{
  "context": "Tests whether the agent uses modern UICollectionView APIs correctly: stable identifiers in diffable data source snapshots, type-safe CellRegistration stored as a property, the correct initial-load and update methods, compositional layout, and configuration-based cell styling with state-driven background handling.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Stable snapshot IDs",
      "description": "The diffable data source snapshot stores Contact IDs (e.g., UUID or Int) as item identifiers, NOT full Contact model structs",
      "max_score": 14
    },
    {
      "name": "CellRegistration stored property",
      "description": "UICollectionView.CellRegistration is stored as a lazy property (or instance property) on the view controller, NOT created inside the cell provider closure",
      "max_score": 14
    },
    {
      "name": "No string-based dequeue",
      "description": "Does NOT use string-based register/dequeue methods (register(_:forCellWithReuseIdentifier:) / dequeueReusableCell(withReuseIdentifier:for:))",
      "max_score": 10
    },
    {
      "name": "Initial load method",
      "description": "Uses applySnapshotUsingReloadData(_:) (or applySnapshotUsingReloadData(_:completion:)) for the initial population of the collection view",
      "max_score": 12
    },
    {
      "name": "reconfigureItems for update",
      "description": "The updateContact method uses reconfigureItems(_:) on the snapshot (not reloadItems) to update a contact's name",
      "max_score": 12
    },
    {
      "name": "Compositional layout",
      "description": "Uses UICollectionViewCompositionalLayout (not UICollectionViewFlowLayout or a custom layout subclass)",
      "max_score": 10
    },
    {
      "name": "UIContentConfiguration for content",
      "description": "Uses UIContentConfiguration (e.g., UIListContentConfiguration) to set cell content (name/email text) rather than directly setting cell.textLabel or subview labels",
      "max_score": 10
    },
    {
      "name": "configurationUpdateHandler for selection",
      "description": "Uses configurationUpdateHandler on the cell to apply background styling based on selection/highlight state, rather than overriding isSelected or setSelected(_:animated:)",
      "max_score": 10
    },
    {
      "name": "Unique item identifiers",
      "description": "The 20 mock contacts all have distinct IDs — no duplicate identifiers in the initial snapshot",
      "max_score": 8
    }
  ]
}