Fold large graphs

foldGraph answers what to collapse, never what the collapsed nodes should look like. Your renderer owns the resulting node IDs, dimensions, labels, and data.

import { foldGraph } from 'ego-graph/fold';

const plan = foldGraph(graph, {
  threshold: 10,
  expandedRoots: new Set(['important-branch']),
  isSatellite: (node) => node.type === 'shared-attribute',
  isStructural: (edge) => edge.type !== 'same-ip',
});

for (const fold of plan.folds) {
  console.log(fold.rootId, fold.memberIds, fold.internalEdgeCount);
}

The shallowest branch whose total weight is greater than threshold folds first. Hold one fold open with expandedRoots and the rule applies again to its children, so nested drill-down works naturally.

plan.mergedEdges tells you which original edges are represented by each edge between folded stand-ins. plan.heldOpen returns qualifying roots that were deliberately expanded, which is useful for a “regroup” action.