Method removeTreeNode

packages/react-aria/src/focus/FocusScope.tsx:1045–1078

(scopeRef: ScopeRef)

  }

  removeTreeNode(scopeRef: ScopeRef): void {
    // never remove the root
    if (scopeRef === null) {
      return;
    }
    let node = this.fastMap.get(scopeRef);
    if (!node) {
      return;
    }
    let parentNode = node.parent;
    // when we remove a scope, check if any sibling scopes are trying to restore focus to something inside the scope we're removing
    // if we are, then replace the siblings restore with the restore from the scope we're removing
    for (let current of this.traverse()) {
      if (
        current !== node &&
        node.nodeToRestore &&
        current.nodeToRestore &&
        node.scopeRef &&
        node.scopeRef.current &&
        isElementInScope(current.nodeToRestore, node.scopeRef.current)
      ) {
        current.nodeToRestore = node.nodeToRestore;
      }
    }
    let children = node.children;
    if (parentNode) {
      parentNode.removeChild(node);
      if (children.size > 0) {
        children.forEach(child => parentNode && parentNode.addChild(child));
      }
    }

    this.fastMap.delete(node.scopeRef);
  }

  // Pre Order Depth First
  *traverse(node: TreeNode = this.root): Generator<TreeNode> {