docs: add docs

projektdokumentation/Listings/UnitTest.php

@@ -0,0 +1,39 @@
+<?php declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+use Neusta\IntexClient\Connection\Factory;
+use Neusta\IntexClient\Connection\Model\CustomerConnection;
+
+class FactoryTest extends TestCase
+{
+    /**
+     * @var Factory
+     */
+    private $subject;
+
+    public function setUp()
+    {
+        $this->subject = new Factory();
+    }
+
+    /**
+     * @test
+     */
+    public function createMustReturnInstanceOfCustomerConnectionWithValidIdentifierGiven()
+    {
+        $expectedInstance = $this->subject->create('customer');
+
+        self::assertInstanceOf(CustomerConnection::class, $expectedInstance);
+    }
+
+    /**
+     * @test
+     * @throws RuntimeException
+     */
+    public function createMustThrowRuntimeExceptionIfInvalidIdentifierIsGiven()
+    {
+        $unexpectedInstance = $this->subject->create('fooBar');
+
+        self::expectException(RuntimeException::class);
+    }
+}