Opening the possibility of injecting a PSR-18 compatible HTTP Client (mghoneimy#33)

* Opening the possibility of injecting a PSR-18 compatible HTTP Client

* The use of function stream_for() is discouraged

* Dropping $authorizationHeaders property

* README update

* Providing explanation for removing the headers from the options before creating a guzzle instance

Author: bbaga

README.md

@@ -353,6 +353,20 @@ $client = new Client(
 );
 ```
 
+
+It is possible to use your own preconfigured HTTP client that implements the [PSR-18 interface](https://www.php-fig.org/psr/psr-18/).
+
+Example:
+
+```php
+$client = new Client(
+    'http://api.graphql.com',
+    [],
+    [],
+    $myHttpClient
+);
+```
+
 # Running Queries
 
 ## Result Formatting

composer.json

@@ -31,6 +31,8 @@
     "require": {
         "php": "^7.1",
         "ext-json": "*",
+        "psr/http-message": "^1.0",
+        "psr/http-client": "^1.0",
         "guzzlehttp/guzzle": "^6.3"
     },
     "require-dev": {

src/Client.php

@@ -4,8 +4,12 @@
 
 use GraphQL\Exception\QueryError;
 use GraphQL\QueryBuilder\QueryBuilderInterface;
+use GraphQL\Util\GuzzleAdapter;
 use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Psr7\Request;
+use Psr\Http\Client\ClientInterface;
 use TypeError;
+use GuzzleHttp\Psr7;
 
 /**
  * Class Client
@@ -20,34 +24,41 @@ class Client
     protected $endpointUrl;
 
     /**
-     * @var array
-     */
-    protected $authorizationHeaders;
-
-    /**
-     * @var \GuzzleHttp\Client
+     * @var ClientInterface
      */
     protected $httpClient;
 
     /**
      * @var array
      */
-    protected $httpOptions;
-
+    protected $httpHeaders;
 
     /**
      * Client constructor.
      *
      * @param string $endpointUrl
      * @param array $authorizationHeaders
      * @param array $httpOptions
+     * @param ClientInterface $httpClient
      */
-    public function __construct(string $endpointUrl, array $authorizationHeaders = [], array $httpOptions = [])
+    public function __construct(string $endpointUrl, array $authorizationHeaders = [], array $httpOptions = [], ClientInterface $httpClient = null)
     {
+        $headers = array_merge(
+            $authorizationHeaders,
+            $httpOptions['headers'] ?? [],
+            ['Content-Type' => 'application/json']
+        );
+
+        /**
+         * All headers will be set on the request objects explicitly,
+         * Guzzle doesn't have to care about them at this point, so to avoid any conflicts
+         * we are removing the headers from the options
+         */
+        unset($httpOptions['headers']);
+
         $this->endpointUrl          = $endpointUrl;
-        $this->authorizationHeaders = $authorizationHeaders;
-        $this->httpClient           = new \GuzzleHttp\Client();
-        $this->httpOptions          = $httpOptions;
+        $this->httpClient           = $httpClient ?? new GuzzleAdapter(new \GuzzleHttp\Client($httpOptions));
+        $this->httpHeaders          = $headers;
     }
 
     /**
@@ -75,33 +86,28 @@ public function runQuery($query, bool $resultsAsArray = false, array $variables
      * @param string $queryString
      * @param bool   $resultsAsArray
      * @param array  $variables
+     * @param
      *
      * @return Results
      * @throws QueryError
      */
     public function runRawQuery(string $queryString, $resultsAsArray = false, array $variables = []): Results
     {
-        // Set request headers for authorization and content type
-        if (!empty($this->authorizationHeaders)) {
-            $options['headers'] = $this->authorizationHeaders;
-        }
+        $request = new Request('POST', $this->endpointUrl);
 
-        // Set request options for \GuzzleHttp\Client
-        if (!empty($this->httpOptions)) {
-            $options = $this->httpOptions;
+        foreach($this->httpHeaders as $header => $value) {
+            $request = $request->withHeader($header, $value);
         }
 
