Changing the multipart form-data behavior to use the form name as an array, which makes it recognizable as an array by PHP on the $_POST globals once it is coming from the HttpClient component

Author: jvahldick

Part/Multipart/FormDataPart.php

@@ -56,11 +56,20 @@ public function getParts(): array
     private function prepareFields(array $fields): array
     {
         $values = [];
-        array_walk_recursive($fields, function ($item, $key) use (&$values) {
-            if (!\is_array($item)) {
-                $values[] = $this->preparePart($key, $item);
+
+        $prepare = function ($item, $key, $root = null) use (&$values, &$prepare) {
+            $fieldName = $root ? sprintf('%s[%s]', $root, $key) : $key;
+
+            if (\is_array($item)) {
+                array_walk($item, $prepare, $fieldName);
+
+                return;
             }
-        });
+
+            $values[] = $this->preparePart($fieldName, $item);
+        };
+
+        array_walk($fields, $prepare);
 
         return $values;
     }

Tests/Part/Multipart/FormDataPartTest.php

@@ -47,6 +47,34 @@ public function testConstructor()
         $this->assertEquals([$t, $b, $c], $f->getParts());
     }
 
+    public function testNestedArrayParts()
+    {
+        $p1 = new TextPart('content', 'utf-8', 'plain', '8bit');
+        $f = new FormDataPart([
+            'foo' => clone $p1,
+            'bar' => [
+                'baz' => [
+                    clone $p1,
+                    'qux' => clone $p1,
+                ],
+            ],
+        ]);
+
+        $this->assertEquals('multipart', $f->getMediaType());
+        $this->assertEquals('form-data', $f->getMediaSubtype());
+
+        $p1->setName('foo');
+        $p1->setDisposition('form-data');
+
+        $p2 = clone $p1;
+        $p2->setName('bar[baz][0]');
+
+        $p3 = clone $p1;
+        $p3->setName('bar[baz][qux]');
+
+        $this->assertEquals([$p1, $p2, $p3], $f->getParts());
+    }
+
     public function testToString()
     {
         $p = DataPart::fromPath($file = __DIR__.'/../../Fixtures/mimetypes/test.gif');