tsconfig.json

{
  "compilerOptions": {
    // Allow default imports from modules with no default export.
    "allowSyntheticDefaultImports": true,
    // Target latest version of ECMAScript.
    "target": "ESNext",
    // Search under node_modules for non-relative imports.
    "moduleResolution": "node",
    // Enable strictest settings like strictNullChecks & noImplicitAny.
    "strict": true,
    // Import non-ES modules as default imports.
    "esModuleInterop": true,
    // Specify where to look for types.
    "typeRoots": ["./@types", "./node_modules/@types"],
    // Report errors on unused locals.
    "noUnusedLocals": true,
    // Report errors on unused parameters.
    "noUnusedParameters": true,
    "outDir": "lib",
    "module": "commonjs",
    "declaration": true
  },
  "include": ["src"]
}