[5.x] Allow adding of GraphQL mutations

config/graphql.php

@@ -42,6 +42,20 @@
         //
     ],
 
+    /*
+    |--------------------------------------------------------------------------
+    | Mutations
+    |--------------------------------------------------------------------------
+    |
+    | Here you may list mutations to be added to the Statamic schema.
+    |
+    | https://statamic.dev/graphql#custom-mutations
+    */
+
+    'mutations' => [
+        //
+    ],
+
     /*
     |--------------------------------------------------------------------------
     | Middleware

src/GraphQL/DefaultSchema.php

@@ -45,7 +45,7 @@ public function getConfig()
     {
         return [
             'query' => $this->getQueries(),
-            'mutation' => [],
+            'mutation' => $this->getMutations(),
             'middleware' => $this->getMiddleware(),
             'method' => ['GET', 'POST'],
         ];
@@ -82,4 +82,9 @@ private function getMiddleware()
             GraphQL::getExtraMiddleware()
         );
     }
+
+    private function getMutations()
+    {
+        return config('statamic.graphql.mutations', []);
+    }
 }

src/GraphQL/Middleware/CacheResponse.php

@@ -13,6 +13,10 @@ public function handle($request, Closure $next)
             return $next($request);
         }
 
+        if ($this->isMutation($request)) {
+            return $next($request);
+        }
+
         $cache = app(ResponseCache::class);
 
         if ($response = $cache->get($request)) {
@@ -25,4 +29,11 @@ public function handle($request, Closure $next)
 
         return $response;
     }
+
+    protected function isMutation($request): bool
+    {
+        $query = ltrim(strtolower($request->get('query', '')));
+
+        return str_starts_with($query, 'mutation');
+    }
 }

tests/Feature/GraphQL/CustomMutationTest.php

@@ -0,0 +1,142 @@
+<?php
+
+namespace Tests\Feature\GraphQL;
+
+use GraphQL\Type\Definition\Type;
+use Orchestra\Testbench\Attributes\DefineEnvironment;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\Test;
+use Rebing\GraphQL\Support\Mutation;
+use Statamic\Facades\GraphQL;
+use Tests\TestCase;
+
+#[Group('graphql')]
+class CustomMutationTest extends TestCase
+{
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        app()->instance('mutation-count', 0);
+    }
+
+    #[Test]
+    public function custom_mutation_does_not_yet_exist()
+    {
+        $this
+            ->post('/graphql', ['query' => 'mutation { createItem(name: "test") }'])
+            ->assertJson(['errors' => [[
+                'message' => 'Schema is not configured for mutations.',
+            ]]]);
+    }
+
+    #[Test]
+    #[DefineEnvironment('addCustomMutationsThroughConfig')]
+    public function a_custom_mutation_can_be_added_to_the_default_schema_through_config()
+    {
+        $this
+            ->post('/graphql', ['query' => 'mutation { createItem(name: "test") }'])
+            ->assertGqlOk()
+            ->assertExactJson(['data' => ['createItem' => 'Item created: test']]);
+    }
+
+    #[Test]
+    #[DefineEnvironment('addCustomMutationsThroughConfig')]
+    public function multiple_custom_mutations_can_be_added()
+    {
+        $this
+            ->post('/graphql', ['query' => 'mutation { createItem(name: "first") }'])
+            ->assertGqlOk()
+            ->assertExactJson(['data' => ['createItem' => 'Item created: first']]);
+
+        $this
+            ->post('/graphql', ['query' => 'mutation { updateItem(id: 1, name: "updated") }'])
+            ->assertGqlOk()
+            ->assertExactJson(['data' => ['updateItem' => 'Item 1 updated: updated']]);
+    }
+
+    #[Test]
+    #[DefineEnvironment('addCustomMutationsThroughConfig')]
+    public function mutations_are_not_cached()
+    {
+        $this
+            ->post('/graphql', ['query' => 'mutation { createItem(name: "test") }'])
+            ->assertGqlOk()
+            ->assertExactJson(['data' => ['createItem' => 'Item created: test']]);
+
+        $this
+            ->post('/graphql', ['query' => 'mutation { createItem(name: "test") }'])
+            ->assertGqlOk()
+            ->assertExactJson(['data' => ['createItem' => 'Item created: test']]);
+
+        $this->assertEquals(2, app('mutation-count'));
+    }
+
+    protected function addCustomMutationsThroughConfig($app)
+    {
+        $app['config']->set('statamic.graphql.mutations', [
+            CreateItemMutation::class,
+            UpdateItemMutation::class,
+        ]);
+    }
+}
+
+class CreateItemMutation extends Mutation
+{
+    protected $attributes = [
+        'name' => 'createItem',
+    ];
+
+    public function type(): Type
+    {
+        return GraphQL::string();
+    }
+
+    public function args(): array
+    {
+        return [
+            'name' => [
+                'type' => Type::nonNull(Type::string()),
+                'description' => 'The name of the item to create',
+            ],
+        ];
+    }
+
+    public function resolve($root, $args)
+    {
+        app()->instance('mutation-count', app('mutation-count') + 1);
+
+        return 'Item created: '.$args['name'];
+    }
+}
+
+class UpdateItemMutation extends Mutation
+{
+    protected $attributes = [
+        'name' => 'updateItem',
+    ];
+
+    public function type(): Type
+    {
+        return GraphQL::string();
+    }
+
+    public function args(): array
+    {
+        return [
+            'id' => [
+                'type' => Type::nonNull(Type::int()),
+                'description' => 'The ID of the item to update',
+            ],
+            'name' => [
+                'type' => Type::nonNull(Type::string()),
+                'description' => 'The new name of the item',
+            ],
+        ];
+    }
+
+    public function resolve($root, $args)
+    {
+        return "Item {$args['id']} updated: {$args['name']}";
+    }
+}