Add Promise class

Author: jsor

src/React/Promise/Promise.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace React\Promise;
+
+class Promise implements PromiseInterface
+{
+    private $deferred;
+
+    public function __construct($resolver, $canceller = null)
+    {
+        if (!is_callable($resolver)) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    'The resolver arguments must be of type callable, %s given.',
+                    gettype($resolver)
+                )
+            );
+        }
+
+        $this->deferred = new Deferred();
+        $this->call($resolver);
+    }
+
+    public function then($fulfilledHandler = null, $errorHandler = null, $progressHandler = null)
+    {
+        return $this->deferred->then($fulfilledHandler, $errorHandler, $progressHandler);
+    }
+
+    private function call($callback)
+    {
+        try {
+            $callback(
+                array($this->deferred, 'resolve'),
+                array($this->deferred, 'reject'),
+                array($this->deferred, 'progress')
+            );
+        } catch (\Exception $e) {
+            $this->deferred->reject($e);
+        }
+    }
+}

tests/React/Promise/PromiseTest.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace React\Promise;
+
+/**
+ * @group Promise
+ */
+class PromiseTest extends TestCase
+{
+    /** @test */
+    public function shouldThrowIfResolverIsNotACallable()
+    {
+        $this->setExpectedException('\InvalidArgumentException');
+
+        new Promise(null);
+    }
+
+    /** @test */
+    public function shouldResolve()
+    {
+        $promise = new Promise(function($resolve) {
+            $resolve(1);
+        });
+
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($this->identicalTo(1));
+
+        $promise->then($mock);
+    }
+
+    /** @test */
+    public function shouldReject()
+    {
+        $promise = new Promise(function($_, $reject) {
+            $reject(1);
+        });
+
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($this->identicalTo(1));
+
+        $promise->then($this->expectCallableNever(), $mock);
+    }
+
+    /** @test */
+    public function shouldProgres()
+    {
+        $promise = new Promise(function($_, $_, $progress) use (&$notify) {
+            $notify = $progress;
+        });
+
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($this->identicalTo(1));
+
+        $promise->then($this->expectCallableNever(), $this->expectCallableNever(), $mock);
+
+        $notify(1);
+    }
+}