How to use the idyll-ast.getChildren function in idyll-ast

appendNode(getNodesByName(ast, "div"), "test");

// $ExpectType Node[] || AST
appendNodes(ast, [["strong", [], ["div", ["pre", [], []]]], "test"]);

// $ExpectType Node[] || AST
prependNode(getNodesByName(ast, "div"), "test");

// $ExpectType Node[] || AST
prependNodes(ast, [["strong", [], ["div", ["pre", [], []]]], "test"]);

// $ExpectType TreeNode
createNode("div", { prop1: "prop1", prop2: ["expression", "x=2"] }, []);

// $ExpectType Node[]
getChildren(ast[0]);

// $ExpectType void
walkNodes(ast, (n: Node) => {
    (n as TreeNode)[0] = "funky-name";
});

// $ExpectType Node[]
findNodes(ast, n => n instanceof Array);

// $ExpectType Node
modifyChildren(ast[0], (n: Node) => {
    if (typeof n === "object") {
        n[0] = "somename";
    }
});
// $ExpectType Node[]

const tNode = node => {
    if (getType(node) === 'textnode') return node;

    let name = getNodeName(node);

    let attrs = getProperties(node);
    if (!attrs) {
      attrs = {};
    }
    const children = getChildren(node);
    return {
      component: name,
      ...attrConvert(attrs, node),
      children: children.map(tNode)
    };
  };

let name = getNodeName(node);

    let attrs = getProperties(node);
    if (!attrs) {
      attrs = {};
    }
    const children = getChildren(node);
    return {
      component: name,
      ...attrConvert(attrs, node),
      children: children.map(tNode)
    };
  };

  return splitAST(getChildren(ast)).elements.map(tNode);
};

return node => {
      const type = getType(node);
      const props = getProperties(node);
      const children = getChildren(node);
      if (node.id != 0) {
        if (type === 'var') {
          state.vars.push(node);
        } else if (state[type]) {
          state[type].push(node);
        } else if (storeElements) {
          state.elements.push(node);
        }
        if (
          !children ||
          (children.length === 1 && getType(children[0]) === 'textnode')
        ) {
          return;
        }
        children.forEach(handleNode(false));
      }