fix(Query): fix undesired sort of query parameter sort

Closes #386

Author: Jens Schulze

src/Core/Request/AbstractApiRequest.php

@@ -53,6 +53,14 @@ public function __construct(JsonEndpoint $endpoint, Context $context = null)
         $this->setEndpoint($endpoint);
     }
 
+    /**
+     * @return int
+     */
+    public function getParamCount()
+    {
+        return count($this->params);
+    }
+
     /**
      * @return string
      * @internal
@@ -142,7 +150,7 @@ function ($param) {
             },
             $params
         );
-        sort($params);
+        ksort($params);
         $params = implode('&', $params);
 
         return $params;

src/Core/Request/Query/OrderedMultiParameter.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * @author @jenschude <jens.schulze@commercetools.de>
+ */
+
+namespace Commercetools\Core\Request\Query;
+
+class OrderedMultiParameter extends Parameter
+{
+    private $position;
+
+    public function __construct($key, $value = null, $position = 0)
+    {
+        $this->position = $position;
+        parent::__construct($key, $value);
+    }
+
+    public function getId()
+    {
+        return sprintf("%s-%010d", $this->key, $this->position);
+    }
+}

src/Core/Request/SortTrait.php

@@ -7,6 +7,7 @@
 namespace Commercetools\Core\Request;
 
 use Commercetools\Core\Request\Query\MultiParameter;
+use Commercetools\Core\Request\Query\OrderedMultiParameter;
 use Commercetools\Core\Request\Query\ParameterInterface;
 
 /**
@@ -20,14 +21,15 @@ trait SortTrait
      */
     abstract public function addParamObject(ParameterInterface $param);
 
+    abstract public function getParamCount();
     /**
      * @param string $sort
      * @return $this
      */
     public function sort($sort)
     {
         if (!is_null($sort)) {
-            $this->addParamObject(new MultiParameter('sort', $sort));
+            $this->addParamObject(new OrderedMultiParameter('sort', $sort, $this->getParamCount()));
         }
 
         return $this;

tests/unit/Request/AbstractQueryRequestTest.php

@@ -84,6 +84,15 @@ public function testSort()
         $this->assertSame('test?sort=test', (string)$httpRequest->getUri());
     }
 
+    public function testMultiSort()
+    {
+        $request = $this->getQueryRequest();
+        $request->sort('def')->sort('abc')->expand('test');
+        $httpRequest = $request->httpRequest();
+
+        $this->assertSame('test?expand=test&sort=def&sort=abc', (string)$httpRequest->getUri());
+    }
+
     public function testLimit()
     {
         $request = $this->getQueryRequest();