{
  "context": "This criteria evaluates the engineer's proficiency in using Jest's expect.extend API to create custom matchers, and their understanding of how jest-expect-message maintains compatibility with these custom matchers. The focus is on proper implementation of custom matcher functions with correct return values and message functions.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "expect.extend usage",
      "description": "Uses expect.extend() to register all four custom matchers (toBeValidPrice, toBeInStock, toHaveCategory, toHaveAllTags)",
      "max_score": 25
    },
    {
      "name": "Matcher return structure",
      "description": "Each custom matcher returns an object with 'pass' (boolean) and 'message' (function returning string) properties as required by Jest's expect.extend API",
      "max_score": 20
    },
    {
      "name": "toBeValidPrice implementation",
      "description": "Implements toBeValidPrice matcher that correctly validates positive numbers with at most 2 decimal places, checking both the numeric value and decimal precision",
      "max_score": 10
    },
    {
      "name": "toBeInStock implementation",
      "description": "Implements toBeInStock matcher that checks if product.stock > 0",
      "max_score": 10
    },
    {
      "name": "toHaveCategory implementation",
      "description": "Implements toHaveCategory matcher that accepts an expected category parameter and compares it with product.category",
      "max_score": 10
    },
    {
      "name": "toHaveAllTags implementation",
      "description": "Implements toHaveAllTags matcher that accepts an array of expected tags and verifies all are present in product.tags",
      "max_score": 10
    },
    {
      "name": "Negation support",
      "description": "All matchers provide appropriate error messages for both positive and negative cases (with and without .not), using conditional logic based on the 'pass' value",
      "max_score": 10
    },
    {
      "name": "Jest-expect-message compatibility",
      "description": "The custom matchers work correctly when used with jest-expect-message's custom message syntax: expect(value, 'custom message').toCustomMatcher()",
      "max_score": 5
    }
  ]
}