Make ResultSet iterator current() not return a mixed value

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file based on the
 
 ### Backward Compatibility Breaks
 
+* Made result sets adhere to `\Iterator` interface definition that they implement. Specifically, you need to call `valid()` on the result set before calling `current()`. When using `foreach` this is done by PHP automatically. When `valid` returns false, the return value of `current` is undefined instead of false. 
+  * `\Elastica\ResultSet::next` returns `void` instead of `\Elastica\Result|false`
+  * `\Elastica\Bulk\ResponseSet::current` returns `\Elastica\Bulk\Response` instead of `\Elastica\Bulk\Response|false`
+  * `\Elastica\Multi\ResultSet::current` returns `\Elastica\ResultSet` instead of `\Elastica\ResultSet|false`
+
 ### Bugfixes
 
 ### Added

lib/Elastica/Bulk/ResponseSet.php

@@ -95,13 +95,11 @@ public function hasError()
     }
 
     /**
-     * @return bool|\Elastica\Bulk\Response
+     * @return \Elastica\Bulk\Response
      */
     public function current()
     {
-        return $this->valid()
-            ? $this->_bulkResponses[$this->key()]
-            : false;
+        return $this->_bulkResponses[$this->key()];
     }
 
     /**

lib/Elastica/Multi/ResultSet.php

@@ -2,7 +2,6 @@
 namespace Elastica\Multi;
 
 use Elastica\Response;
-use Elastica\ResultSet as BaseResultSet;
 
 /**
  * Elastica multi search result set
@@ -36,8 +35,8 @@ class ResultSet implements \Iterator, \ArrayAccess, \Countable
     /**
      * Constructs ResultSet object.
      *
-     * @param \Elastica\Response $response
-     * @param BaseResultSet[]
+     * @param \Elastica\Response    $response
+     * @param \Elastica\ResultSet[] $resultSets
      */
     public function __construct(Response $response, $resultSets)
     {
@@ -80,13 +79,11 @@ public function hasError()
     }
 
     /**
-     * @return bool|\Elastica\ResultSet
+     * @return \Elastica\ResultSet
      */
     public function current()
     {
-        return $this->valid()
-            ? $this->_resultSets[$this->key()]
-            : false;
+        return $this->_resultSets[$this->key()];
     }
 
     /**

lib/Elastica/ResultSet.php

@@ -236,15 +236,11 @@ public function countSuggests()
     /**
      * Returns the current object of the set.
      *
-     * @return \Elastica\Result|bool Set object or false if not valid (no more entries)
+     * @return \Elastica\Result Set object
      */
     public function current()
     {
-        if ($this->valid()) {
-            return $this->_results[$this->key()];
-        }
-
-        return false;
+        return $this->_results[$this->key()];
     }
 
     /**
@@ -253,8 +249,6 @@ public function current()
     public function next()
     {
         ++$this->_position;
-
-        return $this->current();
     }
 
     /**
@@ -308,7 +302,7 @@ public function offsetExists($offset)
      *
      * @throws Exception\InvalidException If offset doesn't exist
      *
-     * @return Result|null
+     * @return Result
      */
     public function offsetGet($offset)
     {

test/Elastica/Bulk/ResponseSetTest.php

@@ -106,14 +106,6 @@ public function testIterator()
         }
 
         $this->assertFalse($responseSet->valid());
-        $this->assertNotInstanceOf(Bulk\Response::class, $responseSet->current());
-        $this->assertFalse($responseSet->current());
-
-        $responseSet->next();
-
-        $this->assertFalse($responseSet->valid());
-        $this->assertNotInstanceOf(Bulk\Response::class, $responseSet->current());
-        $this->assertFalse($responseSet->current());
 
         $responseSet->rewind();
 
@@ -126,21 +118,12 @@ public function isOkDataProvider()
     {
         list($responseData, $actions) = $this->_getFixture();
 
-        $return = [];
-        $return[] = [$responseData, $actions, true];
+        yield [$responseData, $actions, true];
         $responseData['items'][2]['index']['ok'] = false;
-        $return[] = [$responseData, $actions, false];
-
-        return $return;
+        yield [$responseData, $actions, false];
     }
 
-    /**
-     * @param array $responseData
-     * @param array $actions
-     *
-     * @return ResponseSet
-     */
-    protected function _createResponseSet(array $responseData, array $actions)
+    protected function _createResponseSet(array $responseData, array $actions): ResponseSet
     {
         $client = $this->createMock(Client::class);
 
@@ -155,10 +138,7 @@ protected function _createResponseSet(array $responseData, array $actions)
         return $bulk->send();
     }
 
-    /**
-     * @return array
-     */
-    protected function _getFixture()
+    protected function _getFixture(): array
     {
         $responseData = [
             'took' => 5,

test/Elastica/QueryTest.php

@@ -119,7 +119,8 @@ public function testSetSort()
         $this->assertEquals(2, $resultSet->count());
 
         $first = $resultSet->current()->getData();
-        $second = $resultSet->next()->getData();
+        $resultSet->next();
+        $second = $resultSet->current()->getData();
 
         $this->assertEquals('guschti', $first['firstname']);
         $this->assertEquals('nicolas', $second['firstname']);
@@ -130,7 +131,8 @@ public function testSetSort()
         $this->assertEquals(2, $resultSet->count());
 
         $first = $resultSet->current()->getData();
-        $second = $resultSet->next()->getData();
+        $resultSet->next();
+        $second = $resultSet->current()->getData();
 
         $this->assertEquals('nicolas', $first['firstname']);
         $this->assertEquals('guschti', $second['firstname']);