Merged FAD-3148 into 2.x

* FAD-3148 basic non-functioning base class

* FAD-3148 a bit more functionality in the base class

* FAD-3148 added custom promise class and custom response class. Did good things to SparkPost class

* Updated Transmission.php for new refactor, still WIP. Created Resource.php as a parent class for all future resources.

* Removed test functions

* Cleaned up Transmissions.php according to PSR-2, deleted more test code and comments.

* added sync and aysnc, cleaned up code

* added support for async/sync option

* added support for async/sync option

* Added interns to authors

* simplified the request function

* added comments

* added user agent

* added comments in SparkPostPromise

* added comments in SparkPostException

* added comments in SparkPostResponse

* cleaning up test

* updated composer.json and contributing files for testing

* Ran php-cs-fixer

* testing for sparkpost response class

* updated to newer version of guzzle

* updated to newer version of guzzle

* Cleaned up getUrl and other functions

* cleaned up constructor and overrode getCode with getResponse()->getStatusCode()

* fixed up then method

* cleaned up getBody

* deleted old test

* Wrote total coverage tests for SparkPost class

* commented out setting up transmissions endpoint until merging with FAD-3146

1 files changed, 69 insertions, 0 deletions

diff --git a/lib/SparkPost/SparkPostPromise.php b/lib/SparkPost/SparkPostPromise.php
new file mode 100644
index 0000000..15f129f
--- /dev/null
+++ b/lib/SparkPost/SparkPostPromise.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace SparkPost;
+
+use Http\Promise\Promise as HttpPromise;
+
+class SparkPostPromise implements HttpPromise
+{
+    /**
+     * HttpPromise to be wrapped by SparkPostPromise.
+     */
+    private $promise;
+
+    /**
+     * set the promise to be wrapped.
+     *
+     * @param HttpPromise $promise
+     */
+    public function __construct(HttpPromise $promise)
+    {
+        $this->promise = $promise;
+    }
+
+    /**
+     * Hand off the response functions to the original promise and return a custom response or exception.
+     *
+     * @param callable $onFulfilled - function to be called if the promise is fulfilled
+     * @param callable $onRejected  - function to be called if the promise is rejected
+     */
+    public function then(callable $onFulfilled = null, callable $onRejected = null)
+    {
+        return $this->promise->then(function($response) use ($onFulfilled) {
+            if (isset($onFulfilled))
+                $onFulfilled(new SparkPostResponse($response));
+        }, function($exception) use ($onRejected) {
+            if (isset($onRejected))
+                $onRejected(new SparkPostException($exception));
+        });
+    }
+
+    /**
+     * Hand back the state.
+     *
+     * @return $state - returns the state of the promise
+     */
+    public function getState()
+    {
+        return $this->promise->getState();
+    }
+
+    /**
+     * Wraps the wait function and returns a custom response or throws a custom exception.
+     *
+     * @param bool $unwrap
+     *
+     * @return SparkPostResponse
+     *
+     * @throws SparkPostException
+     */
+    public function wait($unwrap = true)
+    {
+        try {
+            $response = $this->promise->wait($unwrap);
+            return $response ? new SparkPostResponse($response) : $response;
+        } catch (\Exception $exception) {
+            throw new SparkPostException($exception);
+        }
+    }
+}