Solarium\Core\Query\Helper::formatDate() now accepts DateTimeInterface / DateTimeImmutable objects

composer.json

@@ -12,7 +12,7 @@
         }
     ],
     "require": {
-        "php": ">=5.3.2",
+        "php": ">=5.6",
         "symfony/event-dispatcher": "~2.3|~3.0"
     },
     "require-dev": {

library/Solarium/Core/Query/Helper.php

@@ -139,7 +139,7 @@ class Helper
      *
      * @see http://lucene.apache.org/solr/api/org/apache/solr/schema/DateField.html
      *
-     * @param int|string|\DateTime $input accepted formats: timestamp, date string or DateTime
+     * @param int|string|\DateTimeInterface $input accepted formats: timestamp, date string or DateTime / DateTimeImmutable
      *
      * @return string|boolean false is returned in case of invalid input
      */
@@ -148,7 +148,7 @@ class Helper
         switch (true) {
 
             // input of datetime object
-            case $input instanceof \DateTime:
+            case $input instanceof \DateTimeInterface:
                 // no work needed
                 break;
 
@@ -180,7 +180,7 @@ class Helper
         // handle the filtered input
         if ($input) {
             // when we get here the input is always a datetime object
-            $input->setTimezone(new \DateTimeZone('UTC'));
+            $input = $input->setTimezone(new \DateTimeZone('UTC'));
             $iso8601 = $input->format(\DateTime::ISO8601);
             $iso8601 = strstr($iso8601, '+', true); //strip timezone
             $iso8601 .= 'Z';

tests/Solarium/Tests/Core/Query/HelperTest.php

@@ -321,6 +321,22 @@ class HelperTest extends \PHPUnit_Framework_TestCase
         );
     }
 
+    public function testFormatDateInputDateTimeImmutable()
+    {
+        date_default_timezone_set("UTC"); // prevent timezone differences
+
+        $this->assertFalse(
+            $this->helper->formatDate(new \stdClass()),
+            'Expect any other object not to be accepted'
+        );
+
+        $this->assertEquals(
+            $this->mockFormatDateOutput(strtotime('2011-10-01')),
+            $this->helper->formatDate(new \DateTimeImmutable('2011-10-01')),
+            'Expects formatDate with DateTimeImmutable input to output ISO8601 with stripped timezone'
+        );
+    }
+
     public function testFormatDate()
     {
         //check if timezone is stripped