MC-36456: union implementation

Author: cpartica

dev/tests/api-functional/_files/Magento/TestModuleGraphQlQuery/Model/Resolver/Item.php

@@ -11,6 +11,9 @@
 use Magento\Framework\GraphQl\Config\Element\Field;
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 
+/**
+ * Resolver for Item
+ */
 class Item implements ResolverInterface
 {
     /**

dev/tests/api-functional/_files/Magento/TestModuleGraphQlQuery/Model/Resolver/UnionType1.php

@@ -0,0 +1,49 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestModuleGraphQlQuery\Model\Resolver;
+
+use Magento\Framework\GraphQl\Config\Element\Field;
+use Magento\Framework\GraphQl\Query\ResolverInterface;
+use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Sales\Model\ResourceModel\Order\CollectionFactoryInterface;
+
+/**
+ * Resolver for Union Type 1
+ */
+class UnionType1 implements ResolverInterface
+{
+    /**
+     * @var CollectionFactoryInterface
+     */
+    private $collectionFactory;
+
+    /**
+     * @param CollectionFactoryInterface $collectionFactory
+     */
+    public function __construct(
+        CollectionFactoryInterface $collectionFactory
+    ) {
+        $this->collectionFactory = $collectionFactory;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function resolve(
+        Field $field,
+        $context,
+        ResolveInfo $info,
+        array $value = null,
+        array $args = null
+    ) {
+        return [
+            'custom_name1' => 'custom_name1_value',
+            'custom_name2' => 'custom_name2_value',
+        ];
+    }
+}

dev/tests/api-functional/_files/Magento/TestModuleGraphQlQuery/Model/Resolver/UnionTypeResolver.php

@@ -0,0 +1,28 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\TestModuleGraphQlQuery\Model\Resolver;
+
+use Magento\Framework\GraphQl\Query\Resolver\TypeResolverInterface;
+
+/**
+ * Type Resolver for union
+ */
+class UnionTypeResolver implements TypeResolverInterface
+{
+    /**
+     * @inheritDoc
+     */
+    public function resolveType(array $data): string
+    {
+        if (!empty($data)) {
+            return 'TypeCustom1';
+        }
+        return '';
+    }
+
+}

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

@@ -3,6 +3,7 @@
 
 type Query {
     testItem(id: Int!) : Item @resolver(class: "Magento\\TestModuleGraphQlQuery\\Model\\Resolver\\Item")
+    testUnion: UnionType1 @resolver(class: "Magento\\TestModuleGraphQlQuery\\Model\\Resolver\\UnionType1")
 }
 
 type Mutation {
@@ -18,3 +19,14 @@ type MutationItem {
     item_id: Int
     name: String
 }
+
+union UnionType1 @doc(description: "some kind of union") @typeResolver(class: "Magento\\TestModuleGraphQlQuery\\Model\\Resolver\\UnionTypeResolver")  =
+    TypeCustom1 | TypeCustom2
+
+type TypeCustom1 {
+    custom_name1: String
+}
+
+type TypeCustom2 {
+    custom_name2: String
+}

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

@@ -25,6 +25,15 @@ public function testQueryTestModuleReturnsResults()
         item_id
         name
     }
+    testUnion {
+      __typename
+      ... on TypeCustom1 {
+          custom_name1
+      }
+      ... on TypeCustom2 {
+          custom_name2
+      }
+    }
 }
 QUERY;
 
@@ -100,4 +109,42 @@ public function testQueryViaGetRequestWithVariablesReturnsResults()
 
         $this->assertArrayHasKey('testItem', $response);
     }
+
+    public function testQueryTestUnionResults()
+    {
+        $id = 1;
+
+        $query = <<<QUERY
+{
+    testItem(id: {$id})
+    {
+        item_id
+        name
+    }
+    testUnion {
+      __typename
+      ... on TypeCustom1 {
+          custom_name1
+      }
+      ... on TypeCustom2 {
+          custom_name2
+      }
+    }
+}
+QUERY;
+
+        $response = $this->graphQlQuery($query);
+        $this->assertArrayHasKey('testItem', $response);
+        $testItem = $response['testItem'];
+        $this->assertArrayHasKey('item_id', $testItem);
+        $this->assertArrayHasKey('name', $testItem);
+        $this->assertEquals(1, $testItem['item_id']);
+        $this->assertEquals('itemName', $testItem['name']);
+
+        $this->assertArrayHasKey('testUnion', $response);
+        $testUnion = $response['testUnion'];
+        $this->assertArrayHasKey('custom_name1', $testUnion);
+        $this->assertEquals('custom_name1_value', $testUnion['custom_name1']);
+        $this->assertArrayNotHasKey('custom_name2', $testUnion);
+    }
 }