diff --git a/tests/Executor/ListsTest.php b/tests/Executor/ListsTest.php
index 1cad0e8..dbcffa5 100644
--- a/tests/Executor/ListsTest.php
+++ b/tests/Executor/ListsTest.php
@@ -1,9 +1,11 @@
 <?php
+
 namespace GraphQL\Tests\Executor;
 
-use GraphQL\Error\Error;
+use GraphQL\Executor\ExecutionResult;
 use GraphQL\Executor\Executor;
 use GraphQL\Error\FormattedError;
+use GraphQL\Executor\Promise\Adapter\ReactPromiseAdapter;
 use GraphQL\Language\Parser;
 use GraphQL\Language\SourceLocation;
 use GraphQL\Schema;
@@ -12,6 +14,521 @@ use GraphQL\Type\Definition\Type;
 
 class ListsTest extends \PHPUnit_Framework_TestCase
 {
+    public static function setUpBeforeClass()
+    {
+        Executor::setPromiseAdapter(new ReactPromiseAdapter());
+    }
+
+    public static function tearDownAfterClass()
+    {
+        Executor::setPromiseAdapter(null);
+    }
+
+    // Describe: Execute: Handles list nullability
+
+    /**
+     * @describe [T]
+     */
+    public function testHandlesNullableListsWithArray()
+    {
+        // Contains values
+        $this->checkHandlesNullableLists(
+            [ 1, 2 ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNullableLists(
+            [ 1, null, 2 ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
+        );
+
+        // Returns null
+        $this->checkHandlesNullableLists(
+            null,
+            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
+        );
+    }
+
+    /**
+     * @describe [T]
+     */
+    public function testHandlesNullableListsWithPromiseArray()
+    {
+        // Contains values
+        $this->checkHandlesNullableLists(
+            \React\Promise\resolve([ 1, 2 ]),
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNullableLists(
+            \React\Promise\resolve([ 1, null, 2 ]),
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
+        );
+
+        // Returns null
+        $this->checkHandlesNullableLists(
+            \React\Promise\resolve(null),
+            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
+        );
+
+        // Rejected
+        $this->checkHandlesNullableLists(
+            function () {
+                return \React\Promise\reject(new \Exception('bad'));
+            },
+            [
+                'data' => ['nest' => ['test' => null]],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test']
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T]
+     */
+    public function testHandlesNullableListsWithArrayPromise()
+    {
+        // Contains values
+        $this->checkHandlesNullableLists(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNullableLists(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(null), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
+        );
+
+        // Returns null
+        $this->checkHandlesNullableLists(
+            \React\Promise\resolve(null),
+            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
+        );
+
+        // Contains reject
+        $this->checkHandlesNullableLists(
+            function () {
+                return [ \React\Promise\resolve(1), \React\Promise\reject(new \Exception('bad')), \React\Promise\resolve(2) ];
+            },
+            [
+                'data' => ['nest' => ['test' => [1, null, 2]]],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test', 1]
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T]!
+     */
+    public function testHandlesNonNullableListsWithArray()
+    {
+        // Contains values
+        $this->checkHandlesNonNullableLists(
+            [ 1, 2 ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNonNullableLists(
+            [ 1, null, 2 ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
+        );
+
+        // Returns null
+        $this->checkHandlesNonNullableLists(
+            null,
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T]!
+     */
+    public function testHandlesNonNullableListsWithPromiseArray()
+    {
+        // Contains values
+        $this->checkHandlesNonNullableLists(
+            \React\Promise\resolve([ 1, 2 ]),
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNonNullableLists(
+            \React\Promise\resolve([ 1, null, 2 ]),
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
+        );
+
+        // Returns null
+        $this->checkHandlesNonNullableLists(
+            null,
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Rejected
+        $this->checkHandlesNonNullableLists(
+            function () {
+                return \React\Promise\reject(new \Exception('bad'));
+            },
+            [
+                'data' => ['nest' => null],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test']
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T]!
+     */
+    public function testHandlesNonNullableListsWithArrayPromise()
+    {
+        // Contains values
+        $this->checkHandlesNonNullableLists(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNonNullableLists(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(null), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
+        );
+
+        // Contains reject
+        $this->checkHandlesNonNullableLists(
+            function () {
+                return [ \React\Promise\resolve(1), \React\Promise\reject(new \Exception('bad')), \React\Promise\resolve(2) ];
+            },
+            [
+                'data' => ['nest' => ['test' => [1, null, 2]]],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test', 1]
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T!]
