Nextjs window.ethereum, environment variable 타이핑

global.d.ts

declare global {
  interface Window {
    ethereum?: any;
  }

  namespace NodeJS {
    interface ProcessEnv {
      NEXT_PUBLIC_ERC721_CA: string;
    }
  }
}

export const ethereum = window.ethereum;

tsconfig.json

{
  ...
  "include": [
    "global.d.ts",
    "next-env.d.ts",
    "**/*.ts",
    "**/*.tsx"
  ],
  ...
}