        ]);
+
+        $client = new Client();
+        $client->setAdapter($adapter);
+        $client->send($request);
+
+        $this->assertCount(2, $client->getCookies());
+
+        $request2 = new Request();
+        $request2->setUri($uri);
+
+        $client->send($request2);
+
+        $lastRawRequest = $client->getLastRawRequest();
+        $this->assertContains("\r\nCookie: foo=far; bar=far\r\n", $lastRawRequest);
+    }
+
+    public function testClientRequestWillNotReuseCookiesFromDifferentDomain()
+    {
+        $cookies = new Cookies();
+        $cookies->addCookie(new SetCookie('foo', 'far', null, '/', 'www.domain.com'));
+        $cookies->addCookie(new SetCookie('bar', 'far', null, '/', 'www.domain.com'));
+
+        $request = new Request();
+        $request->setUri('http://www.domain.com');
+        $request->setMethod(Request::METHOD_POST);
+        $request->getPost()->set('data', 'random');
+
+        $response = new Response();
+        $response->getHeaders()->addHeaders($cookies->getAllCookies());
+
+        $adapter = new Test();
+
+        $adapter->setResponse([
+            0 => $response,
+        ]);
+
+        $client = new Client();
+        $client->setAdapter($adapter);
+        $client->send($request);
+
+        $this->assertCount(2, $client->getCookies());
+
+        $request2 = new Request();
+        $request2->setUri('http://foo.com');
+
+        $client->send($request2);
+
+        $lastRawRequest = $client->getLastRawRequest();
+        $this->assertNotContains("\r\nCookie: foo=far; bar=far\r\n", $lastRawRequest);
+    }
+
+    public function testDoRequestWithNoHostUri()
+    {
+        $this->expectException(HttpException\InvalidArgumentException::class);
+
+        $client = new Client();
+        $class = new ReflectionClass(Client::class);
+        $method = $class->getMethod('doRequest');
+        $method->setAccessible(true);
+
+        $uri = new Http();
+
+        $method->invokeArgs($client, [$uri, 'GET']);
+    }
 }
diff --git a/test/CookiesTest.php b/test/CookiesTest.php
index 75e10f8297..d39e28bda8 100644
--- a/test/CookiesTest.php
+++ b/test/CookiesTest.php
@@ -44,6 +44,49 @@ public function testFromResponseInCookie()
         $this->assertSame($header, $response->getCookie('http://www.zend.com', 'foo'));
     }
 
+    public function testGetAllCookiesStringObject()
+    {
+        $response = new Response();
+        $headers = new Headers();
+        $header = new SetCookie('foo', 'bar');
+        $header->setDomain('www.zend.com');
+        $header->setPath('/');
+        $header2 = new SetCookie('foo2', 'bar2');
+        $header2->setDomain('www.zend2.com');
+        $header2->setPath('/');
+        $headers->addHeader($header);
+        $headers->addHeader($header2);
+        $response->setHeaders($headers);
+
+        $response = Cookies::fromResponse($response, 'http://www.zend.com');
+        $result = $response->getAllCookies(Cookies::COOKIE_OBJECT);
+        $this->assertSame([$header, $header2], $result);
+    }
+
+    public function testGetAllCookiesStringArray()
+    {
+        $response = new Response();
+        $headers = new Headers();
+        $header = new SetCookie('foo', 'bar');
+        $header->setDomain('www.zend.com');
+        $header->setPath('/');
+        $header2 = new SetCookie('foo2', 'bar2');
+        $header2->setDomain('www.zend2.com');
+        $header2->setPath('/');
+        $headers->addHeader($header);
+        $headers->addHeader($header2);
+        $response->setHeaders($headers);
+
+        $expected = [
+            'Set-Cookie: foo=bar; Domain=www.zend.com; Path=/',
+            'Set-Cookie: foo2=bar2; Domain=www.zend2.com; Path=/',
+        ];
+
+        $response = Cookies::fromResponse($response, 'http://www.zend.com');
+        $result = $response->getAllCookies(Cookies::COOKIE_STRING_ARRAY);
+        $this->assertSame($expected, $result);
+    }
+
     public function testRequestCanHaveArrayCookies()
     {
         $_COOKIE = [
diff --git a/test/Exception/UnexpectedValueExceptionTest.php b/test/Exception/UnexpectedValueExceptionTest.php
new file mode 100644
index 0000000000..f24daed560
--- /dev/null
+++ b/test/Exception/UnexpectedValueExceptionTest.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace ZendTest\Http\Exception;
+
+use ArrayObject;
+use Zend\Http\Exception\UnexpectedValueException;
+use PHPUnit\Framework\TestCase;
+
+class UnexpectedValueExceptionTest extends TestCase
+{
+    public function testUnexpectedTypeWithObjectType()
+    {
+        $object = new ArrayObject();
+        $exception = UnexpectedValueException::unexpectedType('foo', $object);
+
+        $this->assertSame('Expected foo. ArrayObject given', $exception->getMessage());
+    }
+
+    public function testUnexpectedTypeWithScalarType()
+    {
+        $exception = UnexpectedValueException::unexpectedType('foo', 5);
+
+        $this->assertSame('Expected foo. integer given', $exception->getMessage());
+    }
+}
diff --git a/test/Header/SetCookieTest.php b/test/Header/SetCookieTest.php
index aa35678e9e..ff89f9e761 100644
--- a/test/Header/SetCookieTest.php
+++ b/test/Header/SetCookieTest.php
@@ -146,7 +146,7 @@ public function testSetCookieFromStringCanCreateSingleHeader()
         $this->assertEquals('/accounts', $setCookieHeader->getPath());
         $this->assertEquals('Wed, 13-Jan-2021 22:23:01 GMT', $setCookieHeader->getExpires());
         $this->assertTrue($setCookieHeader->isSecure());
-        $this->assertTrue($setCookieHeader->isHttponly());
+        $this->assertTrue($setCookieHeader->isHttpOnly());
 
