@nodebraid/plugin-duplicate-selection

Package is not publicly released

This name identifies the current source module boundary; it is not an npm availability claim.

The problem it solves

Applications should not copy Kernel entities, infer Edge closure, or maintain a second Selection model. This package keeps the complete stable behavior behind one deep Module while the application continues to own new NodeId and EdgeId values.

Public Interface

• duplicateSelectionCommand: the input-free selection.duplicate Command returning CanvasCommit | null;
• createDuplicateSelectionPlugin(): installs the independent Behavior Plugin;
• createDuplicateSelectionShortcutPlugin(): independently contributes focused Ctrl/Cmd+D;
• DuplicateIdMaterializer: synchronously returns one complete Node/Edge ID mapping;
• DuplicateSelectionError: INVALID_CONFIG | INVALID_MATERIALIZATION | STALE_DUPLICATE | SELECTION_UPDATE_FAILED.

The Behavior copies the exactly selected Nodes and their internal Edges. Nodes retain type, size, and opaque data references and receive a { x: 24, y: 24 } world offset by default. Selected parents, port-qualified Endpoints, self-loops, and parallel Edges are remapped one-to-one. Boundary-crossing Edges, edge-only Selection, and unselected descendants do not expand the copy scope.

The application supplies IDs only. NodeBraid validates the complete mapping, exact-root/ABA evidence, and internal Edge closure, creates every duplicate in one synchronous Transaction, then maps the original Selection members to duplicates. Undo removes duplicates and reconciles Selection; Redo restores Document state without reselecting.

The Shortcut Plugin does not subscribe to Renderer Input. It registers through the single authority in @nodebraid/plugin-interaction. If the Behavior is unavailable, Mod+D becomes an explicit capability-unavailable Input Rejection.

Non-goals

Clipboard transport/codec, Serialization, Persistence, deep cloning, business entity factories, async Transactions, collaborative duplication, and Tool Registry remain out of scope. Shared subgraph capture/materialization now comes from the pure @nodebraid/canvas-fragment package.