Rewrite promise

src/Client.php

@@ -14,7 +14,6 @@
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\StreamInterface;
 use React\EventLoop\LoopInterface;
-use React\Promise\Deferred;
 use React\HttpClient\Client as ReactClient;
 use React\HttpClient\Request as ReactRequest;
 use React\HttpClient\Response as ReactResponse;
@@ -93,45 +92,42 @@ public function sendRequest(RequestInterface $request)
     public function sendAsyncRequest(RequestInterface $request)
     {
         $reactRequest = $this->buildReactRequest($request);
-        $deferred = new Deferred();
+        $promise = new Promise($this->loop);
 
-        $reactRequest->on('error', function (\Exception $error) use ($deferred, $request) {
-            $deferred->reject(new RequestException(
+        $reactRequest->on('error', function (\Exception $error) use ($promise, $request) {
+            $promise->reject(new RequestException(
                 $error->getMessage(),
                 $request,
                 $error
             ));
         });
 
-        $reactRequest->on('response', function (ReactResponse $reactResponse = null) use ($deferred, $reactRequest, $request) {
+        $reactRequest->on('response', function (ReactResponse $reactResponse = null) use ($promise, $request) {
             $bodyStream = $this->streamFactory->createStream();
             $reactResponse->on('data', function ($data) use (&$bodyStream) {
                 $bodyStream->write((string) $data);
             });
 
-            $reactResponse->on('end', function (\Exception $error = null) use ($deferred, $request, $reactResponse, &$bodyStream) {
+            $reactResponse->on('end', function (\Exception $error = null) use ($promise, $request, $reactResponse, &$bodyStream) {
                 $response = $this->buildResponse(
                     $reactResponse,
                     $bodyStream
                 );
                 if (null !== $error) {
-                    $deferred->reject(new HttpException(
+                    $promise->reject(new HttpException(
                         $error->getMessage(),
                         $request,
                         $response,
                         $error
                     ));
                 } else {
-                    $deferred->resolve($response);
+                    $promise->resolve($response);
                 }
             });
         });
 
         $reactRequest->end((string) $request->getBody());
 
-        $promise = new Promise($deferred->promise());
-        $promise->setLoop($this->loop);
-
         return $promise;
     }
 

src/Promise.php

@@ -3,7 +3,6 @@
 namespace Http\Adapter\React;
 
 use React\EventLoop\LoopInterface;
-use React\Promise\PromiseInterface as ReactPromise;
 use Http\Client\Exception;
 use Http\Promise\Promise as HttpPromise;
 use Psr\Http\Message\ResponseInterface;
@@ -12,8 +11,10 @@
  * React promise adapter implementation.
  *
  * @author Stéphane Hulard <stephane@hlrd.me>
+ *
+ * @internal
  */
-class Promise implements HttpPromise
+final class Promise implements HttpPromise
 {
     /**
      * Promise status.
@@ -22,13 +23,6 @@ class Promise implements HttpPromise
      */
     private $state = HttpPromise::PENDING;
 
-    /**
-     * Adapted React promise.
-     *
-     * @var ReactPromise
-     */
-    private $promise;
-
     /**
      * PSR7 received response.
      *
@@ -43,31 +37,26 @@ class Promise implements HttpPromise
      */
     private $exception;
 
+    /**
+     * @var callable|null
+     */
+    private $onFulfilled;
+
+    /**
+     * @var callable|null
+     */
+    private $onRejected;
+
     /**
      * React Event Loop used for synchronous processing.
      *
      * @var LoopInterface
      */
     private $loop;
 
-    /**
-     * Initialize the promise.
-     *
-     * @param ReactPromise $promise
-     */
-    public function __construct(ReactPromise $promise)
+    public function __construct(LoopInterface $loop)
     {
-        $promise->then(
-            function (ResponseInterface $response) {
-                $this->state = HttpPromise::FULFILLED;
-                $this->response = $response;
-            },
-            function (Exception $error) {
-                $this->state = HttpPromise::REJECTED;
-                $this->exception = $error;
-            }
-        );
-        $this->promise = $promise;
+        $this->loop = $loop;
     }
 
