[dart-dio][client] Generated code for property that is array type with default value does not compile

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?

Description

Support for default values was added in #8201 by @kuhnroyal. Now when array type with default value which is an empty array [] is in the spec, dart code that does not compile is generated:

pets:
  type: array
  items:
    $ref: '#/components/schemas/Pet'
  default: []

Error as follows:

A value of type 'List<dynamic>' can't be assigned to a variable of type 'ListBuilder<Pet>'.

Snippet of generated code causing the issue:

@nullable
@BuiltValueField(wireName: r'pets')
BuiltList<Pet> get pets;

static void _initializeBuilder(OrderBuilder b) => b
    ..pets = [] // <-- line causing error
    ..complete = false;

openapi-generator version

master

Steps to reproduce

You can reproduce the issue by running the dart-dio generator for this modified petstore example here

Related issues/PRs

#8201 by @kuhnroyal is where the issue appears to be introduced

@swipesight (2018/09) @jaumard (2018/09) @josh-burton (2019/12) @amondnet (2019/12) @sbu-WBT (2020/12) @kuhnroyal (2020/12) @agilob (2020/12)

[adg-mh]

@kuhnroyal That was the petstore example I just cobbled in the extra bits to see how it would act. I don’t actually need that functionality now, I was just checking to see if it validated.

Haven’t tested yet but it looks like the fixes in your PR cover my case.

[kuhnroyal]

@adg-mh Where is this config from that you have there?