Function groupNodeIdentities

src/extraction/index.ts:1803–1815

(
  nodes: readonly NodeIdentity[],
  key: (n: NodeIdentity) => string
)

];

function groupNodeIdentities(
  nodes: readonly NodeIdentity[],
  key: (n: NodeIdentity) => string
): Map<string, NodeIdentity[]> {
  const groups = new Map<string, NodeIdentity[]>();
  for (const n of nodes) {
    const k = key(n);
    const group = groups.get(k);
    if (group) group.push(n);
    else groups.set(k, [n]);
  }
  return groups;
}

/**
 * Pair each node a file had before a re-index with the node that replaces it,