{
  "context": "This criteria evaluates how well the engineer uses the mixin-deep package to merge configuration objects while properly handling custom constructor objects. The focus is on utilizing mixin-deep's built-in capability to preserve custom class instances during deep merging operations.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Uses mixin-deep",
      "description": "Imports and uses the mixin-deep package (typically with require('mixin-deep') or import) as the core merging mechanism",
      "max_score": 30
    },
    {
      "name": "Passes multiple sources",
      "description": "Correctly passes all source configuration objects to mixin-deep, handling the variadic ...sources parameter appropriately",
      "max_score": 20
    },
    {
      "name": "Handles empty object",
      "description": "Uses an empty object {} as the first argument to mixin-deep to avoid mutating the source objects",
      "max_score": 25
    },
    {
      "name": "Leverages built-in preservation",
      "description": "Relies on mixin-deep's native behavior to preserve custom constructor objects without adding custom type checking or handling logic",
      "max_score": 25
    }
  ]
}