TypeError：此条件将始终返回 'false'，因为类型 '"id"' 和 '"en"' 没有重叠

Question

我有这样的代码：

interface FirstType {
  id: number;
  email: string;
  lastname: string;
  name: string;
  password: string;
  phone: string;
}

interface SecondType {
  id: number;
  email: string;
  lastname: string;
  name: string;
  password: string;
  phone: string;
  en: LangType;
}

interface LangType {
  name: string;
  surname: string;
}

type ObjType = FirstType | SecondType;

const data: [FirstType, SecondType] = [
  {
    id: 1,
    email: "sd",
    lastname: "ks",
    name: "sd",
    password: "sfd",
    phone: "sdf",
  },
  {
    id: 1,
    email: "sd",
    lastname: "ks",
    name: "sd",
    password: "sfd",
    phone: "sdf",
    en: { name: "a", surname: "b" },
  },
];

const language = "en";

data.map((obj: ObjType) => {
  const newObj: {
    [key: string]: ObjType[keyof ObjType];
  } = { key: obj.id };

  Object.keys(obj).forEach((key) => {
    const typedKey = key as keyof ObjType;

    newObj[key] = obj[typedKey];

    if (typedKey !== "id" && typedKey === language && obj[typedKey]) {
      for (let value in obj[typedKey] as LangType) {
        newObj[value] = obj[typedKey][value];
      }
    }
  });

  return newObj;
});

但我收到打字稿错误： "TypeError: 这个条件总是返回 'false'，因为类型 '"id"' 和 '"en"' 没有重叠。"

如何解决？我尝试了很多东西，但没有任何效果

已更新。现在出现一个新错误：“此条件将始终返回 'false'，因为类型 '"email" | "lastname" | "name" | "password" | "phone"' 和 '"en"' 没有重叠。"

Answer 1

由于您将FirstType 和SecondType 两种不同类型混合在一起，因此您需要从if 语句中排除属性id，因为仅检查出现在SecondType 的属性

key as keyof ObjType; 

可能是id 或en，但仅针对第二个属性进行检查

  if (typedKey !== 'id' && typedKey === language && obj[typedKey]) {

更新答案：

interface FirstType {
  id: number;
  email: string;
  lastname: string;
  name: string;
  password: string;
  phone: string;
}

interface SecondType {
  id: number;
  email: string;
  lastname: string;
  name: string;
  password: string;
  phone: string;
  en: LangType;
}

interface LangType {
  name: string;
  surname: string;
}

type ObjType = FirstType | SecondType

const data: [FirstType, SecondType] = [
  {
    id: 1,
    email: 'sd',
    lastname: 'ks',
    name: 'sd',
    password: 'sfd',
    phone: 'sdf'
  },
  {
    id: 1,
    email: 'sd',
    lastname: 'ks',
    name: 'sd',
    password: 'sfd',
    phone: 'sdf',
    en: { name: 'a', surname: 'b' }
  }
]

const language = 'en'

data.map((obj: ObjType) => {
  const newObj: {
    [key: string]: ObjType[keyof ObjType];
  } = { key: obj.id }

  Object.keys(obj).forEach(key => {
    type Keys = keyof ObjType
    type LangTypeKeys = keyof LangType
    const typedKey: Keys = key as Keys

    newObj[key] = obj[typedKey]

    if (typedKey.toString() === language && obj[typedKey]) {
      const keys : LangTypeKeys[] = Object.keys(obj[typedKey]) as LangTypeKeys[]
      for (let i = 0; i < keys.length; i++) {
        const lang: LangType = obj[typedKey] as unknown as LangType
        newObj[keys[i]] = (lang as LangType)[keys[i]]
      }
    }
  })

  return newObj
})