Add a factory method to Message to create from PSR-7 Requests (#20)

* Add a factory method to Message to create from PSR-7 Requests

* Direct Travis to use Trusty instead of Precise

* Do not require that PSR-7 requests have an SNS type header

* Revert X_AMZ_SNS_MESSAGE_TYPE header usage to its previous state

Author: jeskew

.travis.yml

@@ -5,9 +5,11 @@ php:
   - 5.5
   - 5.6
   - 7.0
+  - 7.1
   - hhvm
 
 sudo: false
+dist: trusty
 
 install:
   - travis_retry composer update --no-interaction --prefer-dist

composer.json

@@ -15,16 +15,15 @@
         "forum": "https://forums.aws.amazon.com/forum.jspa?forumID=80",
         "issues": "https://github.com/aws/aws-sns-message-validator/issues"
     },
-    "suggest": {
-        "aws/aws-sdk-php": "The official Amazon Web Services PHP SDK."
-    },
     "require": {
         "php": ">=5.4",
-        "ext-openssl": "*"
+        "ext-openssl": "*",
+        "psr/http-message": "^1.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.0",
-        "squizlabs/php_codesniffer": "^2.3"
+        "squizlabs/php_codesniffer": "^2.3",
+        "guzzlehttp/psr7": "^1.4"
     },
     "autoload": {
         "psr-4": { "Aws\\Sns\\": "src/" }

src/Message.php

@@ -1,6 +1,8 @@
 <?php
 namespace Aws\Sns;
 
+use Psr\Http\Message\RequestInterface;
+
 /**
  * Represents an SNS message received over http(s).
  */
@@ -21,7 +23,7 @@ class Message implements \ArrayAccess, \IteratorAggregate
     private $data;
 
     /**
-     * Creates a message object from the raw POST data
+     * Creates a Message object from the raw POST data
      *
      * @return Message
      * @throws \RuntimeException If the POST data is absent, or not a valid JSON document
@@ -33,8 +35,30 @@ public static function fromRawPostData()
             throw new \RuntimeException('SNS message type header not provided.');
         }
 
-        // Read the raw POST data and JSON-decode it.
-        $data = json_decode(file_get_contents('php://input'), true);
+        // Read the raw POST data and JSON-decode it into a message.
+        return self::fromJsonString(file_get_contents('php://input'));
+    }
+
+    /**
+     * Creates a Message object from a PSR-7 Request or ServerRequest object.
+     *
+     * @param RequestInterface $request
+     * @return Message
+     */
+    public static function fromPsrRequest(RequestInterface $request)
+    {
+        return self::fromJsonString($request->getBody());
+    }
+
+    /**
+     * Creates a Message object from a JSON-decodable string.
+     *
+     * @param string $requestBody
+     * @return Message
+     */
+    private static function fromJsonString($requestBody)
+    {
+        $data = json_decode($requestBody, true);
         if (JSON_ERROR_NONE !== json_last_error() || !is_array($data)) {
             throw new \RuntimeException('Invalid POST data.');
         }

tests/MessageTest.php

@@ -1,8 +1,10 @@
 <?php
 namespace Aws\Sns;
 
+use GuzzleHttp\Psr7\Request;
+
 /**
- * @covers Aws\Sns\Message
+ * @covers \Aws\Sns\Message
  */
 class MessageTest extends \PHPUnit_Framework_TestCase
 {
@@ -141,6 +143,32 @@ public function testCreateFromRawPostFailsWithMissingData()
         unset($_SERVER['HTTP_X_AMZ_SNS_MESSAGE_TYPE']);
     }
 
+    public function testCanCreateFromPsr7Request()
+    {
+        $request = new Request(
+            'POST',
+            '/',
+            [],
+            json_encode($this->messageData)
+        );
+        $message = Message::fromPsrRequest($request);
+        $this->assertInstanceOf('Aws\Sns\Message', $message);
+    }
+
+    /**
+     * @expectedException \RuntimeException
+     */
+    public function testCreateFromPsr7RequestFailsWithMissingData()
+    {
+        $request = new Request(
+            'POST',
+            '/',
+            [],
+            'Not valid JSON'
+        );
+        Message::fromPsrRequest($request);
+    }
+
     public function testArrayAccess()
     {
         $message = new Message($this->messageData);