{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://docs.mutastic.io/schemas/rules/v1.json",
  "title": "mutastic rules file, v1",
  "description": "A rules file: call operators as data, a plugin listed under `plugins:` in `mutastic.yaml`. Each list item is one operator. mutastic reads each value as text, a list as text separated by commas, and a field it doesn't know as an error. See https://docs.mutastic.io/guides/plugins/#rules-files.",
  "type": "array",
  "items": { "$ref": "#/$defs/rule" },
  "$defs": {
    "text": {
      "type": "string",
      "minLength": 1
    },
    "list": {
      "type": "string",
      "minLength": 1,
      "description": "A list, separated by commas, on one line."
    },
    "rule": {
      "type": "object",
      "description": "One call operator.",
      "required": ["id", "explanation", "owners", "methods", "rewrite", "headline", "help"],
      "additionalProperties": false,
      "patternProperties": {
        "^(headline|help)\\.[^.]+$": {
          "$ref": "#/$defs/text",
          "description": "`headline` or `help` for one of the methods: `headline.sorted`, used for that method instead."
        }
      },
      "properties": {
        "id": {
          "type": "string",
          "pattern": "^[a-z0-9-]+/[a-z0-9-]+$",
          "description": "`namespace/name`, lower case: how reports, `--operators` and ignores name it.",
          "examples": ["bigdecimal/swap-arithmetic"]
        },
        "explanation": {
          "$ref": "#/$defs/text",
          "description": "What it changes, and when a test misses that: shown by `mutastic explain`."
        },
        "tier": {
          "enum": ["defaults", "stronger", "extended"],
          "description": "The set it's in: `defaults` (unless it says), `stronger` or `extended`."
        },
        "owners": {
          "$ref": "#/$defs/list",
          "description": "The types whose calls it matches, in full: `java.lang.String`."
        },
        "methods": {
          "$ref": "#/$defs/list",
          "description": "The method names it matches."
        },
        "descriptors": {
          "$ref": "#/$defs/list",
          "description": "The overloads it matches, as the JVM writes them: `(Ljava/lang/String;)Z`. Every overload if it's left out."
        },
        "since": {
          "type": ["integer", "string"],
          "pattern": "^[0-9]{1,3}$",
          "minimum": 0,
          "maximum": 999,
          "description": "The Java release the rewrite needs: `11`. In a class file for an older one, its mutants are skipped as unviable."
        },
        "rewrite": {
          "type": "string",
          "pattern": "^(remove|omit last argument|unchecked arithmetic|keep argument|rename \\w+->\\w+(\\s*,\\s*\\w+->\\w+)*\\s*,?|call \\w+\\([^)]*\\)( with .+)?)$",
          "description": "What the call becomes: `remove`, `rename a->b, c->d`, `omit last argument`, `unchecked arithmetic`, `keep argument`, or `call name(ARGS) with A, B`."
        },
        "source": {
          "$ref": "#/$defs/text",
          "description": "How a `call` rewrite reads in the source, for its label: `first(Long.MAX_VALUE)`."
        },
        "changed": {
          "$ref": "#/$defs/text",
          "description": "What the line now does, in a code frame: `stage removed`. `{to}` is what a rename calls instead."
        },
        "headline": {
          "$ref": "#/$defs/text",
          "description": "A missed mutant's headline, the gap in the tests. `{name}` is the method called, `{to}` what a rename calls instead, and `{method}` the method the call is in."
        },
        "help": {
          "$ref": "#/$defs/text",
          "description": "The test to write, with the same placeholders as `headline`."
        }
      }
    }
  }
}