Make clientMutationId optional

Author: ivome

src/Mutation/Mutation.php

@@ -49,7 +49,7 @@ public static function mutationWithClientMutationId(array $config)
             $inputFieldsResolved = self::resolveMaybeThunk($inputFields);
             return array_merge($inputFieldsResolved !== null ? $inputFieldsResolved : [], [
                 'clientMutationId' => [
-                    'type' => Type::nonNull(Type::string())
+                    'type' => Type::string()
                 ]
             ]);
         };
@@ -58,7 +58,7 @@ public static function mutationWithClientMutationId(array $config)
             $outputFieldsResolved = self::resolveMaybeThunk($outputFields);
             return array_merge($outputFieldsResolved !== null ? $outputFieldsResolved : [], [
                 'clientMutationId' => [
-                    'type' => Type::nonNull(Type::string())
+                    'type' => Type::string()
                 ]
             ]);
         };

tests/Mutation/MutationTest.php

@@ -204,12 +204,9 @@ public function testIntrospection()
                     [
                         'name' => 'clientMutationId',
                         'type' => [
-                            'name' => null,
-                            'kind' => 'NON_NULL',
-                            'ofType' => [
-                                'name' => 'String',
-                                'kind' => 'SCALAR'
-                            ]
+                            'name' => 'String',
+                            'kind' => 'SCALAR',
+                            'ofType' => null
                         ]
                     ]
                 ]
@@ -254,12 +251,9 @@ public function testContainsCorrectPayload() {
                     [
                         'name' => 'clientMutationId',
                         'type' => [
-                            'name' => null,
-                            'kind' => 'NON_NULL',
-                            'ofType' => [
-                                'name' => 'String',
-                                'kind' => 'SCALAR'
-                            ]
+                            'name' => 'String',
+                            'kind' => 'SCALAR',
+                            'ofType' => null
                         ]
                     ]
                 ]