{
  "context": "Tests TypeScript/JavaScript contract mechanisms for external boundary code and request/transaction failure behavior.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Prioritizes boundary",
      "description": "Explains that this external webhook boundary is a high-priority place for contracts.",
      "max_score": 7
    },
    {
      "name": "Structured analysis",
      "description": "Includes preconditions, postconditions, invariants or semantic invariants, and summary sections.",
      "max_score": 8
    },
    {
      "name": "Preconditions",
      "description": "Specifies payload shape obligations including id, data object, amount, status, and invoice identifier requirements.",
      "max_score": 12
    },
    {
      "name": "Postconditions",
      "description": "Specifies guarantees such as normalized return shape and invoice side effect only for paid events.",
      "max_score": 10
    },
    {
      "name": "Semantic invariant",
      "description": "Documents a business rule such as paid invoices are only marked from valid paid provider events with valid amount/invoice id.",
      "max_score": 10
    },
    {
      "name": "TS mechanism",
      "description": "Uses TypeScript-appropriate enforcement such as type guards, invariant/assert functions, schema validation, or validation methods.",
      "max_score": 12
    },
    {
      "name": "No any leakage",
      "description": "Normalizes the raw payload into stable internal types so downstream code need not use any/provider-shaped data.",
      "max_score": 8
    },
    {
      "name": "Clear errors",
      "description": "Malformed payloads fail immediately with clear errors rather than continuing with undefined/NaN/null/defaults.",
      "max_score": 10
    },
    {
      "name": "Request scoped",
      "description": "Notes that in a long-running server the bad webhook should terminate the request/transaction, not the entire process.",
      "max_score": 7
    },
    {
      "name": "Bad cases",
      "description": "Lists or tests known-bad payloads that should trigger contract failures.",
      "max_score": 8
    },
    {
      "name": "Comments docs",
      "description": "Adds comments or documentation for contract assumptions and guarantees near the boundary function.",
      "max_score": 8
    }
  ]
}