check only for containing string in utils::getJsonFromResponse, added…

… tests

README.md

@@ -275,5 +275,6 @@ $response = $client->getPage(0);
 
 ```php
 // can be possible null because the response body can be empty
-$json = \Sysix\LexOffice\Utils::getJsonFromResponse($response);
+$json = \Sysix\LexOffice\Utils::getJsonFromResponse($response); // as object
+$json = \Sysix\LexOffice\Utils::getJsonFromResponse($response, true); // as associative array
 ```

src/Utils.php

@@ -12,12 +12,12 @@
 
 class Utils
 {
-    public static function getJsonFromResponse(ResponseInterface $response): mixed
+    public static function getJsonFromResponse(ResponseInterface $response, bool $assoc = false): mixed
     {
         $body = $response->getBody()->__toString();
 
-        if ($response->getHeaderLine('Content-Type') === 'application/json') {
-            return self::jsonDecode($body);
+        if (str_contains($response->getHeaderLine('Content-Type'), 'application/json')) {
+            return self::jsonDecode($body, $assoc);
         }
 
         return null;

tests/UtilsTest.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sysix\LexOffice\Tests;
+
+use GuzzleHttp\Psr7\Response;
+use PHPUnit\Framework\TestCase;
+use Sysix\LexOffice\Utils;
+
+class UtilsTest extends TestCase
+{
+    public function testGetJsonFromResponseWithoutAnHeader(): void
+    {
+        $response = new Response();
+        $json = Utils::getJsonFromResponse($response);
+
+        $this->assertNull($json);
+    }
+
+    public function testGetJsonFromResponseWithInvalidHeader(): void
+    {
+        $response = new Response(200, [
+            'Content-Type' => 'application/xml'
+        ]);
+        $json = Utils::getJsonFromResponse($response);
+
+        $this->assertNull($json);
+    }
+
+    public function testGetJsonFromResponseWithValidHeader(): void
+    {
+        $response = new Response(200, [
+            'Content-Type' => 'application/json'
+        ], (string) json_encode([
+            'test' => true
+        ]));
+        $json = Utils::getJsonFromResponse($response);
+
+        $this->assertEquals((object)[
+            'test' => true
+        ], $json);
+    }
+
+    public function testGetJsonFromResponseWithValidCharsetHeader(): void
+    {
+        $response = new Response(200, [
+            'Content-Type' => 'application/json; charset=utf-8'
+        ], (string) json_encode([
+            'test' => true
+        ]));
+        $json = Utils::getJsonFromResponse($response);
+
+        $this->assertEquals((object)[
+            'test' => true
+        ], $json);
+    }
+}