-        $options['headers']['Content-Type'] = 'application/json';
-
         // Convert empty variables array to empty json object
         if (empty($variables)) $variables = (object) null;
         // Set query in the request body
-        $bodyArray       = ['query' => (string) $queryString, 'variables' => $variables];
-        $options['body'] = json_encode($bodyArray);
+        $bodyArray = ['query' => (string) $queryString, 'variables' => $variables];
+        $request = $request->withBody(Psr7\stream_for(json_encode($bodyArray)));
 
         // Send api request and get response
         try {
-            $response = $this->httpClient->post($this->endpointUrl, $options);
+            $response = $this->httpClient->sendRequest($request);
         }
         catch (ClientException $exception) {
             $response = $exception->getResponse();
@@ -114,8 +120,6 @@ public function runRawQuery(string $queryString, $resultsAsArray = false, array
         }
 
         // Parse response to extract results
-        $results = new Results($response, $resultsAsArray);
-
-        return $results;
+        return new Results($response, $resultsAsArray);
     }
 }

src/Util/GuzzleAdapter.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace GraphQL\Util;
+
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\GuzzleException;
+use Psr\Http\Client;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
+
+class GuzzleAdapter implements Client\ClientInterface
+{
+    /**
+     * @var ClientInterface
+     */
+    private $client;
+
+    /**
+     * GuzzleAdapter constructor.
+     *
+     * @param ClientInterface $client
+     */
+    public function __construct(ClientInterface $client)
+    {
+        $this->client = $client;
+    }
+
+    /**
+     * @param RequestInterface $request
+     *
+     * @return ResponseInterface
+     * @throws GuzzleException
+     */
+    public function sendRequest(RequestInterface $request): ResponseInterface
+    {
+        /**
+         * We are not catching and converting the guzzle exceptions to psr-18 exceptions
+         * for backward-compatibility sake
+         */
+
+        return $this->client->send($request);
+    }
+}

tests/ClientTest.php

@@ -6,6 +6,7 @@
 use GraphQL\Exception\QueryError;
 use GraphQL\QueryBuilder\QueryBuilder;
 use GraphQL\RawObject;
+use GraphQL\Util\GuzzleAdapter;
 use GuzzleHttp\Exception\ClientException;
 use GuzzleHttp\Exception\ConnectException;
 use GuzzleHttp\Exception\ServerException;
@@ -41,7 +42,7 @@ protected function setUp(): void
     {
         $this->mockHandler = new MockHandler();
         $handler = HandlerStack::create($this->mockHandler);
-        $this->client      = new MockClient('', $handler);
+        $this->client      = new Client('', [], ['handler' => $handler]);
     }
 
     /**
@@ -61,16 +62,16 @@ public function testConstructClient()
         $mockHandler->append(new Response(200));
         $mockHandler->append(new Response(200));
 
-        $client = new MockClient('', $handler);
+        $client = new Client('', [], ['handler' => $handler]);
         $client->runRawQuery('query_string');
 
-        $client = new MockClient('', $handler, ['Authorization' => 'Basic xyz']);
+        $client = new Client('', ['Authorization' => 'Basic xyz'], ['handler' => $handler]);
         $client->runRawQuery('query_string');
 
-        $client = new MockClient('', $handler);
+        $client = new Client('', [], ['handler' => $handler]);
         $client->runRawQuery('query_string',  false, ['name' => 'val']);
 
-        $client = new MockClient('', $handler, ['Authorization' => 'Basic xyz'], ['headers' => [ 'Authorization' => 'Basic zyx', 'User-Agent' => 'test' ]]);
+        $client = new Client('', ['Authorization' => 'Basic xyz'], ['handler' => $handler, 'headers' => [ 'Authorization' => 'Basic zyx', 'User-Agent' => 'test' ]]);
         $client->runRawQuery('query_string');
 
         /** @var Request $firstRequest */