Fix PsrUri to compatibility to Psr7 interface and Guzzle. Fixed #1.

src/AbstractRequest.php

@@ -79,7 +79,7 @@ public function __construct($uri = null, $method = null, $body = 'php://memory',
 
 		if (!$uri instanceof UriInterface)
 		{
-			$uri = new PsrUri($uri);
+			$uri = new PsrUri((string) $uri);
 		}
 
 		foreach ($headers as $name => $value)

src/Transport/AbstractTransport.php

@@ -49,9 +49,9 @@ public function __construct($options = array())
 	public function request(RequestInterface $request)
 	{
 		$uri = $request->getUri()
-			->withPath(null)
-			->withQuery(null)
-			->withFragment(null);
+			->withPath('')
+			->withQuery('')
+			->withFragment('');
 
 		$uri = $uri . $request->getRequestTarget();
 

src/Uri/PsrUri.php

@@ -43,6 +43,24 @@ class PsrUri extends AbstractUri implements PsrUriInterface
 		'sftp'  => 22
 	);
 
+	/**
+	 * Constructor.
+	 * You can pass a URI string to the constructor to initialise a specific URI.
+	 *
+	 * @param   string  $uri  The optional URI string
+	 *
+	 * @since   2.0
+	 */
+	public function __construct($uri = '')
+	{
+		if (!is_string($uri))
+		{
+			throw new \InvalidArgumentException('URI should be a string');
+		}
+
+		parent::__construct($uri);
+	}
+
 	/**
 	 * Retrieve the authority component of the URI.
 	 *
@@ -222,9 +240,9 @@ public function withPort($port)
 	 */
 	public function withPath($path)
 	{
-		if (is_array($path) || (is_object($path) && !is_callable($path, '__toString')))
+		if (!is_string($path))
 		{
-			throw new \InvalidArgumentException('Invalid path type.');
+			throw new \InvalidArgumentException('URI Path should be a string');
 		}
 
 		$path = (string) $path;
@@ -261,9 +279,9 @@ public function withPath($path)
 	 */
 	public function withQuery($query)
 	{
-		if (is_array($query))
+		if (!is_string($query))
 		{
-			$query = UriHelper::buildQuery($query);
+			throw new \InvalidArgumentException('URI query should be a string or array');
 		}
 
 		$query = UriHelper::filterQuery($query);