How to declare global variable for ESLint

[ospfranco]

Hi, I'm creating a JSI module and I have registered the module on the global object, here is my index.ts:

export type CoinType = 'ethereum';

declare const WalletCore: {
  createWallet: (
    strength: 128 | 256,
    passphrase?: string
  ) => { mnemonic: string; seed: string };
  importWalletFromMnemonic: (
    seed: string,
    passphrase?: string
  ) => { mnemonic: string; seed: string };
  importWalletFromHexString: (
    hex: string,
    passphrase?: string
  ) => { mnemonic: string; seed: string };
  getAddressForCoin: (coinName: CoinType) => string;
  deriveAddressForCoin: (coinType: CoinType, derivationPath: string) => any;
};

You can see I simply declare a global variable, which works just fine for type checking, the problem comes on the example project, ESLint complains the variable has not been declared anywhere.

I have also declared the variable in the root package.json

"eslintConfig": {
    "root": true,
    "globals": {
      "WalletCore": true
    },

What's the correct way to add a global variable to ESLint so that when the library is a dependency ESLint knows about the global variable?