Add ProjectionsManager::reset method

resolves #41

src/Projections/ProjectionsClient.php

@@ -485,6 +485,25 @@ public function updateQuery(
         );
     }
 
+    public function reset(
+        EndPoint $endPoint,
+        string $name,
+        ?UserCredentials $userCredentials = null,
+        string $httpSchema = EndpointExtensions::HTTP_SCHEMA
+    ): Promise {
+        return $this->sendPost(
+            EndpointExtensions::formatStringToHttpUrl(
+                $endPoint,
+                $httpSchema,
+                '/projection/%s/command/reset',
+                $name
+            ),
+            '',
+            $userCredentials,
+            HttpStatusCode::OK
+        );
+    }
+
     public function delete(
         EndPoint $endPoint,
         string $name,

src/Projections/ProjectionsManager.php

@@ -418,4 +418,21 @@ public function deleteAsync(
             $this->httpSchema
         );
     }
+
+    /**
+     * Asynchronously resets a projection
+     */
+    public function resetAsync(string $name, ?UserCredentials $userCredentials = null): Promise
+    {
+        if ('' === $name) {
+            throw new InvalidArgumentException('Name is required');
+        }
+
+        return $this->client->reset(
+            $this->httpEndPoint,
+            $name,
+            $userCredentials,
+            $this->httpSchema
+        );
+    }
 }

tests/when_resetting_projections.php

@@ -0,0 +1,93 @@
+<?php
+
+/**
+ * This file is part of `prooph/event-store-client`.
+ * (c) 2018-2018 prooph software GmbH <contact@prooph.de>
+ * (c) 2018-2018 Sascha-Oliver Prolic <saschaprolic@googlemail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ProophTest\EventStoreClient;
+
+use Amp\Delayed;
+use Generator;
+use PHPUnit\Framework\TestCase;
+use Prooph\EventStoreClient\Util\Guid;
+use Throwable;
+
+class when_resetting_projections extends TestCase
+{
+    use ProjectionSpecification;
+
+    /** @var string */
+    private $projectionName;
+    /** @var string */
+    private $streamName;
+    /** @var string */
+    private $query;
+
+    public function given(): Generator
+    {
+        $id = Guid::generateAsHex();
+        $this->projectionName = 'when_resetting_projections-' . $id;
+        $this->streamName = 'test-stream-' . $id;
+
+        yield $this->postEvent($this->streamName, 'testEvent', '{"A": 1}');
+        yield $this->postEvent($this->streamName, 'testEvent', '{"A": 2}');
+
+        $this->query = $this->createStandardQuery($this->streamName);
+
+        yield $this->projectionsManager->createContinuousAsync(
+            $this->projectionName,
+            $this->query,
+            false,
+            'JS',
+            $this->credentials
+        );
+    }
+
+    protected function when(): Generator
+    {
+        yield $this->projectionsManager->resetAsync(
+            $this->projectionName,
+            $this->credentials
+        );
+    }
+
+    /**
+     * @test
+     * @throws Throwable
+     */
+    public function should_reset_the_projection(): void
+    {
+        $this->execute(function () {
+            $projectionStatus = \json_decode(
+                yield $this->projectionsManager->getStatusAsync(
+                    $this->projectionName,
+                    $this->credentials
+                ),
+                true
+            );
+            $status = $projectionStatus['status'];
+
+            $this->assertStringStartsWith('Preparing', $status);
+
+            yield new Delayed(500);
+
+            $projectionStatus = \json_decode(
+                yield $this->projectionsManager->getStatusAsync(
+                    $this->projectionName,
+                    $this->credentials
+                ),
+                true
+            );
+            $status = $projectionStatus['status'];
+
+            $this->assertSame('Running', $status);
+        });
+    }
+}