JSON Schema for Responses object is incorrect in light of extensions

[ahl]

The 3.0.3 spec says this about the Responses object:

The Responses Object MUST contain at least one response code, and it SHOULD be the response for a successful operation call.

3.1.0 says something similar:

The Responses Object MUST contain at least one response code, and if only one response code is provided it SHOULD be the response for a successful operation call.

Here's the JSON Schema for 3.0.3:

    "Responses": {
      "type": "object",
      "properties": {
        "default": {
          "oneOf": [
            {
              "$ref": "#/definitions/Response"
            },
            {
              "$ref": "#/definitions/Reference"
            }
          ]
        }
      },
      "patternProperties": {
        "^[1-5](?:\\d{2}|XX)$": {
          "oneOf": [
            {
              "$ref": "#/definitions/Response"
            },
            {
              "$ref": "#/definitions/Reference"
            }
          ]
        },
        "^x-": {
        }
      },
      "minProperties": 1,
      "additionalProperties": false
    },

Note that the minProperties attempts to enforce the restriction noted above, but it inadvertently counts extensions. In other words, the following is valid according to the schema, but not according to the spec:

{
  "x-no-responses-at-all": "muahaha"
}

Note that 3.1 doesn't appear to try to enforce this in the schema:

    "responses": {
      "type": "object",
      "properties": {
        "default": {
          "$ref": "#/$defs/response-or-reference"
        }
      },
      "patternProperties": {
        "^[1-5](?:[0-9]{2}|XX)$": {
          "$ref": "#/$defs/response-or-reference"
        }
      },
      "$ref": "#/$defs/specification-extensions",
      "unevaluatedProperties": false
    },

[karenetheridge]

related: #2799

[ahl]

@karenetheridge how did you address this in #2799? It seems like extension properties would satisfy your minProperties: 1, no?

[karenetheridge]

Yes, there is no contains-like keyword for objects that specifies that a property matching a particular regex must be present.

Actually, I thought of a way... I have submitted it as #3093. \o/