+     */
+    public function testHandlesListOfNonNullsWithArray()
+    {
+        // Contains values
+        $this->checkHandlesListOfNonNulls(
+            [ 1, 2 ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesListOfNonNulls(
+            [ 1, null, 2 ],
+            [
+                'data' => [ 'nest' => [ 'test' => null ] ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Returns null
+        $this->checkHandlesListOfNonNulls(
+            null,
+            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
+        );
+    }
+
+    /**
+     * @describe [T!]
+     */
+    public function testHandlesListOfNonNullsWithPromiseArray()
+    {
+        // Contains values
+        $this->checkHandlesListOfNonNulls(
+            \React\Promise\resolve([ 1, 2 ]),
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesListOfNonNulls(
+            \React\Promise\resolve([ 1, null, 2 ]),
+            [
+                'data' => [ 'nest' => [ 'test' => null ] ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Returns null
+        $this->checkHandlesListOfNonNulls(
+            \React\Promise\resolve(null),
+            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
+        );
+
+        // Rejected
+        $this->checkHandlesListOfNonNulls(
+            function () {
+                return \React\Promise\reject(new \Exception('bad'));
+            },
+            [
+                'data' => ['nest' => ['test' => null]],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test']
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T]!
+     */
+    public function testHandlesListOfNonNullsWithArrayPromise()
+    {
+        // Contains values
+        $this->checkHandlesListOfNonNulls(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesListOfNonNulls(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(null), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
+        );
+
+        // Contains reject
+        $this->checkHandlesListOfNonNulls(
+            function () {
+                return [ \React\Promise\resolve(1), \React\Promise\reject(new \Exception('bad')), \React\Promise\resolve(2) ];
+            },
+            [
+                'data' => ['nest' => ['test' => null]],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test', 1]
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T!]!
+     */
+    public function testHandlesNonNullListOfNonNullsWithArray()
+    {
+        // Contains values
+        $this->checkHandlesNonNullListOfNonNulls(
+            [ 1, 2 ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+
+        // Contains null
+        $this->checkHandlesNonNullListOfNonNulls(
+            [ 1, null, 2 ],
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Returns null
+        $this->checkHandlesNonNullListOfNonNulls(
+            null,
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T!]!
+     */
+    public function testHandlesNonNullListOfNonNullsWithPromiseArray()
+    {
+        // Contains values
+        $this->checkHandlesNonNullListOfNonNulls(
+            \React\Promise\resolve([ 1, 2 ]),
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNonNullListOfNonNulls(
+            \React\Promise\resolve([ 1, null, 2 ]),
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Returns null
+        $this->checkHandlesNonNullListOfNonNulls(
+            \React\Promise\resolve(null),
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Rejected
+        $this->checkHandlesNonNullListOfNonNulls(
+            function () {
+                return \React\Promise\reject(new \Exception('bad'));
+            },
+            [
+                'data' => ['nest' => null ],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test']
+                    ]
+                ]
+            ]
+        );
+    }
+
+    /**
+     * @describe [T!]!
+     */
+    public function testHandlesNonNullListOfNonNullsWithArrayPromise()
+    {
+        // Contains values
+        $this->checkHandlesNonNullListOfNonNulls(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(2) ],
+            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
+        );
+
+        // Contains null
+        $this->checkHandlesNonNullListOfNonNulls(
+            [ \React\Promise\resolve(1), \React\Promise\resolve(null), \React\Promise\resolve(2) ],
+            [
+                'data' => [ 'nest' => null ],
+                'errors' => [
+                    FormattedError::create(
+                        'Cannot return null for non-nullable field DataType.test.',
+                        [ new SourceLocation(1, 10) ]
+                    )
+                ]
+            ]
+        );
+
+        // Contains reject
+        $this->checkHandlesNonNullListOfNonNulls(
+            function () {
+                return [ \React\Promise\resolve(1), \React\Promise\reject(new \Exception('bad')), \React\Promise\resolve(2) ];
+            },
+            [
+                'data' => ['nest' => null ],
+                'errors' => [
+                    [
+                        'message' => 'bad',
+                        'locations' => [['line' => 1, 'column' => 10]],
+                        'path' => ['nest', 'test']
+                    ]
+                ]
+            ]
+        );
+    }
+
+    private function checkHandlesNullableLists($testData, $expected)
+    {
