{
  "context": "This criteria evaluates how effectively the engineer uses Jest's expect.extend API to create custom matchers. It focuses on proper matcher registration, implementation of matcher functions with correct return structure, and utilization of matcher context utilities.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "expect.extend usage",
      "description": "Uses expect.extend() to register custom matchers correctly",
      "max_score": 25
    },
    {
      "name": "Matcher return structure",
      "description": "Custom matcher function returns an object with 'pass' boolean and 'message' function properties as required by Jest's matcher interface",
      "max_score": 25
    },
    {
      "name": "Matcher context access",
      "description": "Accesses matcher context properties such as this.isNot to handle negated assertions properly, or this.utils for formatting error messages",
      "max_score": 20
    },
    {
      "name": "Error message formatting",
      "description": "Provides clear, descriptive error messages using this.utils helpers like printReceived and printExpected, or custom formatting that includes received value and expected range",
      "max_score": 20
    },
    {
      "name": "Range validation logic",
      "description": "Implements correct range validation logic that handles inclusive boundaries and properly compares numeric values",
      "max_score": 10
    }
  ]
}