Add support for guzzle promises in props (#316)

Co-authored-by: Rhys <[email protected]>
Co-authored-by: Claudio Dekker <[email protected]>

Author: rhysemmerson

src/Response.php

@@ -3,6 +3,7 @@
 namespace Inertia;
 
 use Closure;
+use GuzzleHttp\Promise\PromiseInterface;
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Contracts\Support\Responsable;
 use Illuminate\Http\JsonResponse;
@@ -101,6 +102,10 @@ public function toResponse($request)
                 $prop = App::call($prop);
             }
 
+            if ($prop instanceof PromiseInterface) {
+                $prop = $prop->wait();
+            }
+
             if ($prop instanceof ResourceResponse || $prop instanceof JsonResource) {
                 $prop = $prop->toResponse($request)->getData(true);
             }

tests/ResponseTest.php

@@ -14,6 +14,7 @@
 use Inertia\LazyProp;
 use Inertia\Response;
 use Inertia\Tests\Stubs\FakeResource;
+use Mockery;
 
 class ResponseTest extends TestCase
 {
@@ -153,6 +154,29 @@ public function test_arrayable_prop_response(): void
         $this->assertSame('123', $page->version);
     }
 
+    public function test_promise_props_are_resolved(): void
+    {
+        $request = Request::create('/user/123', 'GET');
+        $request->headers->add(['X-Inertia' => 'true']);
+
+        $user = (object) ['name' => 'Jonathan'];
+
+        $promise = Mockery::mock('GuzzleHttp\Promise\PromiseInterface')
+            ->shouldReceive('wait')
+            ->andReturn($user)
+            ->mock();
+
+        $response = new Response('User/Edit', ['user' => $promise], 'app', '123');
+        $response = $response->toResponse($request);
+        $page = $response->getData();
+
+        $this->assertInstanceOf(JsonResponse::class, $response);
+        $this->assertSame('User/Edit', $page->component);
+        $this->assertSame('Jonathan', $page->props->user->name);
+        $this->assertSame('/user/123', $page->url);
+        $this->assertSame('123', $page->version);
+    }
+
     public function test_xhr_partial_response(): void
     {
         $request = Request::create('/user/123', 'GET');