Add support for prometheus/pushgateway:>=0.10 (#17)

* allow status 202 in case of downwards compatibility
* add allowance of status 200 for prometheus/pushgateway >=0.10.0 
* fix grouping key, because of not matching declerations
* simplify if to add more status code easier

Author: kswzr

src/Prometheus/PushGateway.php

@@ -4,6 +4,7 @@
 namespace Prometheus;
 
 use GuzzleHttp\Client;
+use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\GuzzleException;
 use RuntimeException;
 
@@ -14,13 +15,20 @@ class PushGateway
      */
     private $address;
 
+    /**
+     * @var ClientInterface
+     */
+    private $client;
+
     /**
      * PushGateway constructor.
-     * @param $address string host:port of the push gateway
+     * @param string $address host:port of the push gateway
+     * @param ClientInterface $client
      */
-    public function __construct($address)
+    public function __construct($address, ClientInterface $client = null)
     {
         $this->address = $address;
+        $this->client = $client ?? new Client();
     }
 
     /**
@@ -31,7 +39,7 @@ public function __construct($address)
      * @param array $groupingKey
      * @throws GuzzleException
      */
-    public function push(CollectorRegistry $collectorRegistry, string $job, array $groupingKey = null): void
+    public function push(CollectorRegistry $collectorRegistry, string $job, array $groupingKey = []): void
     {
         $this->doRequest($collectorRegistry, $job, $groupingKey, 'put');
     }
@@ -44,7 +52,7 @@ public function push(CollectorRegistry $collectorRegistry, string $job, array $g
      * @param $groupingKey
      * @throws GuzzleException
      */
-    public function pushAdd(CollectorRegistry $collectorRegistry, string $job, array $groupingKey = null): void
+    public function pushAdd(CollectorRegistry $collectorRegistry, string $job, array $groupingKey = []): void
     {
         $this->doRequest($collectorRegistry, $job, $groupingKey, 'post');
     }
@@ -56,7 +64,7 @@ public function pushAdd(CollectorRegistry $collectorRegistry, string $job, array
      * @param array $groupingKey
      * @throws GuzzleException
      */
-    public function delete(string $job, array $groupingKey = null): void
+    public function delete(string $job, array $groupingKey = []): void
     {
         $this->doRequest(null, $job, $groupingKey, 'delete');
     }
@@ -76,21 +84,22 @@ private function doRequest(CollectorRegistry $collectorRegistry, string $job, ar
                 $url .= "/" . $label . "/" . $value;
             }
         }
-        $client = new Client();
+
         $requestOptions = [
             'headers' => [
                 'Content-Type' => RenderTextFormat::MIME_TYPE,
             ],
             'connect_timeout' => 10,
             'timeout' => 20,
         ];
+
         if ($method != 'delete') {
             $renderer = new RenderTextFormat();
             $requestOptions['body'] = $renderer->render($collectorRegistry->getMetricFamilySamples());
         }
-        $response = $client->request($method, $url, $requestOptions);
+        $response = $this->client->request($method, $url, $requestOptions);
         $statusCode = $response->getStatusCode();
-        if ($statusCode != 202) {
+        if (!in_array($statusCode, [200, 202])) {
             $msg = "Unexpected status code "
                 . $statusCode
                 . " received from push gateway "

tests/Test/Prometheus/PushGatewayTest.php

@@ -0,0 +1,79 @@
+<?php
+
+namespace Test\Prometheus;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Psr7\Response;
+use PHPUnit\Framework\TestCase;
+use Prometheus\CollectorRegistry;
+use Prometheus\MetricFamilySamples;
+use Prometheus\PushGateway;
+
+class PushGatewayTest extends TestCase
+{
+    /**
+     * @test
+     *
+     * @doesNotPerformAssertions
+     */
+    public function validResponseShouldNotThrowException(): void
+    {
+        $mockedCollectorRegistry = $this->createMock(CollectorRegistry::class);
+        $mockedCollectorRegistry->method('getMetricFamilySamples')->with()->willReturn([
+            $this->createMock(MetricFamilySamples::class)
+        ]);
+
+        $mockHandler = new MockHandler([
+            new Response(200),
+            new Response(202),
+        ]);
+        $handler = HandlerStack::create($mockHandler);
+        $client = new Client(['handler' => $handler]);
+
+        $pushGateway = new PushGateway('http://foo.bar', $client);
+        $pushGateway->push($mockedCollectorRegistry, 'foo');
+    }
+
+    /**
+     * @test
+     *
+     * @doesNotPerformAnyAssertions
+     */
+    public function invalidResponseShouldThrowRuntimeException(): void
+    {
+        $this->expectException(\RuntimeException::class);
+
+        $mockedCollectorRegistry = $this->createMock(CollectorRegistry::class);
+        $mockedCollectorRegistry->method('getMetricFamilySamples')->with()->willReturn([
+            $this->createMock(MetricFamilySamples::class)
+        ]);
+
+        $mockHandler = new MockHandler([
+            new Response(201),
+            new Response(300),
+        ]);
+        $handler = HandlerStack::create($mockHandler);
+        $client = new Client(['handler' => $handler]);
+
+        $pushGateway = new PushGateway('http://foo.bar', $client);
+        $pushGateway->push($mockedCollectorRegistry, 'foo');
+    }
+
+    /**
+     * @test
+     */
+    public function clientGetsDefinedIfNotSpecified(): void
+    {
+        $this->expectException(\RuntimeException::class);
+
+        $mockedCollectorRegistry = $this->createMock(CollectorRegistry::class);
+        $mockedCollectorRegistry->method('getMetricFamilySamples')->with()->willReturn([
+            $this->createMock(MetricFamilySamples::class)
+        ]);
+
+        $pushGateway = new PushGateway('http://foo.bar');
+        $pushGateway->push($mockedCollectorRegistry, 'foo');
+    }
+}