remix-project/libs/remixd/tsconfig.lib.json

{   
    "extends": "./tsconfig.json",
    "compilerOptions": {
      /* Basic Options */
      "target": "es6",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
      "declaration": true,                   /* Generates corresponding '.d.ts' file. */
      "strict": true,                         /* Enable all strict type-checking options. */
      "strictPropertyInitialization": false  /* Enable strict checking of property initialization in classes. */
    },
    "include": ["bin", "src", "bin/origins.json"]
}