Show minProperties/maxProperties constraints for additionalProperties

[codyaray]

It seems like a bug or missing feature that Redoc-powered API docs don't show constraints for additionalProperties.

For example, when we indicate minItems: 1 on an array, it shows the non-empty flag:

But there's no such equivalent indicator on the nested additionalProperties field below, which uses minProperties: 1. Likewise, there's no indicator that it should be exactly 1 in this case, because there's also maxProperties: 1 as well.

Here's a snippet of the OpenAPI that produced the above screenshot

  SubscriptionRule:
    type: object
    required:
    - clauses
    properties:
      clauses:
        type: array
        minItems: 1
        description: |
          A rule can have multiple clauses, all of which must match for the rule to match.
          In other words, multiples clauses are `AND`'d together for evaluation.
        items:
          '$ref': '#/components/schemas/SubscriptionClause'

  SubscriptionClause:
    oneOf:
      ...
      - type: object
        description: Filter for alerts with properties that match the given name and value (exact string match)
        additionalProperties:
          type: string
          description: The name and value of the alert attribute to match
        minProperties: 1
        maxProperties: 1
        example:
          severity: info

Note: I'm sure there are complications, e.g., OpenAPI supports minProperties/maxProperties on objects with existing properties, not just the free-form additionalProperties field. So some design decisions will need to be made here. 😬

[freddrake]

minProperties / maxProperties definitely need to be indicated somehow, and they aren't restricted to when additionalProperties is true.

This is something I've run into as well.

[runeksvendsen]

I'm experiencing this issue as well. The spec looks like this:

"CreateBookingResponse": {
    "required": ["booking_id", "booking_status"],
    "properties": {
        "booking_id": {
            "type": "integer"
        },
        "booking_status": {
            "$ref": "#/definitions/BookingStatus"
        }
    },
    "type": "object"
},
"BookingStatus": {
    "properties": {
        "table_ready": {
            "required": ["seats"],
            "type": "object",
            "properties": {
                "seats": {
                    "items": {
                        "type": "integer"
                    },
                    "type": "array"
                }
            }
        },
        "waiting_list": {
            "required": ["duration_seconds"],
            "type": "object",
            "properties": {
                "duration_seconds": {
                    "type": "integer"
                }
            }
        }
    },
    "maxProperties": 1,
    "minProperties": 1,
    "type": "object"
},

which is rendered by ReDoc like so:

In other words, for the booking_status object, ReDoc makes it look like both the table_ready and waiting_list properties may be present in the response, when in fact only one of them are allowed to be there.