Fix for #618 DateTime is not set to UTC when using Extract (#619)

* Test for issue 618 - DateTime not set to UTC

* Fix issue 618 - DateTime not set to UTC

src/QueryType/Extract/RequestBuilder.php

@@ -48,6 +48,9 @@ class RequestBuilder extends BaseRequestBuilder
 
             // literal.*
             foreach ($doc->getFields() as $name => $value) {
+                if ($value instanceof \DateTime) {
+                    $value = $query->getHelper()->formatDate($value);
+                }
                 $value = (array) $value;
                 foreach ($value as $multival) {
                     $request->addParam('literal.'.$name, $multival);

tests/QueryType/Extract/RequestBuilderTest.php

@@ -113,4 +113,29 @@ class RequestBuilderTest extends TestCase
 
         $this->assertSame($headers, $request->getHeaders());
     }
+
+    public function testDocumentDateTimeField()
+    {
+        $timezone = new \DateTimeZone('Europe/London');
+        $date = new \DateTime('2013-01-15 14:41:58', $timezone);
+
+        $document = $this->query->createDocument(['date' => $date]);
+        $this->query->setDocument($document);
+
+        $request = $this->builder->build($this->query);
+
+        $this->assertEquals(
+            [
+                'fmap.from-field' => 'to-field',
+                'literal.date' => '2013-01-15T14:41:58Z',
+                'omitHeader' => 'true',
+                'extractOnly' => 'false',
+                'param1' => 'value1',
+                'resource.name' => 'RequestBuilderTest.php',
+                'wt' => 'json',
+                'json.nl' => 'flat',
+            ],
+            $request->getParams()
+        );
+    }
 }