fix: multipart encoding for file arrays

Author: stainless-app[bot]

lib/orb/internal/util.rb

@@ -610,6 +610,7 @@ def encode_query_params(query)
         #
         # @return [Array(String, Enumerable<String>)]
         private def encode_multipart_streaming(body)
+          # rubocop:disable Style/CaseEquality
           # RFC 1521 Section 7.2.1 says we should have 70 char maximum for boundary length
           boundary = SecureRandom.urlsafe_base64(46)
 
@@ -619,7 +620,7 @@ def encode_query_params(query)
             in Hash
               body.each do |key, val|
                 case val
-                in Array if val.all? { primitive?(_1) }
+                in Array if val.all? { primitive?(_1) || Orb::Internal::Type::FileInput === _1 }
                   val.each do |v|
                     write_multipart_chunk(y, boundary: boundary, key: key, val: v, closing: closing)
                   end
@@ -635,6 +636,7 @@ def encode_query_params(query)
 
           fused_io = fused_enum(strio) { closing.each(&:call) }
           [boundary, fused_io]
+          # rubocop:enable Style/CaseEquality
         end
 
         # @api private