tsconfig.json

{
  "compilerOptions": {
    "outDir": "dist",
    "target": "ES2018",
    "lib": ["ESNext"],
    "module": "commonjs",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "resolveJsonModule": true,
    "allowSyntheticDefaultImports": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "allowJs": false,
    "checkJs": false,
    "declaration": true,
    "alwaysStrict": true,
    "strict": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictPropertyInitialization": true,
    "strictBindCallApply": true,
    "noImplicitAny": true,
    "noImplicitThis": true,
    "noFallthroughCasesInSwitch": true,
    "noUncheckedIndexedAccess": true,
    // "noUnusedParameters": true,
    // "noUnusedLocals": true,
    "typeRoots": ["node_modules/@types"],
    "types": ["node", "jest"]
  },
  "files": ["src/index.d.ts"]
}