function cloneStoreState()

in packages/recoil/core/Recoil_Snapshot.js [276:322]
42 lines of code
3 McCabe index (conditional complexity)

function cloneStoreState(
  store: Store,
  treeState: TreeState,
  bumpVersion: boolean = false,
): StoreState {
  const storeState = store.getState();
  const version = bumpVersion ? getNextTreeStateVersion() : treeState.version;
  return {
    currentTree: bumpVersion
      ? {
          // TODO snapshots shouldn't really have versions because a new version number
          // is always assigned when the snapshot is gone to.
          version,
          stateID: version,
          transactionMetadata: {...treeState.transactionMetadata},
          dirtyAtoms: new Set(treeState.dirtyAtoms),
          atomValues: treeState.atomValues.clone(),
          nonvalidatedAtoms: treeState.nonvalidatedAtoms.clone(),
        }
      : treeState,
    commitDepth: 0,
    nextTree: null,
    previousTree: null,
    knownAtoms: new Set(storeState.knownAtoms), // FIXME here's a copy
    knownSelectors: new Set(storeState.knownSelectors), // FIXME here's a copy
    transactionSubscriptions: new Map(),
    nodeTransactionSubscriptions: new Map(),
    nodeToComponentSubscriptions: new Map(),
    queuedComponentCallbacks_DEPRECATED: [],
    suspendedComponentResolvers: new Set(),
    graphsByVersion: new Map().set(version, store.getGraph(treeState.version)),
    retention: {
      referenceCounts: new Map(),
      nodesRetainedByZone: new Map(),
      retainablesToCheckForRelease: new Set(),
    },
    // FIXME here's a copy
    // Create blank cleanup handlers for atoms so snapshots don't re-run
    // atom effects.
    nodeCleanupFunctions: new Map(
      mapIterable(storeState.nodeCleanupFunctions.entries(), ([key]) => [
        key,
        () => {},
      ]),
    ),
  };
}