如何基于TypeScript中的条件在数组对象中创建新属性

type NewPropertyType = boolean;

type AddNewProperty<T extends Array<any>> = T extends Array<infer U> ? Array<U & { isNew: NewPropertyType }> : never;

function addNewProperty<T extends Array<any>>(arr: T): AddNewProperty<T> {
  return arr.map((item) => ({ ...item, isNew: true })) as AddNewProperty<T>;
}

const arr = [
  { name: "item1", price: 10 },
  { name: "item2", price: 20 },
  { name: "item3", price: 30 },
];

const newArr = addNewProperty(arr);
console.log(newArr);

[
  { name: "item1", price: 10, isNew: true },
  { name: "item2", price: 20, isNew: true },
  { name: "item3", price: 30, isNew: true },
]