Node Registry

Requirements

• Export NodeRegistry as named and default. Each instance has set(node, value), get(node), has(node), and delete(node). Keys are Node references, including elements, text nodes, comments, and documents.
• set returns the registry itself for chaining and replaces an existing value for that exact node. get returns the value or undefined if missing.
• has distinguishes a missing key from a key explicitly storing undefined. delete returns true for an existing key and false otherwise.
• Use a WeakMap. Do not add identifiers/properties to DOM nodes, serialize nodes, or keep an extra strong collection of keys. Garbage collection itself is not deterministically testable.
• Node identity matters: clones or visually identical nodes are separate keys. Moving or detaching a node does not change its identity. Keep registry instances independent; store values by reference.

Examples

Input: const registry = new NodeRegistry();
registry.set(element, { visited: true });
registry.get(element);
Output: { visited: true }

Input: registry.set(element, undefined);
registry.has(element);
Output: true