tsconfig.json

{
  "compilerOptions": {
    "module": "es2015",
    "outDir": "./dist",
    "declaration": true,
    "declarationMap": false,
    "emitDeclarationOnly": true,
    "sourceMap": false,
    "lib": ["es5", "es6", "es7", "esnext", "dom"],
    "target": "es2018",
    "removeComments": false,
    "esModuleInterop": true,
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "strict": true,
    "skipLibCheck": true,
    "strictPropertyInitialization": false,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "downlevelIteration": true,
    "isolatedModules": true
  },
  "include": ["index.ts"]
}