TypeScript嵌套对象类型报错：为何仅第一个对象提示属性不存在？

我尝试为包含嵌套对象的变量定义类型时遇到错误，错误提示为：

Object literal may only specify known properties, and '"0x63564c40"' does not exist in type 'Network'.

相关代码如下：

export interface Network {
  network: {
    chainId: string;
    rpcUrls: string[];
    chainName: string;
    nativeCurrency: {
      name: string;
      symbol: string;
      decimals: number;
    };
    blockExplorerUrls: string[];
    iconUrls: string[];
  };
}

export const networkParams: Network = {
  "0x63564c40": {
    chainId: "0x63564c40",
    rpcUrls: ["https://api.harmony.one"],
    chainName: "Harmony Mainnet",
    nativeCurrency: { name: "ONE", decimals: 18, symbol: "ONE" },
    blockExplorerUrls: ["https://explorer.harmony.one"],
    iconUrls: ["https://harmonynews.one/wp-content/uploads/2019/11/slfdjs.png"],
  },
  "0xa4ec": {
    chainId: "0xa4ec",
    rpcUrls: ["https://forno.celo.org"],
    chainName: "Celo Mainnet",
    nativeCurrency: { name: "CELO", decimals: 18, symbol: "CELO" },
    blockExplorerUrl: ["https://explorer.celo.org"],
    iconUrls: ["https://celo.org/images/marketplace-icons/icon-celo-CELO-color-f.svg"],
  },
};

请问为何仅第一个对象触发该错误，第二个对象却没有？

核心原因：接口定义与实际变量结构不匹配 #

你定义的Network接口要求对象必须包含network字段，但实际的networkParams是一个以链ID字符串为键、链配置对象为值的字典结构，完全不符合接口约定。TypeScript检测到你传入的对象里没有network属性，反而存在0x63564c40这种接口未定义的属性，因此抛出错误。

为什么第二个对象没触发相同错误？ #

第二个对象里存在拼写错误：把blockExplorerUrls写成了blockExplorerUrl（少了末尾的s）。TypeScript的错误检测逻辑会优先处理内层对象的属性不匹配问题，同时由于外层已经存在类型不匹配的错误，后续键的错误被暂时抑制了。如果你修正第二个对象的拼写错误，会发现0xa4ec也会触发同样的未知属性错误。

修复方案 #

修正Network接口的定义，让它匹配实际的字典结构：

// 定义单个链的配置类型
export interface ChainConfig {
  chainId: string;
  rpcUrls: string[];
  chainName: string;
  nativeCurrency: {
    name: string;
    symbol: string;
    decimals: number;
  };
  blockExplorerUrls: string[];
  iconUrls: string[];
}

// 定义以链ID为键的字典类型（两种写法二选一）
export type Network = Record<string, ChainConfig>;
// 或者：export interface Network { [chainId: string]: ChainConfig; }

export const networkParams: Network = {
  "0x63564c40": {
    chainId: "0x63564c40",
    rpcUrls: ["https://api.harmony.one"],
    chainName: "Harmony Mainnet",
    nativeCurrency: { name: "ONE", decimals: 18, symbol: "ONE" },
    blockExplorerUrls: ["https://explorer.harmony.one"],
    iconUrls: ["https://harmonynews.one/wp-content/uploads/2019/11/slfdjs.png"],
  },
  "0xa4ec": {
    chainId: "0xa4ec",
    rpcUrls: ["https://forno.celo.org"],
    chainName: "Celo Mainnet",
    nativeCurrency: { name: "CELO", decimals: 18, symbol: "CELO" },
    blockExplorerUrls: ["https://explorer.celo.org"], // 修正拼写错误
    iconUrls: ["https://celo.org/images/marketplace-icons/icon-celo-CELO-color-f.svg"],
  },
};

内容的提问来源于stack exchange，提问作者Furkan Öztürk