Fix broken "array"-typed properties

Resolves: #205
Close: #206

src/JsonMapper.php

@@ -242,7 +242,9 @@ public function map($json, $object)
             } else if ($this->isObjectOfSameType($type, $jvalue)) {
                 $this->setProperty($object, $accessor, $jvalue);
                 continue;
-            } else if ($this->isSimpleType($type) && !is_array($jvalue)) {
+            } else if ($this->isSimpleType($type)
+                && !(is_array($jvalue) && $this->hasVariadicArrayType($accessor))
+            ) {
                 if ($type === 'string' && is_object($jvalue)) {
                     throw new JsonMapper_Exception(
                         'JSON property "' . $key . '" in class "'

tests/Array_PHP74_Test.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for JsonMapper's support for PHP 7.4 typed arrays
+ *
+ * @category Tools
+ * @package  JsonMapper
+ * @author   Martin Reinfandt <martin.reinfandt@check24.de>
+ * @license  OSL-3.0 http://opensource.org/licenses/osl-3.0
+ * @link     https://github.com/cweiske/jsonmapper
+ * @requires PHP 7.4
+ */
+class Array_PHP74_Test extends TestCase
+{
+    protected function setUp(): void
+    {
+        require_once 'JsonMapperTest/PHP74_Array.php';
+    }
+
+    public function testJsonMapper()
+    {
+        $json = json_decode('{"files": ["test.txt"]}');
+        $jsonMapper = new \JsonMapper();
+        $array = $jsonMapper->map($json, new PHP74_Array());
+        self::assertCount(1, $array->files);
+    }
+}

tests/JsonMapperTest/PHP74_Array.php

@@ -0,0 +1,8 @@
+<?php
+
+declare(strict_types=1);
+
+class PHP74_Array
+{
+    public array $files;
+}