+        $testType = Type::listOf(Type::int());;
+        $this->check($testType, $testData, $expected);
+    }
+
+    private function checkHandlesNonNullableLists($testData, $expected)
+    {
+        $testType = Type::nonNull(Type::listOf(Type::int()));
+        $this->check($testType, $testData, $expected);
+    }
+
+    private function checkHandlesListOfNonNulls($testData, $expected)
+    {
+        $testType = Type::listOf(Type::nonNull(Type::int()));
+        $this->check($testType, $testData, $expected);
+    }
+
+    public function checkHandlesNonNullListOfNonNulls($testData, $expected)
+    {
+        $testType = Type::nonNull(Type::listOf(Type::nonNull(Type::int())));
+        $this->check($testType, $testData, $expected);
+    }
+
     private function check($testType, $testData, $expected)
     {
         $data = ['test' => $testData];
@@ -41,157 +558,19 @@ class ListsTest extends \PHPUnit_Framework_TestCase
         $ast = Parser::parse('{ nest { test } }');
 
         $result = Executor::execute($schema, $ast, $data);
-        $this->assertArraySubset($expected, $result->toArray());
-    }
-
-    // Describe: Execute: Handles list nullability
-
-    /**
-     * @describe [T]
-     */
-    public function testHandlesNullableLists()
-    {
-        $type = Type::listOf(Type::int());
-
-        // Contains values
-        $this->check(
-            $type,
-            [ 1, 2 ],
-            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
-        );
-
-        // Contains null
-        $this->check(
-            $type,
-            [ 1, null, 2 ],
-            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
-        );
-
-        // Returns null
-        $this->check(
-            $type,
-            null,
-            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
-        );
+        $this->assertArraySubset($expected, self::awaitPromise($result));
     }
 
     /**
-     * @describe [T]!
+     * @param \GraphQL\Executor\Promise\Promise $promise
+     * @return array
      */
-    public function testHandlesNonNullableLists()
+    private static function awaitPromise($promise)
     {
-        $type = Type::nonNull(Type::listOf(Type::int()));
-
-        // Contains values
-        $this->check(
-            $type,
-            [ 1, 2 ],
-            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
-        );
-
-        // Contains null
-        $this->check(
-            $type,
-            [ 1, null, 2 ],
-            [ 'data' => [ 'nest' => [ 'test' => [ 1, null, 2 ] ] ] ]
-        );
-
-        // Returns null
-        $this->check(
-            $type,
-            null,
-            [
-                'data' => [ 'nest' => null ],
-                'errors' => [
-                    FormattedError::create(
-                        'Cannot return null for non-nullable field DataType.test.',
-                        [ new SourceLocation(1, 10) ]
-                    )
-                ]
-            ]
-        );
-    }
-
-    /**
-     * @describe [T!]
-     */
-    public function testHandlesListOfNonNulls()
-    {
-        $type = Type::listOf(Type::nonNull(Type::int()));
-
-        // Contains values
-        $this->check(
-            $type,
-            [ 1, 2 ],
-            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
-        );
-
-        // Contains null
-        $this->check(
-            $type,
-            [ 1, null, 2 ],
-            [
-                'data' => [ 'nest' => [ 'test' => null ] ],
-                'errors' => [
-                    FormattedError::create(
-                        'Cannot return null for non-nullable field DataType.test.',
-                        [ new SourceLocation(1, 10) ]
-                    )
-                ]
-            ]
-        );
-
-        // Returns null
-        $this->check(
-            $type,
-            null,
-            [ 'data' => [ 'nest' => [ 'test' => null ] ] ]
-        );
-    }
-
-    /**
-     * @describe [T!]!
-     */
-    public function testHandlesNonNullListOfNonNulls()
-    {
-        $type = Type::nonNull(Type::listOf(Type::nonNull(Type::int())));
-
-        // Contains values
-        $this->check(
-            $type,
-            [ 1, 2 ],
-            [ 'data' => [ 'nest' => [ 'test' => [ 1, 2 ] ] ] ]
-        );
-
-
-        // Contains null
-        $this->check(
-            $type,
-            [ 1, null, 2 ],
-            [
-                'data' => [ 'nest' => null ],
-                'errors' => [
-                    FormattedError::create(
-                        'Cannot return null for non-nullable field DataType.test.',
-                        [ new SourceLocation(1, 10) ]
-                    )
-                ]
-            ]
-        );
-
-        // Returns null
-        $this->check(
-            $type,
-            null,
-            [
-                'data' => [ 'nest' => null ],
-                'errors' => [
-                    FormattedError::create(
-                        'Cannot return null for non-nullable field DataType.test.',
-                        [ new SourceLocation(1, 10) ]
-                    )
-                ]
-            ]
-        );
+        $results = null;
+        $promise->then(function (ExecutionResult $executionResult) use (&$results) {
+            $results = $executionResult->toArray();
+        });
+        return $results;
     }
 }