tsconfig.json

{
  "compilerOptions": {
    // We don't want to check node_modules
    "skipLibCheck": true,
    // @TODO: perhaps "emitDeclarationOnly" should be used here (build fails with it), need to
    //       investigate further https://www.typescriptlang.org/tsconfig#emitDeclarationOnly
    //       probably need to update rollup and its config
    "noEmit": true,
    "declaration": true,
    "declarationMap": true,
    "declarationDir": "./dist/types",
    // Since we're using a bundler (rollup), and so TS isn't used to emit JS,
    // this option should be set to "bundler"
    // https://www.typescriptlang.org/docs/handbook/modules/reference.html#bundler
    // However "module": "node16" or "nodenext" is a better option:
    // https://www.typescriptlang.org/docs/handbook/modules/theory.html#module-resolution-for-libraries
    // Also this should be applied too: https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax
    "moduleResolution": "bundler",
    // "moduleResolution" = "bundler" requires this to be "esnext"
    "module": "esnext",
    // Node.js 18 supports up to ES2022 according to https://www.npmjs.com/package/@tsconfig/node18
    // This matters for the generated CJS and ESM file, UMD file is down-leveled further to support IE11
    // (only the syntax, URL, URLSearchParams, fetch is not IE11 compatible) with the help of Babel.
    "target": "es2022",
    "lib": ["ESNext", "dom"],
    "strict": true,
    "noImplicitReturns": true
  },
  "include": ["src"]
}