handle Enum in response and request

[billyandco]

While using swager_parse library to generate retrofit from swagger
there's some case where enum can be use in queryParameter
and some case where enum can be used for response but will need a fromJson method on enum

you will check in this pull request that we tried to find a way to deal with it
but when json is a String and generator try to cast as Map<String, dynamic>, it can be broken
we made a solution for toJson on enum, but i think it can be handle inside retrofit generator

Carapacik/swagger_parser#18

[knyghtryda]

I'm currently running into this as well. The workaround is to create an extension on the enum for the toJson(), but this ideally should be handled by retrofit directly.

[sooxt98]

update: seems like the retrofit patch doesn't fix the issue, it still using .name

this could be solved all together with configuration below

# pubspec.yaml
swagger_parser:
  enums_to_json: true

# build.yaml
targets:
  $default:
    builders:
      json_serializable:
        options:
          explicit_to_json: true

#596
rrousselGit/freezed#86