* Added support for enums in Dart.
* Pick non-private names for enum values.
The _ prefix denotes a private member in Dart, so avoid generating enum values starting with this character.
* Properly encode enum values into query paramters.
* Various cleanups.
* Add support for x-enum-values extension.
Use class instead of enum for better ergonomy.
Better generated enum names.
* Fixed test.
* Support enum descriptions.
* fix: query params may be ints as well
don't assume query params are Strings or List<String>s
* fix dart: use correct type for QueryParams
type is Iterable, not List
only check params for != null if they haven't been checked already
add some casts to make strong mode happy
update petstore
* feat dart: enable strong mode
* feat dart: generate both browser and vm library
move petstore client into subdirectory and reference
generated libraries using path in pubspec.yaml
* feat dart: refactor petstore test.
The new layout resembles a real project.
petstore test is now strong mode compatible.
* feat: add DateTimerParser transformer
* feat: improved exception reporting
* feat[dart]: handle patch requests
* fix[dart]: typo
* fix dart: remove findPetsByTag test; enable strong-mode
find pets by tag call is deprecated and returns 500
generated library is now strong mode compatible
