Invariants Schema

Machine-readable schema for per-case invariants.

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://cityjson-corpus.org/schemas/invariants.schema.json",
  "title": "Shared Corpus Case Invariants",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "version",
    "id",
    "kind",
    "checks"
  ],
  "properties": {
    "version": {
      "type": "integer",
      "const": 1,
      "description": "Invariant metadata format version."
    },
    "id": {
      "type": "string",
      "minLength": 1,
      "description": "Stable case identifier."
    },
    "kind": {
      "type": "string",
      "enum": [
        "positive",
        "negative"
      ],
      "description": "Whether the fixture is expected to be accepted or rejected. See schemas/README.md for the controlled vocabulary."
    },
    "fixture": {
      "type": "string",
      "minLength": 1,
      "description": "Repo-relative fixture path for negative cases."
    },
    "expected_result": {
      "type": "string",
      "enum": [
        "accept",
        "reject"
      ],
      "description": "Expected outcome for the fixture."
    },
    "checks": {
      "type": "array",
      "minItems": 1,
      "uniqueItems": true,
      "items": {
        "$ref": "#/$defs/check"
      },
      "description": "Machine-readable checks for the case."
    }
  },
  "allOf": [
    {
      "if": {
        "properties": {
          "kind": {
            "const": "negative"
          }
        }
      },
      "then": {
        "required": [
          "fixture",
          "expected_result"
        ]
      }
    }
  ],
  "$defs": {
    "check": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "id",
        "description"
      ],
      "properties": {
        "id": {
          "type": "string",
          "minLength": 1,
          "description": "Stable identifier for the invariant check."
        },
        "description": {
          "type": "string",
          "minLength": 1,
          "description": "Human-readable description of the invariant."
        }
      }
    }
  }
}