GQL-47: Tweaked Client behavior when constructing variables map

- Modified the client to send an empty JSON object in the request instead of an empty array if variables is not defined
- Added test cases to capture the changes

Author: mghoneimy

src/Client.php

@@ -79,6 +79,8 @@ public function runRawQuery(string $queryString, $resultsAsArray = false, array
         }
         $options['headers']['Content-Type'] = 'application/json';
 
+        // Convert empty variables array to empty json object
+        if (empty($variables)) $variables = (object) null;
         // Set query in the request body
         $bodyArray       = ['query' => (string) $queryString, 'variables' => $variables];
         $options['body'] = json_encode($bodyArray);

tests/ClientTest.php

@@ -55,6 +55,7 @@ public function testConstructClient()
         $history     = Middleware::history($container);
         $handler->push($history);
 
+        $mockHandler->append(new Response(200));
         $mockHandler->append(new Response(200));
         $mockHandler->append(new Response(200));
 
@@ -64,17 +65,24 @@ public function testConstructClient()
         $client = new MockClient('', $handler, ['Authorization' => 'Basic xyz']);
         $client->runRawQuery('query_string');
 
+        $client = new MockClient('', $handler);
+        $client->runRawQuery('query_string',  false, ['name' => 'val']);
+
         /** @var Request $firstRequest */
         $firstRequest = $container[0]['request'];
-        $this->assertEquals('{"query":"query_string","variables":[]}', $firstRequest->getBody()->getContents());
+        $this->assertEquals('{"query":"query_string","variables":{}}', $firstRequest->getBody()->getContents());
 
-        /** @var Request $secondRequest */
-        $secondRequest = $container[1]['request'];
-        $this->assertNotNull($secondRequest->getHeader('Authorization'));
+        /** @var Request $thirdRequest */
+        $thirdRequest = $container[1]['request'];
+        $this->assertNotNull($thirdRequest->getHeader('Authorization'));
         $this->assertEquals(
             ['Basic xyz'],
-            $secondRequest->getHeader('Authorization')
+            $thirdRequest->getHeader('Authorization')
         );
+
+        /** @var Request $secondRequest */
+        $secondRequest = $container[2]['request'];
+        $this->assertEquals('{"query":"query_string","variables":{"name":"val"}}', $secondRequest->getBody()->getContents());
     }
 
     /**