     /**
@@ -80,49 +69,110 @@ function (Exception $error) {
      */
     public function then(callable $onFulfilled = null, callable $onRejected = null)
     {
-        $this->promise->then(function () use ($onFulfilled) {
-            if (null !== $onFulfilled) {
-                call_user_func($onFulfilled, $this->response);
+        $newPromise = new self($this->loop);
+
+        $onFulfilled = $onFulfilled !== null ? $onFulfilled : function (ResponseInterface $response) {
+            return $response;
+        };
+
+        $onRejected = $onRejected !== null ? $onRejected : function (Exception $exception) {
+            throw $exception;
+        };
+
+        $this->onFulfilled = function (ResponseInterface $response) use ($onFulfilled, $newPromise) {
+            try {
+                $newPromise->resolve($onFulfilled($response));
+            } catch (Exception $exception) {
+                $newPromise->reject($exception);
             }
-        }, function () use ($onRejected) {
-            if (null !== $onRejected) {
-                call_user_func($onRejected, $this->exception);
+        };
+
+        $this->onRejected = function (Exception $exception) use ($onRejected, $newPromise) {
+            try {
+                $newPromise->resolve($onRejected($exception));
+            } catch (Exception $exception) {
+                $newPromise->reject($exception);
             }
-        });
+        };
 
-        return $this;
+        if ($this->state === HttpPromise::FULFILLED) {
+            $this->doResolve($this->response);
+        }
+
+        if ($this->state === HttpPromise::REJECTED) {
+            $this->doReject($this->exception);
+        }
+
+        return $newPromise;
     }
 
     /**
-     * {@inheritdoc}
+     * Resolve this promise.
+     *
+     * @param ResponseInterface $response
+     *
+     * @internal
      */
-    public function getState()
+    public function resolve(ResponseInterface $response)
     {
-        return $this->state;
+        if ($this->state !== HttpPromise::PENDING) {
+            throw new \RuntimeException('Promise is already resolved');
+        }
+
+        $this->state = HttpPromise::FULFILLED;
+        $this->response = $response;
+        $this->doResolve($response);
+    }
+
+    private function doResolve(ResponseInterface $response)
+    {
+        $onFulfilled = $this->onFulfilled;
+
+        if (null !== $onFulfilled) {
+            $onFulfilled($response);
+        }
     }
 
     /**
-     * Set EventLoop used for synchronous processing.
+     * Reject this promise.
      *
-     * @param LoopInterface $loop
+     * @param Exception $exception
      *
-     * @return Promise
+     * @internal
      */
-    public function setLoop(LoopInterface $loop)
+    public function reject(Exception $exception)
     {
-        $this->loop = $loop;
+        if ($this->state !== HttpPromise::PENDING) {
+            throw new \RuntimeException('Promise is already resolved');
+        }
+
+        $this->state = HttpPromise::REJECTED;
+        $this->exception = $exception;
+        $this->doReject($exception);
+    }
+
+    private function doReject(Exception $exception)
+    {
+        $onRejected = $this->onRejected;
 
-        return $this;
+        if (null !== $onRejected) {
+            $onRejected($exception);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getState()
+    {
+        return $this->state;
     }
 
     /**
      * {@inheritdoc}
      */
     public function wait($unwrap = true)
     {
-        if (null === $this->loop) {
-            throw new \LogicException('You must set the loop before wait!');
-        }
         while (HttpPromise::PENDING === $this->getState()) {
             $this->loop->tick();
         }

tests/PromiseTest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Http\Adapter\React\Tests;
+
+use GuzzleHttp\Psr7\Response;
+use Http\Adapter\React\Promise;
+use Http\Adapter\React\ReactFactory;
+use PHPUnit\Framework\TestCase;
+
+class PromiseTest extends TestCase
+{
+    private $loop;
+
+    public function setUp()
+    {
+        $this->loop = ReactFactory::buildEventLoop();
+    }
+
+    public function testChain()
+    {
+        $promise = new Promise($this->loop);
+        $response = new Response(200);
+
+        $lastPromise = $promise->then(function (Response $response) {
+            return $response->withStatus(300);
+        });
+
+        $promise->resolve($response);
+        $updatedResponse = $lastPromise->wait();
+
+        self::assertEquals(200, $response->getStatusCode());
+        self::assertEquals(300, $updatedResponse->getStatusCode());
+    }
+}