Issues with type array when type is (object | array) | "null"

[mattoni]

I've noticed an issue with the latest update to support type arrays per 3.1.0 spec (thanks a ton for adding that!)

However, I've noticed if the type is

type:
      - array
      - "null"

or

type:
      - object
      - "null"

The null is not included in the final type. For example, this type from my spec:

title: LoadBalancerLatestTelemetryController
type: object
required:
  - time
  - controller
properties:
  time:
    $ref: ../../../../DateTime.yml
  controller:
    $ref: ../../../../Identifier.yml
  instances:
    type:
      - array
      - "null"
    items:
      $ref: ./LoadBalancerLatestTelemetryInstance.yml

generated the following code:

export type LoadBalancerLatestTelemetryController = {
    time: DateTime;
    controller: Identifier;
    instances?: LoadBalancerLatestTelemetryInstance[];
};

or, in the case of object, this:

title: PromoCode
type: object
description: A billing promo code.
required:
  - code
  - credit
  - expires
  - state
properties:
  code:
    type: string
    description: The promo "code".
  credit:
    type:
      - object
      - "null"
    description: The amount of credit the promo code offers.
    additionalProperties:
      type: object
      properties:
        amount:
          "$ref": "./BillingAmount.yml"
        expires:
          "$ref": "../DateTime.yml"
  state:
    title: PromoCodeState
    allOf:
      - required:
          - current
        properties:
          current:
            description: The current state of the promo code.
            type: string
            enum:
              - live
              - deleted
      - "$ref": "../State.yml"

generates this:

export type PromoCode = {
    /** The promo "code". */
    code: string;
    /** The amount of credit the promo code offers. */
    credit: {
        [key: string]: {
            amount?: BillingAmount;
            expires?: DateTime;
        };
    };
    state: {
        /** The current state of the promo code. */
        current: "live" | "deleted";
    } & State;
};

Every other type seems to work, and using anyOf seems to work as well:

property:
  anyOf:
    - $ref: xyz.yml
    - type: "null"

So it just seems to be these two cases that I've found so far. Any help is appreciated!

[Xiphe]

Hi @mattoni, thank for reporting this 👍

To be clear, the expected outcome for your first example would be

export type LoadBalancerLatestTelemetryController = {
    time: DateTime;
    controller: Identifier;
    instances?: LoadBalancerLatestTelemetryInstance[];
} | null;

right?

[mattoni]

No, it'd be

export type LoadBalancerLatestTelemetryController = {
    time: DateTime;
    controller: Identifier;
    instances?: LoadBalancerLatestTelemetryInstance[] | null;
} 

where the instances field is also nullable.

[Xiphe]

my bad, yeah - that makes sense!