         $setCookieHeader = SetCookie::fromString(
             'set-cookie: myname=myvalue; Domain=docs.foo.com; Path=/accounts;'
@@ -310,7 +310,7 @@ public function testSetCookieAttributesAreUnsettable()
         $this->assertNull($setCookieHeader->getDomain());
         $this->assertNull($setCookieHeader->getPath());
         $this->assertNull($setCookieHeader->isSecure());
-        $this->assertNull($setCookieHeader->isHttponly());
+        $this->assertNull($setCookieHeader->isHttpOnly());
     }
 
     public function testSetCookieFieldValueIsEmptyStringWhenNameIsUnset()
diff --git a/test/HeadersTest.php b/test/HeadersTest.php
index d2ac2ba6ce..72e040dcda 100644
--- a/test/HeadersTest.php
+++ b/test/HeadersTest.php
@@ -441,4 +441,10 @@ public function testThrowExceptionOnInvalidHeader()
         $this->expectExceptionMessage('Invalid header value detected');
         $headers->get('Location');
     }
+
+    public function testHeadersFromStringFactoryWithNoCurrentLineShouldThrowException()
+    {
+        $this->expectException(RuntimeException::class);
+        Headers::fromString(" Fake foo\r\n -bar");
+    }
 }
diff --git a/test/ResponseTest.php b/test/ResponseTest.php
index b62aaa15e4..26008eff65 100644
--- a/test/ResponseTest.php
+++ b/test/ResponseTest.php
@@ -16,6 +16,23 @@
 
 class ResponseTest extends TestCase
 {
+
+    private $originalErrorReporting;
+
+    protected function setUp()
+    {
+        $this->originalErrorReporting = \error_reporting();
+
+        parent::setUp();
+    }
+
+    protected function tearDown()
+    {
+        \error_reporting($this->originalErrorReporting);
+
+        parent::tearDown();
+    }
+
     public function validHttpVersions()
     {
         yield 'http/1.0' => ['1.0'];
@@ -226,6 +243,35 @@ public function testDeflateResponse()
         $this->assertEquals('ad62c21c3aa77b6a6f39600f6dd553b8', md5($res->getContent()));
     }
 
+    public function testDeflateResponseWithDeflateError()
+    {
+        \error_reporting(E_ALL ^ \E_STRICT ^ \E_WARNING);
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('An error occurred during inflation');
+
+        $responseTest = <<<'REQ'
+HTTP/1.1 200 OK
+Date: Sun, 25 Jun 2006 19:38:02 GMT
+Server: Apache
+X-powered-by: PHP/5.1.4-pl3-gentoo
+Content-encoding: deflate
+Vary: Accept-Encoding
+Content-length: 300
+Connection: close
+Content-type: text/html
+
+REQ;
+
+        // uncompressed data is more than 32768 times the length of the compressed input data
+        $data = \str_repeat('1', 10000000);
+
+        $responseTest .= "\n" . \gzdeflate($data);
+
+        $res = Response::fromString($responseTest);
+        $res->getBody();
+    }
+
     public function testDeflateResponseWithEmptyBody()
     {
         $responseTest = <<<'REQ'
@@ -632,6 +678,14 @@ public function test100ContinueFromString()
         $this->assertEquals($fixture, $request->getBody());
     }
 
+    public function test100ContinueWithInvalidContent()
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Invalid response content');
+
+        Response::fromString("HTTP/1.1 100 Continue\r\n");
+    }
+
     /**
      * Helper function: read test response from file
      *