Playground¶

Try out Mustang's criteria evaluation directly in your browser. Write a Criteria (DNF or CNF) and an Event (the JSON object representing an incoming event), then click Evaluate to see whether the criteria matches — along with a per-predicate debug trace.

Client-side only

This playground runs entirely in JavaScript. It mirrors Mustang's Java evaluation logic for the most common predicate and detail types. No data leaves your browser.

Supported features¶

Feature	Supported
`DNFCriteria` (conjunctions of predicates)	✅
`CNFCriteria` (disjunctions of predicates)	✅
`IncludedPredicate`	✅
`ExcludedPredicate`	✅
`EqualityDetail`	✅
`INDetail` (set membership)	✅
`RangeDetail` (numeric)	✅
`ExistenceDetail`	✅
`NonExistenceDetail`	✅
`RegexDetail`	✅
`VersioningDetail`	✅
`ContainsDetail`	✅
`AnyDetail`	✅
`UNFCriteria` (arbitrary nesting)	❌ (use `evaluate()` API in Java)
`PreOperation` transforms	❌ (apply transforms to your event JSON manually)
JSONPath `lhs` expressions	❌ (use simple dot-path keys e.g. `$.age`)

Load example:

Criteria JSON

Event JSON (RequestContext payload)

Enter criteria and event JSON above, then click Evaluate.

Criteria JSON reference¶

DNFCriteria¶

{
  "@type": "DNFCriteria",
  "id": "my-criteria",
  "conjunctions": [
    {
      "predicates": [
        {
          "@type": "IncludedPredicate",
          "lhs": "$.fieldName",
          "detail": { "@type": "EqualityDetail", "value": "expected" }
        }
      ]
    }
  ]
}

The criteria matches if any conjunction matches (OR of AND-groups).

CNFCriteria¶

{
  "@type": "CNFCriteria",
  "id": "my-criteria",
  "disjunctions": [
    {
      "predicates": [
        {
          "@type": "IncludedPredicate",
          "lhs": "$.fieldName",
          "detail": { "@type": "INDetail", "values": ["a", "b"] }
        }
      ]
    }
  ]
}

The criteria matches if every disjunction matches (AND of OR-groups).

Detail types quick reference¶

`@type`	Required fields	Notes
`EqualityDetail`	`value`	String comparison
`INDetail`	`values` (array)	Value must be in list
`RangeDetail`	`lowerBound`, `upperBound`	Optional `includeLowerBound` / `includeUpperBound` (default `true`)
`ExistenceDetail`	—	Field must be present and non-null
`NonExistenceDetail`	—	Field must be absent or null
`RegexDetail`	`value` (pattern)	Full Java-regex syntax
`VersioningDetail`	`type` (`ABOVE`/`BELOW`/`EQUAL`), `value`	Optional `excludeBase` (default `false`)
`ContainsDetail`	`value` (substring)	Case-sensitive
`AnyDetail`	—	Always matches

`lhs` field paths¶

In the playground, use simple dot-notation JSONPath expressions:

$.age          → event["age"]
$.user.city    → event["user"]["city"]
$.order.amount → event["order"]["amount"]

Full JSONPath expressions (filters, wildcards, array indexing) require the Java engine.