tsconfig.json

{
  "compilerOptions": {
    "declaration": true,
    "lib": ["dom", "esnext"],
    "module": "commonjs",
    "moduleResolution": "node",
    "outDir": "lib",
    "strict": true,
    "target": "es5"
  },
  "include": ["src"],
  "exclude": ["src/*.test.ts"]
}