Forward compatibility with upcoming Promise v3

composer.json

@@ -14,8 +14,8 @@
         "php": ">=7.1",
         "nikic/fast-route": "^1.3",
         "react/async": "^4 || ^3",
-        "react/http": "^1.7",
-        "react/promise": "^2.7"
+        "react/http": "^1.8",
+        "react/promise": "^3 || ^2.7"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5 || ^7.5",

src/ErrorHandler.php

@@ -48,10 +48,13 @@ public function __invoke(ServerRequestInterface $request, callable $next)
                     return $this->errorInvalidResponse($response);
                 }
             }, function ($e) {
+                // Promise rejected, always a `\Throwable` as of Promise v3
+                assert($e instanceof \Throwable || !\method_exists(PromiseInterface::class, 'catch'));
+
                 if ($e instanceof \Throwable) {
                     return $this->errorInvalidException($e);
                 } else {
-                    return $this->errorInvalidResponse(\React\Promise\reject($e));
+                    return $this->errorInvalidResponse(\React\Promise\reject($e)); // @codeCoverageIgnore
                 }
             });
         } elseif ($response instanceof \Generator) {

tests/AppTest.php

@@ -1534,6 +1534,10 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
 
     public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWithInternalServerErrorResponseWhenHandlerReturnsPromiseWhichRejectsWithNull()
     {
+        if (method_exists(PromiseInterface::class, 'catch')) {
+            $this->markTestSkipped('Only supported for legacy Promise v2, Promise v3 always rejects with Throwable');
+        }
+
         $app = $this->createAppWithoutLogger();
 
         $app->get('/users', function () {

tests/ErrorHandlerTest.php

@@ -273,6 +273,10 @@ public function testInvokeWithHandlerReturningPromiseResolvingWithNullReturnsPro
 
     public function testInvokeWithHandlerReturningPromiseRejectingWithNullReturnsPromiseResolvingWithError500Response()
     {
+        if (method_exists(PromiseInterface::class, 'catch')) {
+            $this->markTestSkipped('Only supported for legacy Promise v2, Promise v3 always rejects with Throwable');
+        }
+
         $handler = new ErrorHandler();
 
         $request = new ServerRequest('GET', 'http://example.com/');