function isInExportDefault(node) {
  /** @type {ASTNode | null} */
  let parent = node.parent
  while (parent) {
    if (parent.type === 'ExportDefaultDeclaration') {
      return true
    }
    parent = parent.parent
  }
  return false
}
Checks whether the given node is in export default.
@param {ASTNode} node
@returns {boolean}