Optimized testing client which create the directory again when the directory does not exist. (#4119)

Co-authored-by: 李铭昕 <[email protected]>

Author: liuende501

src/Client.php

@@ -231,7 +231,9 @@ protected function normalizeFiles(array $multipart): array
 
                 $dir = BASE_PATH . '/runtime/uploads';
                 $tmpName = $dir . '/' . $filename;
-                $fileSystem->makeDirectory($dir);
+                if (! is_dir($dir)) {
+                    $fileSystem->makeDirectory($dir);
+                }
                 $fileSystem->put($tmpName, $contents);
 
                 $stats = fstat($contents);