Use Stream\first() instead of wrapping our own promise around it

Author: WyriHaximus

composer.json

@@ -10,7 +10,7 @@
         "react/stream": "^1.0 || ^0.7.1",
         "react/promise": "^2.3 || ^1.2.1",
         "evenement/evenement": "^3.0 || ^2.0 || ^1.0",
-        "react/promise-stream": "^1.0 || ^0.1.2"
+        "react/promise-stream": "^1.1"
     },
     "autoload": {
         "psr-4": {

src/Middleware/RequestBodyBufferMiddleware.php

@@ -4,7 +4,6 @@
 
 use OverflowException;
 use Psr\Http\Message\ServerRequestInterface;
-use React\Promise\Promise;
 use React\Promise\Stream;
 use React\Stream\ReadableStreamInterface;
 use RingCentral\Psr7\BufferStream;
@@ -53,13 +52,8 @@ public function __invoke(ServerRequestInterface $request, $stack)
             // but ignore the contents and wait for the close event
             // before passing the request on to the next middleware.
             if ($error instanceof OverflowException) {
-                return new Promise(function ($resolve, $reject) use ($stack, $request, $body) {
-                    $body->on('error', function ($error) use ($reject) {
-                        $reject($error);
-                    });
-                    $body->on('close', function () use ($stack, $request, $resolve) {
-                        $resolve($stack($request));
-                    });
+                return Stream\first($body, 'close')->then(function () use ($stack, $request) {
+                    return $stack($request);
                 });
             }