Mutations Prototype (POC) #74

- Added mutation support
- Added GraphQL functional test as an example of how to add mutations

app/code/Magento/GraphQl/etc/schema.graphqls

@@ -4,6 +4,9 @@
 type Query {
 }
 
+type Mutation {
+}
+
 input FilterTypeInput @doc(description: "FilterTypeInput specifies which action will be performed in a query ") {
     eq: String @doc(description: "Equals")
     finset: [String] @doc(description: "Find in set. The value can contain a set of comma-separated values")
@@ -30,4 +33,4 @@ type SearchResultPageInfo @doc(description: "SearchResultPageInfo provides navig
 enum SortEnum @doc(description: "This enumeration indicates whether to return results in ascending or descending order") {
     ASC
     DESC
-}
+}

dev/tests/api-functional/_files/Magento/TestModuleGraphQlQuery/etc/schema.graphqls

@@ -5,7 +5,16 @@ type Query {
     testItem(id: Int!) : Item @resolver(class: "Magento\\TestModuleGraphQlQuery\\Model\\Resolver\\Item")
 }
 
+type Mutation {
+    testItem(id: Int!) : MutationItem @resolver(class: "Magento\\TestModuleGraphQlQuery\\Model\\Resolver\\Item")
+}
+
 type Item {
     item_id: Int
     name: String
 }
+
+type MutationItem {
+    item_id: Int
+    name: String
+}

dev/tests/api-functional/_files/Magento/TestModuleGraphQlQueryExtension/etc/schema.graphqls

@@ -4,3 +4,7 @@
 type Item {
     integer_list: [Int] @resolver(class: "Magento\\TestModuleGraphQlQueryExtension\\Model\\Resolver\\IntegerList")
 }
+
+type MutationItem {
+    integer_list: [Int] @resolver(class: "Magento\\TestModuleGraphQlQueryExtension\\Model\\Resolver\\IntegerList")
+}

dev/tests/api-functional/testsuite/Magento/GraphQl/TestModule/GraphQlMutationTest.php

@@ -0,0 +1,37 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\GraphQl\TestModule;
+
+use Magento\TestFramework\TestCase\GraphQlAbstract;
+
+/**
+ * Make sure that it is possible to use GraphQL mutations in Magento
+ */
+class GraphQlMutationTest extends GraphQlAbstract
+{
+    public function testMutation()
+    {
+        $id = 3;
+
+        $query = <<<MUTATION
+mutation {
+  testItem(id: {$id}) {
+    item_id,
+    name,
+    integer_list
+  }
+}
+MUTATION;
+
+        $response = $this->graphQlQuery($query);
+        $this->assertArrayHasKey('testItem', $response);
+        $testItem = $response['testItem'];
+        $this->assertArrayHasKey('integer_list', $testItem);
+        $this->assertEquals([4, 5, 6], $testItem['integer_list']);
+    }
+}

lib/internal/Magento/Framework/GraphQl/Schema/SchemaGenerator.php

@@ -56,6 +56,7 @@ public function generate() : Schema
         $schema = $this->schemaFactory->create(
             [
                 'query' => $this->outputMapper->getOutputType('Query'),
+                'mutation' => $this->outputMapper->getOutputType('Mutation'),
                 'typeLoader' => function ($name) {
                     return $this->outputMapper->getOutputType($name);
                 },