Query parameters with ListFormat.multiCompatible still percent-encode square brackets

[fujidaiti]

Package

dio

Version

5.7.0

Operating-System

Android

Adapter

Default Dio

Output of flutter doctor -v

No response

Dart Version

3.3.2

Steps to Reproduce

Even when specifying ListFormat.multiCompatible, square brackets ([]) in query parameters are still percent-encoded.

For example, the expected request is:

https://example.com/v1/users?ids[]=4230&ids[]=394

However, it is actually encoded as:

https://example.com/v1/users?ids%5B%5D=4230&ids%5B%5D=394

During debugging my app, it was found that the final URL is constructed in the RequestOptions.url getter using Uri.parse(url).normalizePath(). In this process, it ends up encoding the square brackets regardless of the listFormat (the relevant code is here).

void main() {
  final url = Uri.parse('https://example.com/v1/users?ids[]=1&ids[]=2');
  print('${url.normalizePath()}'); // https://example.com/v1/users?ids%5B%5D=1&ids%5B%5D=2
}

I recently learned that RFC 3986 does not allow square brackets in query parameters. However, many major libraries, such as Laravel and Express, support the array syntax using square brackets in query strings, and it would be desirable for Dio to support this notation for compatibility reasons.

Expected Result

https://example.com/v1/users?ids[]=4230&ids[]=394

Actual Result

https://example.com/v1/users?ids%5B%5D=4230&ids%5B%5D=394

[fujidaiti]

Major libraries can handle encoded query strings nowadays, and the Uri class should follow RFC 3986...
I’m closing this, sorry for my silly question.