Function getStateNodes

packages/core/src/stateUtils.ts:617–651

(
  stateNode: AnyStateNode,
  stateValue: StateValue
)

 * @param stateValue The state value or State instance
 */
export function getStateNodes(
  stateNode: AnyStateNode,
  stateValue: StateValue
): Array<AnyStateNode> {
  if (typeof stateValue === 'string') {
    const childStateNode = stateNode.states[stateValue];
    if (!childStateNode) {
      throw new Error(
        `State '${stateValue}' does not exist on '${stateNode.id}'`
      );
    }
    return [stateNode, childStateNode];
  }

  const childStateKeys = Object.keys(stateValue);
  const childStateNodes: Array<AnyStateNode> = childStateKeys
    .map((subStateKey) => getStateNode(stateNode, subStateKey))
    .filter(Boolean);

  return [stateNode.machine.root, stateNode].concat(
    childStateNodes,
    childStateKeys.reduce((allSubStateNodes, subStateKey) => {
      const subStateNode = getStateNode(stateNode, subStateKey);
      if (!subStateNode) {
        return allSubStateNodes;
      }
      const subStateNodes = getStateNodes(
        subStateNode,
        stateValue[subStateKey]!
      );

      return allSubStateNodes.concat(subStateNodes);
    }, [] as Array<AnyStateNode>)
  );
}

function transitionAtomicNode<
  TContext extends MachineContext,